Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.
A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.
The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.
Renewal or physiological repair of damaged nerve tissue.
Conditions which produce injury or dysfunction of the second cranial or optic nerve, which is generally considered a component of the central nervous system. Damage to optic nerve fibers may occur at or near their origin in the retina, at the optic disk, or in the nerve, optic chiasm, optic tract, or lateral geniculate nuclei. Clinical manifestations may include decreased visual acuity and contrast sensitivity, impaired color vision, and an afferent pupillary defect.
The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.
Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.
The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve.
A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.
The cochlear part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The cochlear nerve fibers originate from neurons of the SPIRAL GANGLION and project peripherally to cochlear hair cells and centrally to the cochlear nuclei (COCHLEAR NUCLEUS) of the BRAIN STEM. They mediate the sense of hearing.
The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.
A class of nerve fibers as defined by their nerve sheath arrangement. The AXONS of the unmyelinated nerve fibers are small in diameter and usually several are surrounded by a single MYELIN SHEATH. They conduct low-velocity impulses, and represent the majority of peripheral sensory and autonomic fibers, but are also found in the BRAIN and SPINAL CORD.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot.
A major nerve of the upper extremity. In humans, the fibers of the median nerve originate in the lower cervical and upper thoracic spinal cord (usually C6 to T1), travel via the brachial plexus, and supply sensory and motor innervation to parts of the forearm and hand.
Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.
Injuries to the PERIPHERAL NERVES.
Treatment of muscles and nerves under pressure as a result of crush injuries.
A major nerve of the upper extremity. In humans, the fibers of the ulnar nerve originate in the lower cervical and upper thoracic spinal cord (usually C7 to T1), travel via the medial cord of the brachial plexus, and supply sensory and motor innervation to parts of the hand and forearm.
The 7th cranial nerve. The facial nerve has two parts, the larger motor root which may be called the facial nerve proper, and the smaller intermediate or sensory root. Together they provide efferent innervation to the muscles of facial expression and to the lacrimal and SALIVARY GLANDS, and convey afferent information for TASTE from the anterior two-thirds of the TONGUE and for TOUCH from the EXTERNAL EAR.
A sensory branch of the trigeminal (5th cranial) nerve. The ophthalmic nerve carries general afferents from the superficial division of the face including the eyeball, conjunctiva, upper eyelid, upper nose, nasal mucosa, and scalp.
The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.
Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.
Long, pliable, cohesive natural or manufactured filaments of various lengths. They form the structure of some minerals. The medical significance lies in their potential ability to cause various types of PNEUMOCONIOSIS (e.g., ASBESTOSIS) after occupational or environmental exposure. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p708)
A thioester hydrolase which acts on esters formed between thiols such as DITHIOTHREITOL or GLUTATHIONE and the C-terminal glycine residue of UBIQUITIN.
The 31 paired peripheral nerves formed by the union of the dorsal and ventral spinal roots from each spinal cord segment. The spinal nerve plexuses and the spinal roots are also included.
Nerve fibers liberating catecholamines at a synapse after an impulse.
Use of electric potential or currents to elicit biological responses.
An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)
Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.
Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.
A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.
NERVE GROWTH FACTOR is the first of a series of neurotrophic factors that were found to influence the growth and differentiation of sympathetic and sensory neurons. It is comprised of alpha, beta, and gamma subunits. The beta subunit is responsible for its growth stimulating activity.
A major nerve of the upper extremity. In humans the fibers of the radial nerve originate in the lower cervical and upper thoracic spinal cord (usually C5 to T1), travel via the posterior cord of the brachial plexus, and supply motor innervation to extensor muscles of the arm and cutaneous sensory fibers to extensor regions of the arm and hand.
Differentiated tissue of the central nervous system composed of NERVE CELLS, fibers, DENDRITES, and specialized supporting cells.
A TEXTILE fiber obtained from the pappus (outside the SEEDS) of cotton plant (GOSSYPIUM). Inhalation of cotton fiber dust over a prolonged period can result in BYSSINOSIS.
Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.
A branch of the trigeminal (5th cranial) nerve. The mandibular nerve carries motor fibers to the muscles of mastication and sensory fibers to the teeth and gingivae, the face in the region of the mandible, and parts of the dura.
Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.
Calcitonin gene-related peptide. A 37-amino acid peptide derived from the calcitonin gene. It occurs as a result of alternative processing of mRNA from the calcitonin gene. The neuropeptide is widely distributed in neural tissue of the brain, gut, perivascular nerves, and other tissue. The peptide produces multiple biological effects and has both circulatory and neurotransmitter modes of action. In particular, it is a potent endogenous vasodilator.
Mechanical compression of nerves or nerve roots from internal or external causes. These may result in a conduction block to nerve impulses (due to MYELIN SHEATH dysfunction) or axonal loss. The nerve and nerve sheath injuries may be caused by ISCHEMIA; INFLAMMATION; or a direct mechanical effect.
The 9th cranial nerve. The glossopharyngeal nerve is a mixed motor and sensory nerve; it conveys somatic and autonomic efferents as well as general, special, and visceral afferents. Among the connections are motor fibers to the stylopharyngeus muscle, parasympathetic fibers to the parotid glands, general and taste afferents from the posterior third of the tongue, the nasopharynx, and the palate, and afferents from baroreceptors and CHEMORECEPTOR CELLS of the carotid sinus.
The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.
Diseases of the peripheral nerves external to the brain and spinal cord, which includes diseases of the nerve roots, ganglia, plexi, autonomic nerves, sensory nerves, and motor nerves.
Twelve pairs of nerves that carry general afferent, visceral afferent, special afferent, somatic efferent, and autonomic efferent fibers.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
Contractile tissue that produces movement in animals.
The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.
The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.
The property of nonisotropic media, such as crystals, whereby a single incident beam of light traverses the medium as two beams, each plane-polarized, the planes being at right angles to each other. (Cline et al., Dictionary of Visual Science, 4th ed)
Regularly spaced gaps in the myelin sheaths of peripheral axons. Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
The 1st cranial nerve. The olfactory nerve conveys the sense of smell. It is formed by the axons of OLFACTORY RECEPTOR NEURONS which project from the olfactory epithelium (in the nasal epithelium) to the OLFACTORY BULB.
Method of measuring and mapping the scope of vision, from central to peripheral of each eye.
Examination of the interior of the eye with an ophthalmoscope.
Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.
Bundles of actin filaments (ACTIN CYTOSKELETON) and myosin-II that span across the cell attaching to the cell membrane at FOCAL ADHESIONS and to the network of INTERMEDIATE FILAMENTS that surrounds the nucleus.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
The total area or space visible in a person's peripheral vision with the eye looking straightforward.
Injuries to the optic nerve induced by a trauma to the face or head. These may occur with closed or penetrating injuries. Relatively minor compression of the superior aspect of orbit may also result in trauma to the optic nerve. Clinical manifestations may include visual loss, PAPILLEDEMA, and an afferent pupillary defect.
Peripheral, autonomic, and cranial nerve disorders that are associated with DIABETES MELLITUS. These conditions usually result from diabetic microvascular injury involving small blood vessels that supply nerves (VASA NERVORUM). Relatively common conditions which may be associated with diabetic neuropathy include third nerve palsy (see OCULOMOTOR NERVE DISEASES); MONONEUROPATHY; mononeuropathy multiplex; diabetic amyotrophy; a painful POLYNEUROPATHY; autonomic neuropathy; and thoracoabdominal neuropathy. (From Adams et al., Principles of Neurology, 6th ed, p1325)
Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
A technique of diagnostic imaging of RETINA or CORNEA of the human eye involving the measurement and interpretation of polarizing ELECTROMAGNETIC WAVES such as radio or light waves. It is helpful in the diagnosis of GLAUCOMA; MACULAR DEGENERATION; and other retinal disorders.
Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.
Neurons which activate MUSCLE CELLS.
The major nerves supplying sympathetic innervation to the abdomen. The greater, lesser, and lowest (or smallest) splanchnic nerves are formed by preganglionic fibers from the spinal cord which pass through the paravertebral ganglia and then to the celiac ganglia and plexuses. The lumbar splanchnic nerves carry fibers which pass through the lumbar paravertebral ganglia to the mesenteric and hypogastric ganglia.
Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.
A sensory branch of the MANDIBULAR NERVE, which is part of the trigeminal (5th cranial) nerve. The lingual nerve carries general afferent fibers from the anterior two-thirds of the tongue, the floor of the mouth, and the mandibular gingivae.
The 11th cranial nerve which originates from NEURONS in the MEDULLA and in the CERVICAL SPINAL CORD. It has a cranial root, which joins the VAGUS NERVE (10th cranial) and sends motor fibers to the muscles of the LARYNX, and a spinal root, which sends motor fibers to the TRAPEZIUS and the sternocleidomastoid muscles.
The pressure of the fluids in the eye.
Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.
Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
Glaucoma in which the angle of the anterior chamber is open and the trabecular meshwork does not encroach on the base of the iris.
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).
A branch of the facial (7th cranial) nerve which passes through the middle ear and continues through the petrotympanic fissure. The chorda tympani nerve carries taste sensation from the anterior two-thirds of the tongue and conveys parasympathetic efferents to the salivary glands.
An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.
The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.
Axons of certain cells in the DENTATE GYRUS. They project to the polymorphic layer of the dentate gyrus and to the proximal dendrites of PYRAMIDAL CELLS of the HIPPOCAMPUS. These mossy fibers should not be confused with mossy fibers that are cerebellar afferents (see NERVE FIBERS).
Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.
Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.
The twelve spinal nerves on each side of the thorax. They include eleven INTERCOSTAL NERVES and one subcostal nerve. Both sensory and motor, they supply the muscles and skin of the thoracic and abdominal walls.
The brain stem nucleus that receives the central input from the cochlear nerve. The cochlear nucleus is located lateral and dorsolateral to the inferior cerebellar peduncles and is functionally divided into dorsal and ventral parts. It is tonotopically organized, performs the first stage of central auditory processing, and projects (directly or indirectly) to higher auditory areas including the superior olivary nuclei, the medial geniculi, the inferior colliculi, and the auditory cortex.
Neuroglial cells of the peripheral nervous system which form the insulating myelin sheaths of peripheral axons.
The 6th cranial nerve which originates in the ABDUCENS NUCLEUS of the PONS and sends motor fibers to the lateral rectus muscles of the EYE. Damage to the nerve or its nucleus disrupts horizontal eye movement control.
Nerve fibers liberating acetylcholine at the synapse after an impulse.
A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Branches of the vagus (tenth cranial) nerve. The recurrent laryngeal nerves originate more caudally than the superior laryngeal nerves and follow different paths on the right and left sides. They carry efferents to all muscles of the larynx except the cricothyroid and carry sensory and autonomic fibers to the laryngeal, pharyngeal, tracheal, and cardiac regions.
Traumatic injuries to the facial nerve. This may result in FACIAL PARALYSIS, decreased lacrimation and salivation, and loss of taste sensation in the anterior tongue. The nerve may regenerate and reform its original pattern of innervation, or regenerate aberrantly, resulting in inappropriate lacrimation in response to gustatory stimuli (e.g., "crocodile tears") and other syndromes.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Disease or damage involving the SCIATIC NERVE, which divides into the PERONEAL NERVE and TIBIAL NERVE (see also PERONEAL NEUROPATHIES and TIBIAL NEUROPATHY). Clinical manifestations may include SCIATICA or pain localized to the hip, PARESIS or PARALYSIS of posterior thigh muscles and muscles innervated by the peroneal and tibial nerves, and sensory loss involving the lateral and posterior thigh, posterior and lateral leg, and sole of the foot. The sciatic nerve may be affected by trauma; ISCHEMIA; COLLAGEN DISEASES; and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1363)
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
Benign and malignant neoplasms that arise from one or more of the twelve cranial nerves.
Method of making images on a sensitized surface by exposure to light or other radiant energy.
Type III intermediate filament proteins that assemble into neurofilaments, the major cytoskeletal element in nerve axons and dendrites. They consist of three distinct polypeptides, the neurofilament triplet. Types I, II, and IV intermediate filament proteins form other cytoskeletal elements such as keratins and lamins. It appears that the metabolism of neurofilaments is disturbed in Alzheimer's disease, as indicated by the presence of neurofilament epitopes in the neurofibrillary tangles, as well as by the severe reduction of the expression of the gene for the light neurofilament subunit of the neurofilament triplet in brains of Alzheimer's patients. (Can J Neurol Sci 1990 Aug;17(3):302)
Diseases of the facial nerve or nuclei. Pontine disorders may affect the facial nuclei or nerve fascicle. The nerve may be involved intracranially, along its course through the petrous portion of the temporal bone, or along its extracranial course. Clinical manifestations include facial muscle weakness, loss of taste from the anterior tongue, hyperacusis, and decreased lacrimation.
A tumor made up of nerve cells and nerve fibers. (Dorland, 27th ed)
The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.
Act of eliciting a response from a person or organism through physical contact.
The synapse between a neuron and a muscle.
An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC
Nerves and plexuses of the autonomic nervous system. The central nervous system structures which regulate the autonomic nervous system are not included.
Cell surface receptors that bind NERVE GROWTH FACTOR; (NGF) and a NGF-related family of neurotrophic factors that includes neurotrophins, BRAIN-DERIVED NEUROTROPHIC FACTOR and CILIARY NEUROTROPHIC FACTOR.
A condition in which the intraocular pressure is elevated above normal and which may lead to glaucoma.
The 12th cranial nerve. The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus). This nerve also contains proprioceptive afferents from the tongue muscles.
Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)
Degeneration of distal aspects of a nerve axon following injury to the cell body or proximal portion of the axon. The process is characterized by fragmentation of the axon and its MYELIN SHEATH.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Inflammation of the optic nerve. Commonly associated conditions include autoimmune disorders such as MULTIPLE SCLEROSIS, infections, and granulomatous diseases. Clinical features include retro-orbital pain that is aggravated by eye movement, loss of color vision, and contrast sensitivity that may progress to severe visual loss, an afferent pupillary defect (Marcus-Gunn pupil), and in some instances optic disc hyperemia and swelling. Inflammation may occur in the portion of the nerve within the globe (neuropapillitis or anterior optic neuritis) or the portion behind the globe (retrobulbar neuritis or posterior optic neuritis).
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.
Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).
Atrophy of the optic disk which may be congenital or acquired. This condition indicates a deficiency in the number of nerve fibers which arise in the RETINA and converge to form the OPTIC DISK; OPTIC NERVE; OPTIC CHIASM; and optic tracts. GLAUCOMA; ISCHEMIA; inflammation, a chronic elevation of intracranial pressure, toxins, optic nerve compression, and inherited conditions (see OPTIC ATROPHIES, HEREDITARY) are relatively common causes of this condition.
Nerve fibers which project from cell bodies of AUTONOMIC GANGLIA to SYNAPSES on target organs.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.
Neurons which send impulses peripherally to activate muscles or secretory cells.
The intermediate sensory division of the trigeminal (5th cranial) nerve. The maxillary nerve carries general afferents from the intermediate region of the face including the lower eyelid, nose and upper lip, the maxillary teeth, and parts of the dura.
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC
The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM.
Small sensory organs which contain gustatory receptor cells, basal cells, and supporting cells. Taste buds in humans are found in the epithelia of the tongue, palate, and pharynx. They are innervated by the CHORDA TYMPANI NERVE (a branch of the facial nerve) and the GLOSSOPHARYNGEAL NERVE.
Elements of limited time intervals, contributing to particular results or situations.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
Clusters of neurons and their processes in the autonomic nervous system. In the autonomic ganglia, the preganglionic fibers from the central nervous system synapse onto the neurons whose axons are the postganglionic fibers innervating target organs. The ganglia also contain intrinsic neurons and supporting cells and preganglionic fibers passing through to other ganglia.
Diseases of the sixth cranial (abducens) nerve or its nucleus in the pons. The nerve may be injured along its course in the pons, intracranially as it travels along the base of the brain, in the cavernous sinus, or at the level of superior orbital fissure or orbit. Dysfunction of the nerve causes lateral rectus muscle weakness, resulting in horizontal diplopia that is maximal when the affected eye is abducted and ESOTROPIA. Common conditions associated with nerve injury include INTRACRANIAL HYPERTENSION; CRANIOCEREBRAL TRAUMA; ISCHEMIA; and INFRATENTORIAL NEOPLASMS.
An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.
Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)
The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)
A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.
A paravertebral sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia.
Measurement of ocular tension (INTRAOCULAR PRESSURE) with a tonometer. (Cline, et al., Dictionary of Visual Science, 4th ed)
The nervous system outside of the brain and spinal cord. The peripheral nervous system has autonomic and somatic divisions. The autonomic nervous system includes the enteric, parasympathetic, and sympathetic subdivisions. The somatic nervous system includes the cranial and spinal nerves and their ganglia and the peripheral sensory receptors.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
Nerve fibers which project from parasympathetic ganglia to synapses on target organs. Parasympathetic postganglionic fibers use acetylcholine as transmitter. They may also release peptide cotransmitters.
Diseases of the trigeminal nerve or its nuclei, which are located in the pons and medulla. The nerve is composed of three divisions: ophthalmic, maxillary, and mandibular, which provide sensory innervation to structures of the face, sinuses, and portions of the cranial vault. The mandibular nerve also innervates muscles of mastication. Clinical features include loss of facial and intra-oral sensation and weakness of jaw closure. Common conditions affecting the nerve include brain stem ischemia, INFRATENTORIAL NEOPLASMS, and TRIGEMINAL NEURALGIA.
Diseases of the oculomotor nerve or nucleus that result in weakness or paralysis of the superior rectus, inferior rectus, medial rectus, inferior oblique, or levator palpebrae muscles, or impaired parasympathetic innervation to the pupil. With a complete oculomotor palsy, the eyelid will be paralyzed, the eye will be in an abducted and inferior position, and the pupil will be markedly dilated. Commonly associated conditions include neoplasms, CRANIOCEREBRAL TRAUMA, ischemia (especially in association with DIABETES MELLITUS), and aneurysmal compression. (From Adams et al., Principles of Neurology, 6th ed, p270)
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Nerve fibers which project from sympathetic ganglia to synapses on target organs. Sympathetic postganglionic fibers use norepinephrine as transmitter, except for those innervating eccrine sweat glands (and possibly some blood vessels) which use acetylcholine. They may also release peptide cotransmitters.
Neoplasms which arise from nerve sheaths formed by SCHWANN CELLS in the PERIPHERAL NERVOUS SYSTEM or by OLIGODENDROCYTES in the CENTRAL NERVOUS SYSTEM. Malignant peripheral nerve sheath tumors, NEUROFIBROMA, and NEURILEMMOMA are relatively common tumors in this category.
A low affinity receptor that binds NERVE GROWTH FACTOR; BRAIN-DERIVED NEUROTROPHIC FACTOR; NEUROTROPHIN 3; and neurotrophin 4.
A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.
The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.
A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)
Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.
Transection or severing of an axon. This type of denervation is used often in experimental studies on neuronal physiology and neuronal death or survival, toward an understanding of nervous system disease.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Recording of the changes in electric potential of muscle by means of surface or needle electrodes.
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC
A nervous tissue specific protein which is highly expressed in NEURONS during development and NERVE REGENERATION. It has been implicated in neurite outgrowth, long-term potentiation, SIGNAL TRANSDUCTION, and NEUROTRANSMITTER release. (From Neurotoxicology 1994;15(1):41-7) It is also a substrate of PROTEIN KINASE C.
An increased sensation of pain or discomfort produced by mimimally noxious stimuli due to damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve.
The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.
Neoplasms which arise from peripheral nerve tissue. This includes NEUROFIBROMAS; SCHWANNOMAS; GRANULAR CELL TUMORS; and malignant peripheral NERVE SHEATH NEOPLASMS. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp1750-1)
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
A form of GLAUCOMA in which chronic optic nerve damage and loss of vision normally attributable to buildup of intraocular pressure occurs despite prevailing conditions of normal intraocular pressure.
NERVE FIBERS which project from the central nervous system to AUTONOMIC GANGLIA. In the sympathetic division most preganglionic fibers originate with neurons in the intermediolateral column of the SPINAL CORD, exit via ventral roots from upper thoracic through lower lumbar segments, and project to the paravertebral ganglia; there they either terminate in SYNAPSES or continue through the SPLANCHNIC NERVES to the prevertebral ganglia. In the parasympathetic division the fibers originate in neurons of the BRAIN STEM and sacral spinal cord. In both divisions the principal transmitter is ACETYLCHOLINE but peptide cotransmitters may also be released.
The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Refers to animals in the period of time just after birth.
An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.
Dysfunction of one or more cranial nerves causally related to a traumatic injury. Penetrating and nonpenetrating CRANIOCEREBRAL TRAUMA; NECK INJURIES; and trauma to the facial region are conditions associated with cranial nerve injuries.
Characteristic properties and processes of the NERVOUS SYSTEM as a whole or with reference to the peripheral or the CENTRAL NERVOUS SYSTEM.
A complex network of nerve fibers in the pelvic region. The hypogastric plexus distributes sympathetic fibers from the lumbar paravertebral ganglia and the aortic plexus, parasympathetic fibers from the pelvic nerve, and visceral afferents. The bilateral pelvic plexus is in its lateral extent.
An edible species of the family Ranidae, occurring in Europe and used extensively in biomedical research. Commonly referred to as "edible frog".
Skeletal muscle structures that function as the MECHANORECEPTORS responsible for the stretch or myotactic reflex (REFLEX, STRETCH). They are composed of a bundle of encapsulated SKELETAL MUSCLE FIBERS, i.e., the intrafusal fibers (nuclear bag 1 fibers, nuclear bag 2 fibers, and nuclear chain fibers) innervated by SENSORY NEURONS.
A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A general term indicating inflammation of a peripheral or cranial nerve. Clinical manifestation may include PAIN; PARESTHESIAS; PARESIS; or HYPESTHESIA.
Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)
Clusters of neurons in the somatic peripheral nervous system which contain the cell bodies of sensory nerve axons. Sensory ganglia may also have intrinsic interneurons and non-neuronal supporting cells.
Examination of the angle of the anterior chamber of the eye with a specialized optical instrument (gonioscope) or a contact prism lens.
Methods and procedures for the diagnosis of conditions related to pregnancy, labor, and the puerperium and of diseases of the female genitalia. It includes also demonstration of genital and pregnancy physiology.
Connective tissue comprised chiefly of elastic fibers. Elastic fibers have two components: ELASTIN and MICROFIBRILS.
Two ganglionated neural plexuses in the gut wall which form one of the three major divisions of the autonomic nervous system. The enteric nervous system innervates the gastrointestinal tract, the pancreas, and the gallbladder. It contains sensory neurons, interneurons, and motor neurons. Thus the circuitry can autonomously sense the tension and the chemical environment in the gut and regulate blood vessel tone, motility, secretions, and fluid transport. The system is itself governed by the central nervous system and receives both parasympathetic and sympathetic innervation. (From Kandel, Schwartz, and Jessel, Principles of Neural Science, 3d ed, p766)

Morphogenesis of callosal arbors in the parietal cortex of hamsters. (1/3208)

The morphogenesis of callosal axons originating in the parietal cortex was studied by anterograde labeling with Phaseolus lectin or biocytin injected in postnatal (P) hamsters aged 7-25 days. Some labeled fibers were serially reconstructed. At P7, some callosal fibers extended as far as the contralateral rhinal fissure, with simple arbors located in the homotopic region of the opposite cortical gray matter, and two or three unbranched sprouts along their trajectory. From P7 to P13, the homotopic arbors became more complex, with branches focused predominantly, but not exclusively, in the supra- and infragranular layers of the homotopic region. Simultaneously, the lateral extension of the trunk axon in the white matter became shorter, finally disappearing by P25. Arbors in the gray matter were either bilaminar (layers 2/3 and 5) or supragranular. A heterotopic projection to the lateral cortex was consistently seen at all ages; the heterotopic arbors follow a similar sequence of events to that seen in homotopic regions. These observations document that callosal axons undergo regressive tangential remodeling during the first postnatal month, as the lateral extension of the trunk fiber gets eliminated. Radially, however, significant arborization occurs in layer-specific locations. The protracted period of morphogenesis suggests a correspondingly long plastic period for this system of cortical fibers.  (+info)

Comparative effects of methylmercury on parallel-fiber and climbing-fiber responses of rat cerebellar slices. (2/3208)

The environmental neurotoxicant methylmercury (MeHg) causes profound disruption of cerebellar function. Previous studies have shown that acute exposure to MeHg impairs synaptic transmission in both the peripheral and central nervous systems. However, the effects of MeHg on cerebellar synaptic function have never been examined. In the present study, effects of acute exposure to MeHg on synaptic transmission between parallel fibers or climbing fibers and Purkinje cells were compared in 300- to 350-microm cerebellar slices by using extracellular and intracellular microelectrode-recording techniques. Field potentials of parallel-fiber volleys (PFVs) and the associated postsynaptic responses (PSRs) were recorded in the molecular layer by stimulating the parallel fibers in transverse cerebellar slices. The climbing-fiber responses were also recorded in the molecular layer by stimulating white matter in sagittal cerebellar slices. At 20, 100, and 500 microM, MeHg reduced the amplitude of both PFVs and the associated PSRs to complete block, however, it blocked PSRs more rapidly than PFVs. MeHg also decreased the amplitudes of climbing-fiber responses to complete block. For all responses, an initial increase in amplitude preceded MeHg-induced suppression. Intracellular recordings of excitatory postsynaptic potentials of Purkinje cells were compared before and after MeHg. At 100 microM and 20 microM, MeHg blocked the Na+-dependent, fast somatic spikes and Ca++-dependent, slow dendritic spike bursts. MeHg also hyperpolarized and then depolarized Purkinje cell membranes, suppressed current conduction from parallel fibers or climbing fibers to dendrites of Purkinje cells, and blocked synaptically activated local responses. MeHg switched the pattern of repetitive firing of Purkinje cells generated spontaneously or by depolarizing current injection at Purkinje cell soma from predominantly Na+-dependent, fast somatic spikes to predominantly Ca++-dependent, low amplitude, slow dendritic spike bursts. Thus, acute exposure to MeHg causes a complex pattern of effects on cerebellar synaptic transmission, with apparent actions on both neuronal excitability and chemical synaptic transmission.  (+info)

Electrophysiological evidence for tetrodotoxin-resistant sodium channels in slowly conducting dural sensory fibers. (3/3208)

A tetrodotoxin (TTX)-resistant sodium channel was recently identified that is expressed only in small diameter neurons of peripheral sensory ganglia. The peripheral axons of sensory neurons appear to lack this channel, but its presence has not been investigated in peripheral nerve endings, the site of sensory transduction in vivo. We investigated the effect of TTX on mechanoresponsiveness in nerve endings of sensory neurons that innervate the intracranial dura. Because the degree of TTX resistance of axonal branches could potentially be affected by factors other than channel subtype, the neurons were also tested for sensitivity to lidocaine, which blocks both TTX-sensitive and TTX-resistant sodium channels. Single-unit activity was recorded from dural afferent neurons in the trigeminal ganglion of urethan-anesthetized rats. Response thresholds to mechanical stimulation of the dura were determined with von Frey monofilaments while exposing the dura to progressively increasing concentrations of TTX or lidocaine. Neurons with slowly conducting axons were relatively resistant to TTX. Application of 1 microM TTX produced complete suppression of mechanoresponsiveness in all (11/11) fast A-delta units [conduction velocity (c.v.) 5-18 m/s] but only 50% (5/10) of slow A-delta units (1.5 +info)

C-fiber depletion alters response properties of neurons in trigeminal nucleus principalis. (4/3208)

The effects of C-fiber depletion induced by neonatal capsaicin treatment on the functional properties of vibrissa-sensitive low-threshold mechanoreceptive (LTM) neurons in the rat trigeminal nucleus principalis were examined in adult rats. Neonatal rats were injected either with capsaicin or its vehicle within 48 h of birth. The depletion of unmyelinated afferents was confirmed by the significant decrease in plasma extravasation of Evan's blue dye induced in the hindlimb skin of capsaicin-treated rats by cutaneous application of mustard oil and by the significant decrease of unmyelinated fibers in both the sciatic and infraorbital nerves. The mechanoreceptive field (RF) and response properties of 31 vibrissa-sensitive neurons in capsaicin-treated rats were compared with those of 32 vibrissa-sensitive neurons in control (untreated or vehicle-treated) rats. The use of electronically controlled mechanical stimuli allowed quantitative analysis of response properties of vibrissa-sensitive neurons; these included the number of center- and surround-RF vibrissae within the RF (i.e., those vibrissae which when stimulated elicited >/=1 and <1 action potential per stimulus, respectively), the response magnitude and latency, and the selectivity of responses to stimulation of vibrissae in different directions with emphasis on combining both the response magnitude and direction of vibrissal deflection in a vector analysis. Neonatal capsaicin treatment was associated with significant increases in the total number of vibrissae, in the number of center-RF vibrissae per neuronal RF, and in the percentage of vibrissa-sensitive neurons that also responded to stimulation of other types of orofacial tissues. Compared with control rats, capsaicin-treated rats showed significant increases in the response magnitude to stimulation of surround-RF vibrissae as well as in response latency variability to stimulation of both center- and surround-RF vibrissae. C-fiber depletion also significantly altered the directional selectivity of responses to stimulation of vibrissae. For neurons with multiple center-RF vibrissae, the proportion of center-RF vibrissae with net vector responses oriented toward the same quadrant was significantly less in capsaicin-treated compared with control rats. These changes in the functional properties of principalis vibrissa-sensitive neurons associated with marked depletion of C-fiber afferents are consistent with similarly induced alterations in LTM neurons studied at other levels of the rodent somatosensory system, and indeed may contribute to alterations previously described in the somatosensory cortex of adult rodents. Furthermore, these results provide additional support to the view that C fibers may have an important role in shaping the functional properties of LTM neurons in central somatosensory pathways.  (+info)

Uninjured C-fiber nociceptors develop spontaneous activity and alpha-adrenergic sensitivity following L6 spinal nerve ligation in monkey. (5/3208)

We investigated whether uninjured cutaneous C-fiber nociceptors in primates develop abnormal responses after partial denervation of the skin. Partial denervation was induced by tightly ligating spinal nerve L6 that innervates the dorsum of the foot. Using an in vitro skin-nerve preparation, we recorded from uninjured single afferent nerve fibers in the superficial peroneal nerve. Recordings were made from 32 C-fiber nociceptors 2-3 wk after ligation and from 29 C-fiber nociceptors in control animals. Phenylephrine, a selective alpha1-adrenergic agonist, and UK14304 (UK), a selective alpha2-adrenergic agonist, were applied to the receptive field for 5 min in increasing concentrations from 0.1 to 100 microM. Nociceptors from in vitro control experiments were not significantly different from nociceptors recorded by us previously in in vivo experiments. In comparison to in vitro control animals, the afferents found in lesioned animals had 1) a significantly higher incidence of spontaneous activity, 2) a significantly higher incidence of response to phenylephrine, and 3) a higher incidence of response to UK. In lesioned animals, the peak response to phenylephrine was significantly greater than to UK, and the mechanical threshold of phenylephrine-sensitive afferents was significantly lower than for phenylephrine-insensitive afferents. Staining with protein gene product 9.5 revealed an approximately 55% reduction in the number of unmyelinated terminals in the epidermis of the lesioned limb compared with the contralateral limb. Thus uninjured cutaneous C-fiber nociceptors that innervate skin partially denervated by ligation of a spinal nerve acquire two abnormal properties: spontaneous activity and alpha-adrenergic sensitivity. These abnormalities in nociceptor function may contribute to neuropathic pain.  (+info)

Mechanisms of capsaicin- and lactic acid-induced bronchoconstriction in the newborn dog. (6/3208)

1. Capsaicin activation of the pulmonary C fibre vanilloid receptor (VR1) evokes the pulmonary chemoreflex and reflex bronchoconstriction. Among potential endogenous ligands of C fibre afferents, lactic acid has been suggested as a promising candidate. We tested the hypotheses that (a) lactic acid behaves as a stimulant of C fibre receptors in the newborn dog to cause reflex bronchoconstriction, and (b) lactic acid causes reflex bronchoconstriction via the same pulmonary C fibre receptor mechanism as capsaicin using the competitive capsaicin/VR1 receptor antagonist capsazepine. 2. Right heart injection of lactic acid caused a significant increase (47 +/- 8.0 %) in lung resistance (RL) that was atropine sensitive (reduced by 75 %; P < 0.05), consistent with reflex activation of muscarinic efferents by stimulation of C fibre afferents. 3. Infusion of the competitive capsaicin antagonist capsazepine caused an 80 % reduction (P < 0.01) in the control bronchoconstrictor response (41 +/- 8.5 % increase in RL) to right heart injections of capsaicin. The effects of capsazepine are consistent with reversible blockade of the VR1 receptor to abolish C fibre-mediated reflex bronchoconstriction. 4. Lactic acid-evoked increases in RL were unaffected by VR1 blockade with capsazepine, consistent with a separate lactic acid-induced reflex mechanism. 5. We conclude that (a) putative stimulation of C fibres with lactic acid causes reflex bronchoconstriction in the newborn dog, (b) capsazepine reversibly antagonizes reflex bronchoconstriction elicited by right heart injection of capsaicin, presumably by attenuating capsaicin-induced activation of the C fibre 'capsaicin' receptor (VR1), and (c) capsazepine resistance of lactic acid-induced bronchoconstriction indicates that lactic acid evokes reflex bronchoconstriction by a separate mechanism, possibly via the acid-sensing ionic channel.  (+info)

The size and fibre composition of the corpus callosum with respect to gender and schizophrenia: a post-mortem study. (7/3208)

In this study the cross-sectional area (in n = 14 female controls, 15 male controls, 11 female patients with schizophrenia, 15 male patients with schizophrenia) and fibre composition (in n = 11 female controls, 10 male controls, 10 female patients with schizophrenia, 10 male patients with schizophrenia) of the corpus callosum in post-mortem control and schizophrenic brains was examined. A gender x diagnosis interaction (P = 0.005) was seen in the density of axons in all regions of the corpus callosum except the posterior midbody and splenium. Amongst controls, females had greater density than males; in patients with schizophrenia this difference was reversed. A reduction in the total number of fibres in all regions of the corpus callosum except the rostrum was observed in female schizophrenic patients (P = 0.006; when controlling for brain weight, P = 0.053). A trend towards a reduced cross-sectional area of the corpus callosum was seen in schizophrenia (P = 0.098); however, this is likely to be no more than a reflection of an overall reduction in brain size. With age, all subregions of the corpus callosum except the rostrum showed a significant reduction in cross-sectional area (P = 0.018) and total fibre number (P = 0.002). These findings suggest that in schizophrenia there is a subtle and gender-dependent alteration in the forebrain commissures that may relate to the deviations in asymmetry seen in other studies, but the precise anatomical explanation remains obscure.  (+info)

A glial cell line-derived neurotrophic factor-secreting clone of the Schwann cell line SCTM41 enhances survival and fiber outgrowth from embryonic nigral neurons grafted to the striatum and to the lesioned substantia nigra. (8/3208)

We have developed a novel Schwann cell line, SCTM41, derived from postnatal sciatic nerve cultures and have stably transfected a clone with a rat glial cell line-derived neurotrophic factor (GDNF) construct. Coculture with this GDNF-secreting clone enhances in vitro survival and fiber growth of embryonic dopaminergic neurons. In the rat unilateral 6-OHDA lesion model of Parkinson's disease, we have therefore made cografts of these cells with embryonic day 14 ventral mesencephalic grafts and assayed for effects on dopaminergic cell survival and process outgrowth. We show that cografts of GDNF-secreting Schwann cell lines improve the survival of intrastriatal embryonic dopaminergic neuronal grafts and improve neurite outgrowth into the host neuropil but have no additional effect on amphetamine-induced rotation. We next looked to see whether bridge grafts of GDNF-secreting SCTM41 cells would promote the growth of axons to their striatal targets from dopaminergic neurons implanted orthotopically into the 6-OHDA-lesioned substantia nigra. We show that such bridge grafts increase the survival of implanted embryonic dopaminergic neurons and promote the growth of axons through the grafts to the striatum.  (+info)

Purpose: : To investigate the reproducibility of peripapillary retinal nerve fiber layer thickness (RNFLT) measurements obtained with optical coherence tomography (OCT) in glaucoma patients both before and after a comprehensive ophthalmic examination including Goldmann applanation tonometry and pupillary dilation. To determine if pre-dilation RNFLT measurements differ from those obtained after dilation. Methods: : Prior to examination and prior to instillation of any topical medications, the Stratus OCT was used to perform three consecutive scans of the peripapillary retinal nerve fiber layer (RNFL) of both eyes using the 3.4 mm Fast RNFL protocol. The subjects were allowed a brief rest prior to being repositioned for repeat imaging. Subjects underwent a comprehensive examination including dilation of the pupils with tropicamide 1.0% and phenylephrine 2.5%. During slit-lamp biomicroscopy, the degree of lens opacification was graded using the lens opacities classification system (LOCS) III. After ...
Glaucoma is presumed to be an axonal disease which starts at the lamina cribrosa. This assumption has led to the monitoring of the retinal nerve fiber layer thickness for the diagnosis and monitoring of progression of glaucoma. However, varying disc size, myopia and tilted discs affect the thickness of the retinal nerve fiber layer. This study aims to ascertain the ration of the retinal nerve fiber layer against full retina as a predictor of glaucoma diagnosis and progression ...
Purpose: Central corneal thickness (CCT) has been identified as an independent risk factor for the development and progression of primary open angle glaucoma. No studies to date have evaluated the difference in retinal nerve fiber layer (RNFL) thickness between eyes in patients with asymmetric CCTs. The aim of our study is to evaluate the difference in glaucomatous nerve damage between eyes in patients with asymmetric CCTs.. Methods: This study is a retrospective cohort study that included all patients seen by a single surgeon from July 1 to September 30, 2014 with a diagnosis of primary open angle glaucoma. Subjects with a history of keratoplasty, refractive surgery, or corneal pathology or surgery affecting CCT were excluded. Average retinal nerve fiber layer measurements were obtained with the Spectralis© Ocular Coherence Tomography (OCT).. Results: 143 patients met the inclusion criteria, of whom 60 (41%) were male. The mean age was 67.2 years. Among patients with RNFL difference of more ...
Retinal nerve fiber layer thickness and visual sensitivity using scanning laser polarimetry with variable and enhanced corneal compensation.
Evaluation of Retinal Nerve Fiber Layer Thickness with Spectral Domain Oct in Primary Open Angle Glaucoma and Ocular Hypertension Abstract.
PURPOSE: To present a technique of ocular sectioning that enables continuous histologic measurements of peripapillary retinal nerve fiber layer (RNFL) thickness in a concentric ring around the optic disc, corresponding to similar regions measured by in vivo imaging techniques.. METHODS: Two pig eyes and two normal human eyes were processed using the umbrella technique, in which peripapillary concentric ring sections were obtained, at increasing diameters, all centered on the optic disc. Each histologic ring section contains a continuous circumferential 360 degrees retinal slice, oriented approximately perpendicular to the retinal surface. Every histologic slice contains each axon of the retina, sectioned perpendicular to each axons long axis and at an equal set distance from the disc margin.. RESULTS: Ring sections from pig and human eyes are presented and correlated to known RNFL anatomy. For the two human eyes, peripapillary RNFL thickness was quantified and plotted, resulting in the ...
Results RNFL thickness values, except for lower and upper nasal sectors, were thinner in the myopic eyes than in the hyperopic eyes. Average RNFL thickness and the RNFL thicknesses of the superotemporal, superonasal, inferotemporal and lower temporal sectors were significantly different between the myopic and emmetropic eyes, and average RNFL thickness and the RNFL thicknesses of the upper temporal and inferonasal sectors were significantly different between the hyperopic and emmetropic eyes. The average peripapillary RNFL thickness had a negative correlation with axial length (r=−0.741, p,0.001). However, after correction of the magnification effect, the significant differences disappeared.. ...
The Effect of Soft Contact Lenses During the Measurement of Retinal Nerve Fiber Layer Thickness Using Optical Coherence Tomography
TY - JOUR. T1 - The Histology of Retinal Nerve Fiber Layer Bundles and Bundle Defects. AU - Radius, Ronald L.. AU - Anderson, Douglas R.. PY - 1979/5. Y1 - 1979/5. N2 - The fiber bundle striations recognized clinically in normal monkey eyes appear to be bundles of axons compartmentalized within glial tunnels formed by Mullers-cell processes, when viewed histologically. The dark boundaries that separate individual bundles are the broadened foot endings of these cells near the inner surface of the retina. Within one week after focal retinal photocoagulation, characteristic fundus changes could be seen in experimental eyes. In histologic sections of the involved retina, there was marked cystic degeneration of the retinal nerve fiber layer. Within one month, atrophy of distal axon segments was complete. With the drop-out of damaged axons and thinning of individual fiber bundles, retinal striations became less prominent. The resulting fundus picture in these experimental eyes is similar to fiber ...
Aims To determine the retinal nerve fibre layer (RNFL) thickness at which visual field (VF) damage becomes detectable and associated with structural loss. Methods In a prospective cross-sectional study, 72 healthy and 40 glaucoma subjects (one eye per subject) recruited from an academic institution had VF examinations and spectral domain optical coherence tomography (SD-OCT) optic disc cube scans (Humphrey field analyser and Cirrus HD-OCT, respectively). Comparison of global mean and sectoral RNFL thicknesses with VF threshold values showed a plateau of threshold values at high RNFL thicknesses and a sharp decrease at lower RNFL thicknesses. A broken stick statistical model was fitted to global and sectoral data to estimate the RNFL thickness tipping point where the VF threshold values become associated with the structural measurements. The slope for the association between structure and function was computed for data above and below the tipping point. Results The mean RNFL thickness ...
Results The median RNFL thickness in the group of vitrectomised eyes was significantly higher compared with control eyes at every visit. The analysis of variance showed that the median thickness in vitrectomised eyes differed between visits (F=4,3023; p=0.006). There was no time-related trend for RNFL thickness in this group. The analysis of variance of RNFL thickness in the fellow, unoperated eyes showed no difference between visits (F=2,3426; p=0.075).. ...
Skin biopsy has become a valuable tool in the evaluation of patients with small nerve fiber pathological changes [21]. Skin biopsy represents a well-established, safe, easy, and inexpensive method to quantify small sensory nerve fibers and autonomic nerve fibers in the skin [18]. In contrast, nerve conduction studies are not able to evaluate the function of small nerve fibers. Damage to small nerve fibers has recently been demonstrated in small samples of critically ill patients [29, 30]. Small fiber pathological change may play a role in the pathophysiology of sepsis, e.g., in neuropathic pain syndromes, which often become apparent after recovery from severe illness and after discharge from the ICU [23]. Although sensory problems like neuropathic pain, stocking/glove sensory loss, numbness and pallhypesthesia were evaluated in this study, the majority of patients were not able to report these reliably in the acute phase of sepsis. As neuropathic pain is a problem in the long-term follow up of ...
To compare the diagnostic performance of automated imaging for glaucoma.Prospective, direct comparison study.Adults with suspected glaucoma or ocular hypertension referred to hospital eye services in the United Kingdom.We evaluated 4 automated imaging test algorithms: the Heidelberg Retinal Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany) glaucoma probability score (GPS), the HRT Moorfields regression analysis (MRA), scanning laser polarimetry (GDx enhanced corneal compensation; Glaucoma Diagnostics (GDx), Carl Zeiss Meditec, Dublin, CA) nerve fiber indicator (NFI), and Spectralis optical coherence tomography (OCT; Heidelberg Engineering) retinal nerve fiber layer (RNFL) classification. We defined abnormal tests as an automated classification of outside normal limits for HRT and OCT or NFI ≥ 56 (GDx). We conducted a sensitivity analysis, using borderline abnormal image classifications. The reference standard was clinical diagnosis by a masked glaucoma expert including standardized
Purpose: Scanning laser polarimetry using the GDxVCC was conducted on diabetic and non-diabetic subjects to determine if RNFL (retinal nerve fiber layer) thickness differed between these two cohort groups. Design: Prospective, comparative case series, pilot study Subjects: Forty-four diabetic and forty-two non-diabetic subjects. Methods: Subjects had a one-time office visit, consisting of visual acuities, pupil assessment, angle assessment, intraocular pressures, a GDxVCC scan, and a full fundus exam to determine if there were clinical findings of retinopathy present. Retinopathy was staged using the ETDRS (Early Treatment Diabetic Retinopathy Study) protocol. Conclusion: The RNFL (retinal nerve fiber layer) in diabetic subjects was found to be statistically significantly thinner than the RNFL in non-diabetic subjects, but additional data collection is needed before conclusive results can be obtained.
A Common Glaucoma-risk Variant of SIX6 Alters Retinal Nerve Fiber Layer and Optic Disc Measures in a European Population: The EPIC-Norfolk Eye Study.
The present study did not provide evidence of RNFL thinning in patients with PD. However, VF defects were more frequent in PD patients compared to controls.. A number of previous studies [10-12], although not all [14-16], provided evidence of reduced RNFL thickness in PD patients. Inzelberg et al. [11] reported a reduction in the infero temporal RNFL thickness, which was topographically matched to the VF defects, in a subset of five patients with reliable VFs. A reduction in average RNFL thickness, macular thickness and volume was also reported in another study in PD patients [11]. Decreased RNFL thickness has also been suggested in PD patients examined with scanning laser ophthalmoscopy [21]. Moschos et al. [12] reported reduced temporal and inferior RNFL thickness in PD patients compared to controls. However, in agreement with our results, mean RNFL thickness did not differ between the groups. In addition, OCT findings with spectral domain OCT (SD-OCT) suggest a decreased thickness of the ...
Although the small-diameter primary afferent fibers in the skin promptly respond to nociceptive stimuli and convey sensory inputs to the central nervous system, the neural signatures that underpin the relationship between cutaneous afferent fibers and pain perception remain elusive. We combined skin biopsy at the lateral aspect of the distal leg, which is used to quantify cutaneous afferent fibers, with fMRI, which is used to assess brain responses and functional connectivity, to investigate the relationship between cutaneous sensory nerves and the corresponding pain perception in the brain after applying heat pain stimulation to the dorsum of the right foot in healthy subjects. During painful stimulation, the degree of cutaneous innervation, as measured by epidermal nerve fiber density, was correlated with individual blood oxygen level-dependent (BOLD) signals of the posterior insular cortex and of the thalamus, periaqueductal gray, and rostral ventromedial medulla. Pain perception was associated with
This study focuses on the use of Metanx® as the sole treatment for improving and reversing nerve damage in type 2 diabetic patients with peripheral neuropathy. There will be two equal study groups enrolled in this randomized double blinded study. The minimum sample size of enrollment is 24 (12 per group), which is required for 90% power at alpha = .05. The maximum number of participants will be set at 100 (50 per group). Patients who are pre-diabetic or patients who have been diagnosed with diabetes type II for less than five years are included in this study. The control group will receive placebo pill twice daily versus the treatment group which will receive one Metanx® tablet twice daily. Each group will have intraepidermal nerve fiber densities obtained by skin biopsies taken at the beginning of the study before any treatment has begun as well as a final intraepidermal nerve skin biopsy at the end of twelve months to re-biopsy. In addition each group will answer three sets of questionnaires ...
After nerve damage or repeated stimulation, WDR (wide dynamic range) neurons experience a general increase in excitability.[5] This hyper-excitability can be caused by an increased neuronal response to a noxious stimulus (hyperalgesia), a larger neuronal receptive field, or spread of the hyper-excitability to other segments.[5] This condition is maintained by C fibers.[5] C fibers cause central sensitization of the dorsal horn in the spinal cord in response to their hyperactivity.[5] The mechanism underlying this phenomenon involves the release of glutamate by these pathologically sensitized C fibers.[5] The glutamate interacts with the postsynaptic NMDA receptors, which aids the sensitization of the dorsal horn.[5] Presynaptic neuronal voltage-gated N-calcium channels are largely responsible for the release of this glutamate as well as the neuropeptide, substance P.[5] The expression of presynaptic neuronal voltage-gated N-calcium channels increases after a nerve lesion or repeated ...
Methods Evaluation of the corneal nerve fibre density using CCM in six women with non-length-dependent SFN. The patients were characterised by sensory disturbance involving proximal regions of the limbs, face and trunks, and the diagnosis was confirmed by the findings of decreased intraepidermal nerve fibre density on skin biopsy. ...
Dentate granule cells become synaptically interconnected in the hippocampus of persons with temporal lobe epilepsy, forming a recurrent mossy fiber pathway. This pathway may contribute to the development and propagation of seizures. The physiology of mossy fiber-granule cell synapses is difficult to …
We dont have very precise tools to evaluate the way the nervous system functions. We have electrophysiological studies like EMG and nerve conduction velocity assessments, but theyre often negative in people who have widespread or other localized pain complaints, and people have been told that that means that theres nothing wrong with them. But whats been underappreciated is that an EMG or nerve conduction velocity test only measures the largest nerve fibers and not the small fibers. Small fibers, meaning weakly or unmyelinated nerve fibers, are the ones that control pain or transmit pain information. The large nerve fibers dont. So for years, weve been addressing painful disorders with a tool that doesnt measure the nerve fiber types that are involved in pain processing.. Its been demonstrated in a wide variety of chronic painful conditions, that the major pathological state is the reduction of nerve fiber density in the skin of individuals who have chronic widespread complaints. Weve ...
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The Epidermal Nerve Fiber Density (ENFD) test is an objective method of documenting small fiber peripheral neuropathy by quantifying the terminal branches of peripheral nerves within the epidermis. The test is highly specific and sufficiently sensitive with 97% of accuracy rate. The test is recommended to perform when patients experience the following symptoms: pain and abnormal sensation (burning, prickling, shooting), as well as numbness, tightness, coldness in foot/ankle areas.. The common causes of small fiber peripheral neuropathy are: diabetes, types I & II; HIV; vibratory trauma; amyloidosis / monoclonal gammopathy; alcohol abuse; pharmacologic toxins (metronidazole); solvent exposure, and idiopathic neuropathy, when the cause cant be determined, once thought to represent as much as half of all cases.. The ENFD test can also be used to predict the small nerve fiber peripheral neuropathy.. A small 3×3 mm skin biopsy is used for providing diagnostic information on small nerve fibers. The ...
Glaucomatous damage to the RNFL usually precedes detectable visual field loss; clinical assessment of RNFL optical properties has been valuable in diagnosis of glaucoma and other neuropathic diseases. In this dissertation, we aimed to improve the understanding of the changes of RNFL reflectance and its underlying ultrastructure under the development of glaucoma. We used simultaneous immunohistochemical labeling and both en face and in-depth confocal imaging to study axonal cytoskeletal alteration of F-actin, MTs and NFs across the retina in the context of glaucoma. We have found that alteration of each cytoskeletal components is different from each other, and different degree of RNFL change could happen in the same retina. These findings help to understand selective damage mechanisms of human glaucoma. We proposed a new method to classify RGCs based on the content of each cytoskeletal component in axons, and investigated the cytoskeletal distribution across the retina. We have discovered axonal subtypes
Glaucoma Diagnostic Accuracy of Ganglion Cell-Inner Plexiform Layer Thickness: Comparison with Nerve Fiber Layer and Optic Nerve Head
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RESULTS. The mfVEP amplitude responses (measure of nerve loss) showed abnormal cluster visual field defects in 48.3% of the CIS eyes, while mfVEP latency (measure of demyelination) analysis showed significant delays in 20.7%. OCT average RNFLT (retinal nerve fiber layer thickness. surrogate measure of optic nerve loss) was significantly reduced compared to the control group (P = 0.02). Significant differences between CIS eyes with abnormal and normal mfVEP latencies were found for the OCT RNFLT (P , 0.001) with a longer latency being linked to more severe axonal damage (More demyelination is associated with more nerve loss = more severe disease). OCT average RNFLT was found to be independent predictor of clinically definitive MS diagnosis at twelve months. ...
Linear regression of macular thickness with average peripapillary RNFL thickness (Littmann-adjusted). RNFL = retinal nerve fiber layer, dotted line = N
2 How to assess the retinal nerve fiber layer thickness. Most patients require numerous injections to dry up the swelling or maintain the effect.. Sensory Impairment - Visual Impairment. Blindness is one of the most feared illnesses by Americans ranking fourth after acquired immunodeficiency syndrome cancer and Alzheimers disease.1 The National Lab including Choroid extends from the _____ to the _____: ora serrata/ optic nerve; choroid provides blood Safe For All Wheel Types. The name of a specific carotenoid hydrocarbon is constructed by adding two Greek letters as prefixes to the stem name carotene (beta) (gamma) (epsilon conjunctivitis oral ulcers and stomatitis (1978) Interaction of a combined feline viral rhinotracheitis-feline calicivirus vaccine and the FVR carrier state. Miller Sellner - Sleepy Eye MNUsed Tractors and Farm Equipment - Machinery. Home Safety Tips for Low Vision: More Resources for People with Low Vision For more tips on safety and independent living for people with ...
Tatham A, Boer E, Weinreb R, et al. Glaucomatous Retinal Nerve Fiber Layer Thickness Loss is associated with Slower Reaction Times under a Divided Attention Task - American Journal of Ophthalmology 2014. ...
Approval for this study was obtained from the Institutional Review Board at the University of Virginia. This study is a consecutive series of 13 eyes of 11 patients in whom repeated attempts at OCT imaging failed to yield a good quality study despite the absence of significant media opacity or inadequate pupil dilation. All scans were performed by a trained technician on the same OCT machine (OCT Stratus, Third Generation, Model 3000, software 4.0, Carl Zeiss Ophthalmic Systems, Dublin, CA, USA). For the purpose of this study, an OCT study was considered of good quality if at least four of six (for fast macular imaging) or two of three (for nerve fiber layer imaging) scans had correct edge detection and a signal strength of greater than 6.0. Correct edge detection refers to the correct identification of the inner and outer retinal or retinal nerve fiber layer boundaries by the OCT software thus allowing accurate thickness measurements. Signal strength is the proprietary OCT software parameter ...
Approval for this study was obtained from the Institutional Review Board at the University of Virginia. This study is a consecutive series of 13 eyes of 11 patients in whom repeated attempts at OCT imaging failed to yield a good quality study despite the absence of significant media opacity or inadequate pupil dilation. All scans were performed by a trained technician on the same OCT machine (OCT Stratus, Third Generation, Model 3000, software 4.0, Carl Zeiss Ophthalmic Systems, Dublin, CA, USA). For the purpose of this study, an OCT study was considered of good quality if at least four of six (for fast macular imaging) or two of three (for nerve fiber layer imaging) scans had correct edge detection and a signal strength of greater than 6.0. Correct edge detection refers to the correct identification of the inner and outer retinal or retinal nerve fiber layer boundaries by the OCT software thus allowing accurate thickness measurements. Signal strength is the proprietary OCT software parameter ...
TY - JOUR. T1 - Age and retinal nerve fiber layer thickness measured by spectral domain optical coherence tomography.. AU - Lee, Jong Yeon. AU - Hwang, Young Hoon. AU - Lee, Sun Min. AU - Kim, Yong Yeon. PY - 2012/6/1. Y1 - 2012/6/1. N2 - To evaluate the association between age and peripapillary retinal nerve fiber layer (RNFL) thickness measured by Cirrus high-definition (HD) spectral domain optical coherence tomography (OCT) in healthy Korean subjects. A total of 302 eyes from 155 healthy Korean subjects (age range, 20 to 79 years) underwent RNFL thickness measurements using the Cirrus HD-OCT. Average, quadrant, and clock-hour RNFL thickness parameters were analyzed in terms of age using linear mixed effect models. Average RNFL demonstrated a slope of -2.1 μm per decade of age (p , 0.001). In quadrant analysis, superior (-3.4 μm/decade, p , 0.001) and inferior (-2.9 μm/decade, p , 0.001) quadrants showed steeper slopes, whereas temporal (-1.1 μm/decade, p , 0.001) and nasal (-1.0 ...
BACKGROUND: To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness in glaucomatous Nepalese eyes using spectral domain optical coherence tomography (SD-OCT) and study its relationship with visual field sensitivity. METHODS: A total of 120 eyes comprising primary open angle glaucoma (POAG), glaucoma suspects (GS), normal tension glaucoma (NTG) and healthy subjects (n=30 cases in each group) underwent a complete ophthalmic examination, including optic nerve head (ONH) evaluation and standard automated perimetry (SAP). RNFL thickness measurements around the optic disk were taken with circular spectral domain optical coherence tomography (SD-OCT) scans. Analysis of variance (ANOVA) was used for comparison of RNFL parameters among various study groups. The relationship of RNFL parameters with visual field (VF) global indices was evaluated with regression analysis. RESULTS: The mean pRNFL thickness was significantly less in the POAG (64.30±14.45μm, p,0.01), NTG (85.43±9.79μm, ...
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TY - JOUR. T1 - Diagnostic capability of 3d peripapillary retinal volume for glaucoma using optical coherence tomography customized software. AU - Liu, Yingna. AU - Jassim, Firas. AU - Braaf, Boy. AU - Khoueir, Ziad. AU - Poon, Linda Yi Chieh. AU - Ben-David, Geulah S.. AU - Papadogeorgou, Georgia. AU - Tsikata, Edem. AU - Simavli, Huseyin. AU - Que, Christian. AU - Lee, Ramon. AU - Shieh, Eric. AU - Vakoc, Benjamin J.. AU - Bouma, Brett E.. AU - De Boer, Johannes F.. AU - Chen, Teresa C.. PY - 2019/8. Y1 - 2019/8. N2 - Précis:The diagnostic capability of peripapillary retinal volume is similar to peripapillary retinal nerve fiber layer thickness for diagnosing glaucoma, but with fewer artifacts.Purpose:To compare the diagnostic capability of 3-dimensional peripapillary retinal volume (RV) versus 2-dimensional peripapillary retinal nerve fiber layer (RNFL) thickness for open-angle glaucoma.Patients and Methods:A retrospective cross-sectional analysis was conducted. A total of 180 subjects (113 ...
Aim The aim of this study was to measure retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) complex thickness with Cirrus optical coherence tomography (OCT) in Egyptian multiple sclerosis (MS) patients, and to correlate the OCT findings with the visual functions and neurological conditions. Patients and methods This study design was a cross-sectional one. A total of 40 eyes of 22 MS patients diagnosed according to the McDonald criteria were included in this study. Exclusion criteria were as follows: optic neuritis less than 6 months ago; best-corrected visual acuity (BCVA) less than 0.5; intraocular pressure more than 21 mmHg; cup-to-disc ratio more than 0.5; myopia more than 5 D; and eyes with other ocular or central nervous system diseases. All patients were subjected to the following: full history taking; complete ophthalmic examination, including visual functions (BCVA, color vision, and contrast sensitivity), intraocular pressure, and anterior and posterior segment examination; ...
TY - JOUR. T1 - Retinal Nerve Fiber Structure versus Visual Field Function in Patients with Ischemic Optic Neuropathy. A Test of a Linear Model. AU - Hood, Donald C.. AU - Anderson, Susan. AU - Rouleau, Jacinthe. AU - Wenick, Adam S.. AU - Grover, Larissa K.. AU - Behrens, Myles M.. AU - Odel, Jeffrey G.. AU - Lee, Andrew G.. AU - Kardon, Randy H.. PY - 2008/5. Y1 - 2008/5. N2 - Purpose: To test a linear model relating the regional loss in retinal nerve fiber (RNFL) thickness to the corresponding regional loss in sensitivity with data from patients with previous anterior ischemic optic neuropathy (AION). Design: Case-control study. Participants: Twenty-four individuals with AION and 20 with normal vision were tested. The time since the AION attack ranged from 5.2 months to more than 20.3 years (median, 2.95 years). Methods: Eyes were tested with standard automated perimetry (SAP) and with optical coherence tomography (OCT), both RNFL thickness scans. The average RNFL thickness of the inferior ...
Small nerve fiber quantification in the diagnosis of diabetic sensorimotor polyneuropathy: Comparing corneal confocal microscopy with intraepidermal nerve fiber density Academic Article ...
Looking for online definition of dentoperiosteal fiber group in the Medical Dictionary? dentoperiosteal fiber group explanation free. What is dentoperiosteal fiber group? Meaning of dentoperiosteal fiber group medical term. What does dentoperiosteal fiber group mean?
TY - JOUR. T1 - Factors affecting image acquisition during scanning laser polarimetry. AU - Hoh, Sek Tien. AU - Greenfield, David S.. AU - Liebmann, Jeffrey M.. AU - Maw, Richard. AU - Ishikawa, Hiroshi. AU - Chew, Sek Jin. AU - Ritch, Robert. PY - 1998/7/1. Y1 - 1998/7/1. N2 - BACKGROUND AND OBJECTIVE: To illustrate artifacts that may be encountered during measurement of the peripapillary retinal nerve fiber layer (RNFL) using scanning laser polarimetry (SLP). PATIENTS AND METHODS: A total of 426 patients with a variety of ocular diagnoses underwent RNFL measurements using SLP from June 1996 to April 1997. Scanning was performed by two operators whose reproducibility of measurements had been previously validated. Images were selected to illustrate clinical features that adversely affected measurement of the thickness of the RNFL. RESULTS: Image acquisition was difficult in eyes with corneal grafts or edema, keratic precipitates, anterior uveitis, posterior subcapsular cataract, vitreous opacity ...
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PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
Introduction: The optical coherence tomography (OCT) is part of the detection and monitoring of many retinal and optic nerve diseases. Our study aims to create a normativ..
OCT (Optical Coherence Tomography). ISEC employs the Carl Zeiss Meditec Stratus OCT for detailed cross sectional imaging of the eye. The OCT incorporates optical coherence tomography technology to provide comprehensive imaging and measurement of glaucoma and retinal disease. Currently, Stratus OCT is the gold standard in vivo imaging device for the posterior segment and offers proven reproducibility for disease management.. The Stratus OCT provides real-time cross-sectional images and quantitative analysis of retinal features to optimize the diagnosis and monitoring of retinal disease and for enhanced pre- and post-therapy assessment. The device is beneficial for evaluation of cataract patients, pre- and post-operatively, and for the assessment of early signs of glaucoma and glaucomatous change.. Retinal Nerve Fiber Layer (RNFL) Analysis. Circular scans around the optic nerve head capture RNFL measurement of the peripapillary region. Analyses provide comparison of measurements to a normative ...
Visual defects of glaucoma have been associated with retinal nerve fiber layer (NFL) defects, which can be detected as color and texture difference compared to normal NFL using photographs of NFL. Frequently these defects are asymmetric. A large defect exists in one eye while the other eye maintains its normal features. These evaluations of NFL defects, however, are subjective and two-dimensional. We have quantitated NFL thickness using photogrammetry and have measured its asymmetry in the eyes of human subjects ...
MD- mean deviation, CPSD- corrected pattern standard deviation, CSM- cup shape measure, RNFLT- retinal nerve fibre layer thickness, CDAR- cup disc area ratio, PSD- pattern standard devation. (± 3.99) dB. Only three eyes (2.5%) had MD worse than - 12dB. In previous studies mean MD ranged from - 6 to - 10 Db [18, 19, 22] with a higher percentage of glaucoma patients with MD worse than - 20 dB (11.5%, [18] 7.5% [22].. In our study we had 65 eyes with mild glaucomatous damage (MD > -6 dB), which means maximum patients had early glaucomatous changes and we found statistically significant correlations between HRT II and visual fields (strongest correlation between PSD and rim area). This suggests that this parameter (rim area) may be studied in detail to diagnose preperimetric glaucoma.. From the scatter plots, we noticed that advanced glaucoma patients had a large influence on the relation between topographic parameters and visual field indices. Since our study had only three advanced glaucoma ...
The corneal sub-basal nerve plexus (SNP) is a network of thin, unmyelinated nerve fibers located between the basal epithelium and the Bowmans membrane. Both corneal and systemic diseases such as keratoconus and diabetic can alter the nerve fiber density, thickness and tortuosity. Recent developments of cellular resolution OCT technology allowed for in-vivo visualization and mapping of the corneal SNP. We have developed a fully automated algorithm for segmentation of corneal nerves. The performance of the algorithm was tested on a series of enface UHR-OCT images acquired in-vivo from healthy human subjects. The proposed algorithm traces most of the sub-basal corneal nerves correctly. The achieved processing time and tracing quality are the major advantages of the proposed method. Results show the potential application of proposed method for nerve analysis and morphometric quantification of human sub-basal corneal nerves which is an important tool in corneal related diseases ...
RESULTS: The mean VD (ratio) at the SRL and DRL was statistically significantly lower in patients with POAG (SRL, p,0.001; DRL, p,0.001). In the SRL, the mean±SD VD ratio was 0.34±0.05 in patients with POAG and 0.40±0.02 in normal individuals (p,0.001). In the DRL, the mean (SD) ratio was 0.37±0.05 in patients with POAG and 0.43±0.02 in normal individuals (p,0.001). The mean VD at the SRL was significantly correlated with ganglion cell inner plexiform layer thickness (r=0.42, p=0.04) but not with visual field mean deviation (r=0.4, p=0.06) and retinal nerve fibre layer thickness (r=0.5, p=0.06). The mean VD at the DRL did not show significant correlation with any other glaucoma parameter (p,0.05 ...
Authors: Gharbiya, Magda , Trebbastoni, Alessandro , Parisi, Francesco , Manganiello, Silvia , Cruciani, Filippo , DAntonio, Fabrizia , De Vico, Umberto , Imbriano, Letizia , Campanelli, Alessandra , De Lena, Carlo Article Type: Research Article Abstract: Background: The involvement of retina and its vasculature has been recently described in Alzheimers disease (AD). However, none of the previous works have yet investigated the choroid in vivo. Objective: Spectral domain optical coherence tomography (SD-OCT) and enhanced depth imaging (EDI) technique is non-invasively used to assess choroidal thickness in patients with AD and to determine whether the peripapillary retinal nerve fiber layer (RNFL) and central retinal thickness are reduced compared to normal subjects. Methods: Forty-two eyes of 21 patients (mean age, 73.1 ± 6.9 years) with a diagnosis of mild to moderate AD and 42 eyes of 21 age-matched …control subjects (mean age, 70.3 ± 7.3 years) were included in this prospective, ...
Looking for online definition of commissural nerve fiber in the Medical Dictionary? commissural nerve fiber explanation free. What is commissural nerve fiber? Meaning of commissural nerve fiber medical term. What does commissural nerve fiber mean?
The retina lies in the back of the eye and is a multi-layered tissue which detects visual images. These images are transmitted to the brain through approximately 1 million tiny nerve fibers. These nerve fibers converge in the back of the eye, before going to the brain, into a bundle called the optic nerve. If some or all of the nerve fibers are damaged, visual capability deteriorates.. When the optic nerve becomes inflamed, this condition is called optic neuritis. The nerve tissue becomes swollen and red, and the nerve fibers do not work properly. If many of the nerve fibers are involved, the vision may be dramatically affected, but if the optic neuritis is mild, vision is nearly normal. Optic neuritis can be caused by other diseases and conditions and may affect the optic nerve of one or both eyes.. Some people, especially children, develop optic neuritis following a viral illness such as mumps, measles, or a cold. In others, optic neuritis may occur as a sign of a more serious neurological ...
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Normal tension glaucoma - SciELO.ABSTRACT. Normal tension glaucoma is an optic neuropathy in which the retinal nerve fiber layer thickness is reduced, the optic nerve is pathologically excavated, and ...--Jogo Tension Free Multiplayer FPS - Jogos de Tiro.Jogo Tension Free Multiplayer FPS. Esse jogo é incrivelmente simples. Você acabou de ser largado numa fase cheia de outros jogadores que querem a sua...--DELMAR - HUBBELL : Pára Raios - Chaves Fusíveis - Elos ....Liderança em tecnologia para proteção de sistemas de energia elétrica! - Atendimento de vendas, via e-mail, web, telefone e pessoal . - Assistência Técnica ...--Induscabos - Produtos de Fios e Cabos de Média tensão e ....A Induscabos, líder na produção de fios e cabos elétricos. Possui uma grandiosa planta industrial direcionada para fabricação de cabos de baixa e média tensão.--Dica de filme: Sexual Tension , Blog Para Mocinhos.O filme Sexual Tension (Tensão Sexual) formado por vários curtas-metragens, conta ...
During development, maintenance and repair after injury, reciprocal interactions occur between the peripheral nervous system and the target tissues. In the Papers presented in this thesis, different aspects of such netvetarget influences between peripheral nerve fibres and skeletal tissues dtuing development and repair have been investigated in the rat. Developing rat cartilaginous bone primordia have a richly innervated and vascularised perichondriwn. In addition, larger bones exhibit cartilage canals containing blood vessels and putative sensory nerve fibres. Tills evoked the question if there is a nervous regulation of skeletal development. Denervation of the hind paws of young rats resulted in a deficient length growth but had no influence on the progress of secondary ossification. Since growth is mainly due to events in cartilage, cartilage projecting sensory neurones were identified and examined. Sensory neurones projecting to the rat cartilaginous distal femoral epiphyses were located ...
Osmotic and diffusion permeabilities (Pf and Pd) of invertebrate nerve fibers to tritiated water were measured to determine what water flux studies could reveal about the nerve membrane and to directly test the possibility of active transport of water into or out of invertebrate nerve fibers. Pf/Pd ratios for lobster walking leg nerve fibers were found to be about 20 ± 7 at 14°C. Pd measurements were made for squid giant axons at 25°C. and found to yield a value of 4 x 10-4 cm.-1 sec.-1. When combined with the data of D. K. Hill for Pf, a Pf/Pd ratio of 21 ± 5 is obtained. These Pf/Pd ratios correspond to effective pore radii of about 16 ± 4 angstrom units, according to theories developed by Koefoed-Johnsen and Ussing and independently by Pappenheimer and his colleagues. Variations of water flux ratios with temperatures were studied and apparent activation energies calculated for both diffusion experiments and osmotic filtration experiments using the Arrhenius equation, and found to be ...
One of the earliest and most recognizable eye problems of Huntingtons Disease is a change in eye movements or saccades where there is a lag initiating an eye movement to look at something and/or an involuntary reflex saccadic movement that the person cant control. This loss of eye movement control is quite common. Recent research using Optical Coherence Tomography (OCT) testing that we do right in our offices allows us to study the health of the retinal nerve fiber layer and the health of the nerve fibers around the center of vision, called the macula. What we know is the thinning of the nerve fiber layer on OCT, along with a loss of the macular volume is an indicator of the progression of the disease and can serve to monitor that progression. ...
In terms of anatomy, an auditory nerve fiber is either bipolar or unipolar, with its distal projection being called the peripheral process, and its central projection being called the axon; these two projections are also known as the peripheral axon and the central axon, respectively. The peripheral process is sometimes referred to as a dendrite, although that term is somewhat inaccurate. Unlike the typical dendrite, the peripheral process generates and conducts action potentials, which then jump across the cell body (or soma) and continue to propagate along the central axon. In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma. Both the peripheral process and the axon are myelinated. In humans, there are on average 30,000 nerve fibers within the cochlear nerve.[1] The number of fibers varies significantly across species; the domestic cat, for example, has an average of 50,000 fibers. The peripheral axons of auditory nerve fibers form ...
Spectral-domain OCT circle (3.5 mm) scans of the disc from 89 eyes with an average of 3.28 [range 2-5] scans within 6 months formed a variability (V) group; 47 eyes were early glaucoma or suspects and 42 were healthy controls. 159 eyes from 100 patients (early glaucoma or suspects) with 2 OCT circle scans, 1.7 ± 0.55 yrs. apart, formed the long-term group. All scans were taken with Heidelberg GPME, which acquires follow-up circle scans based on baseline. Circumpapillary retinal nerve fiber layer (cRNFL) thickness measures were obtained for global (G), temporal (T), temporal inferior (TI), and superior (TS) regions. Quantile regression was applied on all metrics of the V group, with the independent variable being the baseline values and dependent variable all follow-up values. The 95% and 5% confidence limits (CI) of each metric defined statistical progressors and statistical improvers of the long-term group. For the reference standard (RS), 4 experts identified progressors by evaluating all ...
The retinal nerve fiber layer can be assessed with imaging techniques such as optical coherence tomography, scanning laser ... "Nerve Fiber Analysis". Glaucoma Associates of Texas. White Rabbit Communications, Inc. 2010. Archived from the original on 26 ... In glaucoma visual field defects result from damage to the retinal nerve fiber layer. Field defects are seen mainly in primary ... Peripheral breakthrough may occur due to damage of nerve fibers. Ring or Double arcuate scotoma: Two arcuate scotomas join ...
With the blood vessels come nerve fibers. Researchers including Alfredson and his team in Sweden believe these nerve fibers to ... This lack of blood supply can lead to the degradation of collagen fibers and inflammation. Tightness in the calf muscles has ... important for individuals with chronic Achilles tendinosis which is classified as the degeneration of collagen fibers. These ...
"Electro-saltatory transmission of nerve impulse and effect of narcosis upon nerve fiber". Am. J. Physiol. 127: 211-27. doi: ... Hursh JB (1939). "Conduction velocity and diameter of nerve fibers". American Journal of Physiology. 127: 131-39. doi:10.1152/ ... Note that these Purkinje fibers are muscle fibers and not related to the Purkinje cells, which are neurons found in the ... "Direct determination of membrane resting potential and action potential in single myelinated nerve fibers". The Journal of ...
Tasaki, I (1954). "Nerve impulses in individual auditory nerve fibers of guinea pig". Journal of Neurophysiology. 17 (2): 97- ... Tasaki, I. The electro-saltatory transmission of the nerve impulse and the effect of narcosis upon the nerve fiber. Am J ... While in Japan, he studied vertebrate nerve fibers and discovered the insulating function of the myelin sheath, a material that ... Tasaki, I (1999). "Rapid structural changes in nerve fibers and cells associated with their excitation processes". The Japanese ...
It is controlled by the deep perineal branch of the pudendal nerve. Activity in the nerve fibers constricts the urethra. The ... The urethrovaginal muscle fibers wrap around the vagina and urethra and contraction leads to constriction of both the vagina ... Weak pelvic floor muscles, intrinsic sphincter damage, or damage to the surrounding nerves and tissue can make the urethral ... The external urethral sphincter originates at the ischiopubic ramus and inserts into the intermeshing muscle fibers from the ...
Capsaicin causes reversible degeneration of epidermal nerve fibers. Notably the capsaicin used for the relief of neuropathic ... Cranial nerves Nerve Neuralgia Neuritis Neuropathy "Taxonomy". International Association for the Study of pain. Archived from ... parallel loss of epidermal nerve fibers and pain sensation". Pain. 81 (1-2): 135-45. doi:10.1016/S0304-3959(99)00007-X. PMID ... Galen also suggested nerve tissue as the transferring route of pain to the brain through the invisible psychic pneuma. The idea ...
... the thin protective layer around the nerve fiber, the basal lamina, is preserved so that, as a damaged fiber regrows, it ... Surgically cutting a nerve severs these basal lamina tubes, and without them to channel the regrowing fibers to their lost ... Because nerves often carry both sensory and motor fibers, motor impairment is a possible side effect of neurectomy. A common ... Cordotomy involves cutting nerve fibers that run up the front/side (anterolateral) quadrant of the spinal cord, carrying heat ...
The pink rim of disc contains nerve fibers. The white cup is a pit with no nerve fibers. As glaucoma advances, the cup enlarges ... "Glaucoma causes Optic Nerve Cupping (atrophy) and Vision Loss". The Eye Digest. The University of Illinois Eye and Ear ... The optic disc is the anatomical location of the eye's "blind spot", the area where the optic nerve and blood vessels enter the ...
This area contains nerve fibers, called glomus bodies. Normally, these nerves respond to changes in body temperature or blood ... This tumor can affect the ear, upper neck, base of the skull, and the surrounding blood vessels and nerves. A glomus jugulare ... The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone. The temporal bone ... Horizontal fractures were thought to be associated with injuries to the facial nerve, and longitudinal with injuries to the ...
Small fiber peripheral neuropathy can damage the nerves that control the sweat glands. The sweat gland nerve fiber density test ... Each sweat gland receives several nerve fibers that branch out into bands of one or more axons and encircle the individual ... "Sweat Gland Nerve Fiber Density". Therapath. Eroschenko, Victor P. (2008). "Integumentary System". DiFiore's Atlas of Histology ... Frey's Syndrome If the auriculotemporal nerve is damaged (most often as a result of a Parotidectomy), excess sweat can be ...
CT neurons belong to a group C nerve fibers; these are unmyelinated, and have slow conduction velocities. CT afferents were ... Nagi, Saad S.; Mahns, David A. (May 2013). "C-tactile Fibers Contribute to Cutaneous Allodynia After Eccentric Exercise". The ... Djouhri, Laiche (2016-02-02). "Electrophysiological evidence for the existence of a rare population of C-fiber low threshold ... "Transcriptional Profiling of Cutaneous MRGPRD Free Nerve Endings and C-LTMRs". Cell Reports. 10 (6): 1007-1019. doi:10.1016/j. ...
It receives fibers from the motor, sensory, and parasympathetic components of the facial nerve and sends fibers that will ... The motor fibers of the facial nerve proper and parasympathetic fibers to the submandibular and pterygopalatine ganglia do not ... Motor fibers are carried via the facial nerve proper. The greater petrosal nerve, which carries preganglionic parasympathetic ... The afferent fibers carrying pain, temperature, and touch from the posterior auricular nerve, as well as those carrying special ...
PMID 16345004 Vision and the dimensions of nerve fibers. Wade NJ. J Hist Neurosci. 2005 Dec;14(4):281-94. doi: 10.1080/ ... Part 1: Nerve cell structure, vitalism, and the nerve impulse. Finger S, Wade NJ. J Hist Neurosci. 2002 Jun;11(2):136-55. doi: ... PMID 15460513 Cover picture of 2004: partial decussation of the optic nerves. Wade NJ. J Hist Neurosci. 2004 Mar;13(1):125-6. ...
... serves a protective function for peripheral nerve fibers. Damaged nerve fibers may regenerate if the cell body is ... It forms the outermost layer of the nerve fiber in the peripheral nervous system. The neurilemma is underlain by the myelin ...
The interthalamic adhesion contains nerve cells and nerve fibers; a few of the latter may cross the middle line, but most of ... It is still uncertain whether the interthalamic adhesion contains fibers that cross the midline - and for this reason, it is ...
The least sensitive are nerve cells and muscle fibers. Very sensitive cells are also oocytes and lymphocytes, although they are ...
Niedergerke, R; Sampfli, R (1953). "[Effect of carbon dioxide on single medullated nerve fibers during determination of ... Niedergerke, R (1953). "[Electrotonus and accommodation of medullated nerve fibers of the frog]". Pflügers Archiv : European ... Coraboeuf, E; Niedergerke, R (1953). "[Effect of carbon dioxide and ph on medullated single fibers of the frog]". Pflügers ... Niedergerke, R (1951). "[Threshold of irritability and conduction speed of the frog nerve under carbondioxide application]". ...
The middle layer consists of nerve cells and nerve fibers; fibers enter it from the parietal lobe through the external capsule ... The superior layer is named the ansa lenticularis, and its fibers, derived from the medullary lamina of the lentiform nucleus, ...
The chambers and the turbinates are covered by a ciliated mucous epithelium ... These nerve fibers reach the olfactory bulbs of ... contains nerve receptors for smell and touch." If that interpretation is correct, and the rhinarium is an extension of the ...
Peripheral breakthrough may occur due to damage of nerve fibers. Ring or Double arcuate scotoma: Two arcuate scotomas join ... visual field defects result from damage to the retinal nerve fiber layer. Field defects are seen mainly in primary open angle ... The type of field defect can help localize where the lesion is located (see figure). A lesion in the optic nerve of one eye ... A lesion at the proximal part of optic nerve of one eye cause, central field defect in one eye and temporal half-field defect ...
... somatosensory nerve fibers. They react to low vibrations (5-15 Hz) and deep static touch such as shapes and edges. Due to a ... Most often, they are associated with sensory nerve endings, when they are known as Merkel nerve endings (also called a Merkel ... and make synaptic contacts with somatosensory afferent nerve fibers. Though it has been reported that Merkel cells are derived ... Merkel nerve ending Merkel cell carcinoma List of keratins expressed in the human integumentary system List of human cell types ...
Perroncito named the split up pieces "dictyosomes". La rigenerazione delle fibre nervose, 1910 - Regeneration of nerve fibers. ... While an assistant at Pavia, he demonstrated with a severed peripheral nerve, that the stump attached to the cell body was able ... He is known for research involving regeneration of peripheral nerves, kinetic behavior of the Golgi apparatus during mitosis, ...
CS1 maint: discouraged parameter (link) C. A. G. Wiersma (1947). "Giant nerve fiber system of the crayfish. A contribution to ... The medial giant interneuron (MG) is an interneuron in the abdominal nerve cord of crayfish. It is part of the system that ...
The loss of auditory nerve fibers or synapses has been simulated by assuming (i) that each afferent fiber operates as a ... Cochlear filtering limits the range of AM rates encoded in individual auditory-nerve fibers. In the auditory nerve, the ... be predicted by substantial loss of auditory-nerve fibers with low spontaneous rates and some loss of auditory-nerve fibers ... However, the auditory nerve contains thousands of fibers. Hence, despite these limiting factors, the properties of sounds are ...
GALAMBOS, R. (Sep 1956). "Suppression of auditory nerve activity by stimulation of efferent fibers to cochlea" (PDF). J ... Its nerve fibres, the olivocochlear bundle (OCB), form part of the vestibulocochlear nerve (VIIIth cranial nerve, also known as ... Efferent Fibers of the Cochlear Nerve and Cochlear Nucleus". In Rasmussen, G. L.; Windle, W. F. (eds.). Neural Mechanisms of ... Winslow and Sachs (1987) found that stimulating the OCB: "...enables auditory nerve fibres to signal changes in tone level with ...
The myelin sheath is a fatty covering that protects nerve fibers. Without it, the nerves in the brain (central nervous system ... the fatty covering which acts as an insulator around nerve fibers throughout the central and peripheral nervous systems. MLD ... CNS) and the peripheral nerves (peripheral nervous system - PNS) which control, among other things the muscles related to ...
The Intraneural Plexus of Fasciculi and Fibers in the Sciatic Nerve. Archives of Neurology and Psychiatry. October 1921. Vol. 6 ...
Miller, L. E.; Jüsten, H. P.; Schölmerich, J.; Straub, R. H. (2000). "The loss of sympathetic nerve fibers in the synovial ... Dibona, G. F. (2000). "Neural control of the kidney: Functionally specific renal sympathetic nerve fibers". American Journal of ... Kin, N. W.; Sanders, V. M. (2006). "It takes nerve to tell T and B cells what to do". Journal of Leukocyte Biology. 79 (6): ... The parasympathetic nervous system in the motor nuclei of cranial nerves III, VII, IX, (control over the pupil and salivary ...
"visceral nerve fibers - definition of visceral nerve fibers in the Medical dictionary - by the Free Online Medical Dictionary, ... Specific nerves include several cranial nerves, specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve, and ... Several parasympathetic nerves come off the vagus nerve as it enters the thorax. One nerve is the recurrent laryngeal nerve, ... sympathetic fibers) to form the nerve of the pterygoid canal. The parasympathetic fibers of the nerve of the pterygoid canal ...
... nerve fibers, interneurons, microglia, astrocytes, and blood vessels. It is made up of 6 layers: olfactory nerve layer, ... The trigeminal nerve senses texture, pain, and temperature of food, exg. the cooling effect of menthol or the burning sensation ... Flavor is perceived by the combination of the sense of taste, sense of smell, and the trigeminal nerve (CN V). The gustatory ... These axons collectively make up the olfactory nerve (CN I) and serve the purpose of mediating the sense of smell. ...
"Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of ... Viscous fiber supplements may be useful in those with diabetes.[99] ... A 2019 review found evidence of benefit from dietary fiber.[78] ... Nerves. *Retina. *Heart. *Diabetic skin disease *Diabetic ...
Neurogenic atrophy, which has a similar effect, is muscle atrophy resulting from damage to the nerve which stimulates the ... which help to regenerate skeletal muscle fibers, and a decrease in sensitivity to or the availability of critical secreted ...
... and other sensory neuropeptides can be released from the peripheral terminals of sensory nerve fibers in the skin, ... Substance P and other sensory neuropeptides can be released from the peripheral terminals of sensory nerve fibers in the skin, ... with an amidation at the C-terminus.[4] Substance P is released from the terminals of specific sensory nerves. It is found in ... When the innervation to substance P nerve terminals is lost, post-synaptic cells compensate for the loss of adequate ...
... containing nerve fibers, connecting the auricles with the ventricles of the heart. The Node of Tawara is also called the ... Node of Tawara: a remnant of primitive fibers found in all mammalian hearts at the base of the interauricular septum, and ...
Stimulation of nociceptive fibers in a pattern consistent with that from inflammation switches on a form of amplification in ... The use of a transcutaneous electrical nerve stimulation device has been shown to alleviate hyperalgesia.[28][29] ... Hyperalgesia is similar to other sorts of pain associated with nerve irritation or damage such as allodynia and neuropathic ... in rats after spinal nerve injury and inflammation". Eur. J. Pharmacol. 510 (3): 223-8. doi:10.1016/j.ejphar.2005.01.033. PMID ...
No photoreceptors are found at the blind spot, the area where ganglion cell fibers are collected into the optic nerve and leave ... The axons of ganglion cells form the two optic nerves. Photoreceptor cells are typically arranged in an irregular but ... When light activates the melanopsin signaling system, the melanopsin-containing ganglion cells discharge nerve impulses that ... resting potential in other nerve cells is usually −65 mV). This depolarization current is often known as dark current. ...
Talk:Accessory obturator nerve. *Talk:Accessory spleen. *Talk:Accessory visual structures. *Talk:Accompanying artery of ... Talk:Association fiber. *Talk:Astrocyte. *Talk:Atlanto-axial joint. *Talk:Atlanto-occipital joint ...
"Physiologists divide nerve-fibers, which form the nerves, into two classes, afferent and efferent. Impressions are made on the ... Thus, nerves carry impulses outward and sensations inward. The activity of these nerves, or rather their fibers, may become ... Efferent nerve-fibers carry impulses out from the center to their endings. Most of these go to muscles and are therefore called ... that vertebral subluxations caused pinched nerves in the intervertebral spaces in favor of subluxations causing altered nerve ...
Types of fibers: Tissue. Purpose. Components. Location Collagenous fibers. Bind bones and other tissues to each other. Alpha ... Connective tissue neoplasms including sarcomas such as hemangiopericytoma and malignant peripheral nerve sheath tumor in ... All connective tissue consists of three main components: fibers (elastic and collagenous fibers),[1] ground substance and cells ... Fibers. Not all types of CT are fibrous. Examples of non-fibrous CT include adipose tissue and blood. Adipose tissue gives " ...
Fibers in the pelvic nerves constitute the main afferent limb of the voiding reflex; the parasympathetic fibers to the bladder ... is innervated by sympathetic nervous system fibers from the lumbar spinal cord and parasympathetic fibers from the sacral ... When the afferent and efferent nerves are both destroyed, as they may be by tumors of the cauda equina or filum terminale, the ... The state of the reflex system is dependent on both a conscious signal from the brain and the firing rate of sensory fibers ...
Efferent nerve fibers of gamma motoneurons also terminate in muscle spindles; they make synapses at either or both of the ends ... dynamic nuclear bag fibers (bag1 fibers), static nuclear bag fibers (bag2 fibers), and nuclear chain fibers.[1][2] ... They convey length information to the central nervous system via afferent nerve fibers. This information can be processed by ... Muscle spindles are found within the belly of muscles, between extrafusal muscle fibers.[b] The specialised fibers that ...
Optical fibers were aligned on the silicon substrate with different arrangements for the displacement sensing. A resolution 10 ... When we breathe, the nerves and muscles of our thoracic cavity create a weak magnetic field. Magnetometers based on ...
... and he studied nerve nets in coelenterates and the structure and physiology of giant nerve fibers in annelids. His studies on ... At the age of 88 Bullock re-established a modeling study on nerve-nets, and built a model that accurately predicted the input- ... nerve nets lead him to be one of the first experimentalists to understand the value and importance of computational techniques ...
"Phase Locking of Auditory-Nerve Fibers to the Envelopes of High-Frequency Sounds: Implications for Sound Localization". Journal ... Phase-locking to stimulus frequencies has been shown in the auditory nerve,[5][6] the cochlear nucleus,[5][7] the inferior ... The auditory nerve then leads to several layers of synapses at numerous nuclei in the auditory brainstem. These nuclei are also ... The hair cells in the cochlea release neurotransmitter as a result, causing action potentials down the auditory nerve. ...
They are all innervated by Aβ fibers, except the mechanorecepting free nerve endings, which are innervated by Aδ fibers. ... Each muscle spindle consists of sensory nerve endings wrapped around special muscle fibers called spindle fibers (also called ... The Merkel nerve endings (also known as Merkel discs) detect sustained pressure. The lamellar corpuscles (also known as ... Mechanosensory free nerve endings detect touch, pressure, stretching, as well as the tickle and itch sensations. Itch ...
... the band of nerve fibers which connects the left side and the right side of the brain. People with schizophrenia also tend to ...
Due to the extended length of axonal fiber tracks, axons are particularly vulnerable to physical trauma to the brain. Thus, ... These include dendritic protein microtubule-associated protein-2 (MAP-2) [137,138], brain-derived nerve growth factor (BDNF) [ ...
Nerve fiber layer. *Ganglion cell layer. *Inner plexiform layer. *Inner nuclear layer ...
Nerve fibers are the result of cell processes and the outgrowths of nerve cells. (Several axons are bound together to form one ... Several nerve fibrils then form one large nerve fiber. Myelin, an electrical insulator, forms around selected axons. ... It allows noninvasive imaging of white matter fiber structure and in addition to mapping can be useful in clinical observations ... Fractional anisotropy a measure often used in diffusion imaging where it is thought to reflect fiber density, axonal diameter, ...
... there is a higher permeability for incoming signals from afferent nerve fibers so that they pass "unfiltered" to the cerebral ...
... and preganglionic autonomic nerve fibers lead to them directly from the central nervous system. The adrenal medulla affects ... Ganglioneuroma, a tumor in the nerve cells of the peripheral nervous system[5] ... Release of catecholamines is stimulated by nerve impulses, and receptors for catecholamines are widely distributed throughout ... receiving innervation from corresponding preganglionic fibers. The cells form clusters around fenestrated capillaries where ...
The brain has ganglia and nerve fibers, has neuroglia and vessels, has different colors (is colored this way or that) and so on ... The light from a star travels over intervening space and causes a disturbance in the optic nerve ending in an occurrence in the ...
In vertebrates, 1 represents the retina and 2 is the nerve fibers, including the optic nerve (3), whereas in the octopus eye, 1 ... നേത്രനാഡി (optic nerve) ദൃഷ്ടിപടലത്തിലേക്കു കടക്കുന്ന ഭാഗത്തെയാണ് അന്ധബിന്ധു (Blind spot ) എന്ന് പറയുന്നത് . പ്രകാശത്തെ ...
... both by the direct action of sympathetic nerve fibers on the heart and by causing the endocrine system to release hormones such ...
The taste buds are innervated by a branch of the facial nerve the chorda tympani, and the glossopharyngeal nerve. Taste ... 194: Sensory Nerves, Brendan J. Canning, Domenico Spina. Springer. Page 341. *^ Costa, M; Brookes, S J H; Hennig, G W (2000). " ... The pharynx is innervated by the pharyngeal plexus of the vagus nerve.[10]:1465 Muscles in the pharynx push the food into the ... Parasympathetic innervation to the ascending colon is supplied by the vagus nerve. Sympathetic innervation is supplied by the ...
"Astrocytic plaques and tufts of abnormal fibers do not coexist in corticobasal degeneration and progressive supranuclear palsy ... Brain and Nerve (in Japanese). 41 (1): 35-44. PMID 2655673.. ...
Nerve supply[edit]. The muscles are innervated by thoraco-abdominal nerves, these are continuations of the T7-T11 intercostal ... Some fibers are occasionally connected with the costoxiphoid ligaments, and the side of the xiphoid process. ... Nerve. segmentally by thoraco-abdominal nerves (T7 to T11) and subcostal (T12). ... Sensory supply is from the 7-12 thoracic nerves Variation[edit]. The sternalis muscle may be a variant form of the pectoralis ...
Nerve fiber. *Optical fiber. References. *^ Harper, Douglas. "fiber". Online Etymology Dictionary.. .mw-parser-output cite. ... Natural fibers. Main article: Natural fiber. Natural fibers develop or occur in the fiber shape, and include those produced by ... Newer fiber designs include extruding fiber that splits into multiple finer fibers. Most synthetic fibers are round in cross- ... Most semi-synthetic fibers are cellulose regenerated fibers. Cellulose regenerated fibers. Cellulose fibers are a subset of man ...
Neurons have a cell body (soma or cyton), dendrites and an axon.[1] Dendrites and axons are nerve fibers. There are about 86 ... A neuron (or neurone) is a nerve cell that carries electrical impulses.[1] Neurons are the basic units of our nervous system. ... In humans, neurogenesis (the origin of new nerve cells) largely ceases during adulthood - but in two brain areas, the ...
The nerve fibres which make up the white matter of the cerebral hemispheres are categorized on the basis of their course and ... The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. In contrast to commissural ... fibers, association fibers connect regions within the same hemisphere of the brain, and projection fibers connect each region ... the olfactory fibers and 2) the non-olfactory fibers.[5] ... Wikimedia Commons has media related to Commissural fibers.. *v ...
This is due to the number of synapses formed by the preganglionic fibers with ganglionic neurons. Postganglionic fibers Nerve ... fibers from the CNS to the ganglion are known as preganglionic fibers. All preganglionic fibers, whether they are in the ... Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are ... sympathetic division or in the parasympathetic division, are cholinergic (that is, these fibers use acetylcholine as their ...
Preganglionic fibers Nerve fiber Noback C, Ruggiero DA, Demarest RJ, Strominger NL (2005). The Human Nervous System: Structure ... fibers from the ganglion to the effector organ are called postganglionic fibers. The neurotransmitters of postganglionic fibers ... all of these exceptions are still stimulated by cholinergic pre ganglionic fibers. In both divisions of the autonomic nervous ... where chromaffin cells function as modified post-ganglionic nerves. Instead of releasing epinephrine and norepinephrine into a ...
C fibers are one class of nerve fiber found in the nerves of the somatic sensory system.[1] They are afferent fibers, conveying ... Group C nerve fibers are one of three classes of nerve fiber in the central nervous system (CNS) and peripheral nervous system ... Group C fibers include postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots (IV ... After a nerve lesion of either C fibers or Aδ fibers, they become abnormally sensitive and cause pathological spontaneous ...
Nerve fibers in the human organ of Corti.. Nomura Y.. Abstract. In the human cochlea, the following characteristics of nerve ... 7. The nerve fibers were found in the organ of Corti lateral to the external spiral bundles. The fibers were running in the ... the number of nerve fibers in the external spiral bundle was small. 2. In the tunnel of Corti, the basilar fibers (afferent) ... 3. The medial fibers were present with the internal spiral bundle and tunnel spiral bundle. These fibers are possibly efferent ...
... Albertino Bigiani bigiani at Thu Mar 21 16:06:35 EST 1996 *Previous message: OPCA: ... Hi! Does anybody know why so many nerve fiber bundles decussate in CNS? I mean, is there any functional reason for that? ... Wouldnt be the same if nerve fiber bundles just travelled through the CNS without crossing the middle line? Thanks in advance ...
L3a_Nerve Fiber Clinicals_Part 2 I have been using this material for 7 years in Neuroscience classes in Medical Schools in 3 ... L3a_Nerve Fiber Clinicals_Part 2 is categorized in the following disciplines: * Academic Support Services/EPortfolios/Learning- ... You just viewed L3a_Nerve Fiber Clinicals_Part 2. Please take a moment to rate this material. ... Peripheral nerve Injury, Dean, Surgical Mx principles of PNI, AIMU, Neuroscience, Seddon classification, Neurotmesis ...
"You give it once and it should last for an extended period of time because it is destroying the fibers," says Mannes. "But the ... When RTX binds to TRPV1, it props open the nerve cells ion channel, letting a whole lot of calcium in. Thats toxic, leading ... "So you gain selectivity because it only acts on TRPV1, which is only on a certain class of fibers, which only transmit pain," ... Inject RTX, as its known, into an aching joint, and itll actually destroy the nerve endings that signal pain. Which means ...
Acetylcholinesterase activity in the efferent nerve fibers of the human inner ear.. Ishii T, Murakami Y, Balogh K Jr. ...
A-beta nerve fibers synonyms, A-beta nerve fibers pronunciation, A-beta nerve fibers translation, English dictionary definition ... of A-beta nerve fibers. n. 1. A slender, elongated, threadlike object or structure. 2. Botany One of the elongated, thick- ... Related to A-beta nerve fibers: afferent nerve fibers, C nerve fibers ... لِيْف vlákno fiber Faser ίνα fibra kuitu fibre vlakno fibra 繊維 섬유 vezel fiber włókno fibra волокно fiber เส้นใย lif sợi 纤维. fi· ...
... Elena G. Zotova1 and Joseph C. Arezzo1,2 ... Elena G. Zotova and Joseph C. Arezzo, "Noninvasive Evaluation of Nerve Conduction in Small Diameter Fibers in the Rat," ...
... Elena G. Zotova1 and Joseph C. Arezzo1,2 ... and C fibers in parallel with the evaluation of fast nerve conduction. ... This method reliably identifies compound action potentials in thinly myelinated fibers conducting at a range of 9-18 m/s (. ... The technique is based on the extraction of rectified multiple unit activity (MUA) from in vivo whole nerve compound responses ...
Nerve Fibers and Terminals: Electron Microscopy after Nauta Staining Message Subject. (Your Name) has forwarded a page to you ... Sections of cat spinal cord and rat mammillary body in which degenerating nerve fibers were stained by the Nauta silver method ... Silver granules were present in the axoplasm of some myelinated fibers and in some of the axon terminals. ...
... to track a nerve fiber spreading through the skin of a zebrafish tail fin (gray). The nerve regeneration was occurring in ... The researcher started out by using a laser to sever nerves in a zebrafishs original tail fin, assuming that the nerves would ... Along with other tools, Rieger is using such imaging to explore how the processes of nerve regeneration and wound healing are ... the nerves regenerated. Rieger suspects the answer to the differing outcomes lies in the fact that the fishs damaged skin ...
Conduction in myelinated nerve fibers was blocked by the application of local pressure to the superficial radial nerve. The ... Afferent fibers were first identified by electrical stimulation of the nerve trunk. Single fiber activity was then determined ... A prevailing view is that peripheral nerve fibers mediating burning are C-fibers and those mediating pricking/stinging are Aδ- ... A Role for Nociceptive, Myelinated Nerve Fibers in Itch Sensation. Matthias Ringkamp, Raf J. Schepers, Steven G. Shimada, Lisa ...
Nerve Fiber Analysis synonyms, Nerve Fiber Analysis pronunciation, Nerve Fiber Analysis translation, English dictionary ... definition of Nerve Fiber Analysis. abbreviation for 1. National Futures Association 2. no fixed abode ... Nerve Fiber Analysis - definition of Nerve Fiber Analysis by The Free Dictionary ... Related to Nerve Fiber Analysis: Nerve fiber layer NFA. abbreviation for 1. (Stock Exchange) (in the US) National Futures ...
An axon or nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from ... a vital insulating sheath composed of lipids and proteins around nerve fibers helps speed the electrical signals or nerve ... An experiment conducted on rats demonstrates that a course of therapy combining the stimulation of nerve fiber growth with ... In our visual system, the optic nerves normally combine at a place called the optic chiasm. ... ...
Minh V.D., Moser K.M. (1971) Threshold Distributions of Phrenic Nerve Motor Fibers: A Factor in Smooth Electrophrenic ... Threshold Distributions of Phrenic Nerve Motor Fibers: A Factor in Smooth Electrophrenic Respiration. ...
Researchers have advanced an old quest to get injured nerves to regenerate. By combining two strategies they achieved about ... Normally, injured nerve fibers, known as axons, cant regenerate. Axons conduct impulses away from the body of the nerve cell, ... Key Advance Reported in Regenerating Nerve Fibers. Researchers have advanced a decades-old quest to get injured nerves to ... "But then we come to another big hurdle." That hurdle is getting the nerve fibers from the eye to hook up to the correct centers ...
A new study sheds light on the properties of nanostructures capable of ensuring an effective integration with nerve cells, an ... Neuron-integrated nanotubes to repair nerve fibers. (Nanowerk News) Carbon nanotubes exhibit interesting characteristics ... This result, which shows the extent to which the integration between nerve cells and these synthetic structures is stable and ... The research has also highlighted the fact that the nerve cells growing on the substratum of nanotubes, thanks to this ...
Find treatment reviews for Intraepidermal nerve fiber density (IENFD) from other patients. Learn from their experiences about ...
Demonstration of axonal flow by the movement of tritium-labeled protein in mature optic nerve fibers. A C Taylor and P Weiss ... Demonstration of axonal flow by the movement of tritium-labeled protein in mature optic nerve fibers ... Demonstration of axonal flow by the movement of tritium-labeled protein in mature optic nerve fibers ... Demonstration of axonal flow by the movement of tritium-labeled protein in mature optic nerve fibers ...
Prevelencce of endometrial nerve fibers [ Time Frame: 18 months ]. Is to determine the prevelence of endometrial nerve fibers ... Endometrial Nerve Fibers Detection in Patients With Different Gynecological Pathologies. The safety and scientific validity of ... The aim of this study is to investigate the prevelence of endometrial nerve fibers in different gynecological pathologies in ... The aim of this study is to investigate the prevelence of endometrial nerve fibers in different gynecological pathologies ...
Mitochondria are specialized subunits inside a cell that produce the cells energy and regulate its metabolism. Research suggests that mitochondria may play a central role in neuronal cell survival because they regulate both energy metabolism and cell death pathways. Using genetic mouse models of Alzheimers disease, researchers from Mayo Clinic have found that mitochondria in the brain are dysfunctional early in the disease. The findings were recently published in the open access journal PLoS ONE.. ...
... to track a nerve fiber spreading through the skin of a zebrafish tail fin (gray). The nerve regeneration was occurring in ... The researcher started out by using a laser to sever nerves in a zebrafishs original tail fin, assuming that the nerves would ... it contributed to the degeneration of the fins nerve fibers [2].. Based on these findings, Rieger wants to see whether similar ... Along with other tools, Rieger is using such imaging to explore how the processes of nerve regeneration and wound healing are ...
Abnormal Epidermal Nerve Fiber Density in Fibromyalgia. • April 14, 2014 ... Evidence of abnormal epidermal nerve fiber density in fibromyalgia: Clinical and immunologic implications. ... Since it is known that similar, large fiber neuropathic lesions may be associated with a cutaneous small fiber neuropathy (SFN ... we sought to determine the prevalence of SFN, as measured by epidermal nerve fiber density (ENFD), in a series of FM patients ...
TagsGabriel Luna, Geoff Lewis, nerve fiber layer, Nikon Small World, retina, Steve Fisher, UCSB. Post navigation. Previous Post ... Nerve Fiber Layer (Nikon Small World Winner). This years Nikon Small World Photomicrography Competition features some amazing ... work including this laser confocal image of a mouse nerve fiber layer on a retinal flatmount at 40X magnification by Gabriel ...
Through use of this technology, they discovered that these fibers, or axons, possess an incredible sensitivity to molecular ... Researchers at Georgetown University have developed a novel technology to precisely measure the sensitivity of nerve fibers ... New technology to measure the sensitivity of nerve fibers that wire up the brain during development. *Download PDF Copy ... But, unlike computers that come with a user and troubleshooting manual, nerve fibers called axons must follow molecular cues to ...
While most nerve fiber structures can be accurately visualized with... ... is able to reveal nerve fibers in the human brain at microscopic resolution. ... is able to reveal nerve fibers in the human brain at microscopic resolution. While most nerve fiber structures can be ... Nolden M., Schubert N., Schmitz D., Müller A., Axer M. (2019) Tracing of Nerve Fibers Through Brain Regions of Fiber Crossings ...
Metanx Effects on Nerve Fiber Density in Neuropathic Diabetics. Official Title ICMJE Metanx Effects on Nerve Fiber Density in ... Increased intraepidermal nerve fiber density [ Time Frame: 1 year ]. If Metanx® is able to reverse nerve damage and improve ... to reverse nerve damage and improve symptoms then the final nerve biopsies will show an increase in intraepidermal nerve fiber ... Metanx Effects on Nerve Fiber Density in Neuropathic Diabetics (SLHN2011-18). The safety and scientific validity of this study ...
How a nerve fiber repairs its cut end: involvement of phospholipase A2 ... How a nerve fiber repairs its cut end: involvement of phospholipase A2 ... How a nerve fiber repairs its cut end: involvement of phospholipase A2 ... How a nerve fiber repairs its cut end: involvement of phospholipase A2 ...
  • C fiber axons are grouped together into what is known as Remak bundles. (
  • [4] The number of C fiber axons in each Remak bundle varies with location. (
  • [3] For example, in a rat model, large bundles of greater than 20 axons are found exiting the L5 dorsal root ganglion , while smaller bundles of average 3 axons are found in distal nerve segments. (
  • A novel noninvasive technique was applied to measure velocity within slow conducting axons in the distal extreme of the sciatic nerve (i.e., digital nerve) in a rat model. (
  • Axons conduct impulses away from the body of the nerve cell, forming connections with other nerve cells or with muscles. (
  • The researchers injured the optic nerves of rats, then used a two-pronged approach to get the axons to regenerate. (
  • As Benowitz's lab had found previously, these growth factors activated genes in the retinal nerve cells, causing new axons to grow into the optic nerve. (
  • Through use of this technology, they discovered that these fibers, or axons, possess an incredible sensitivity to molecular guidance cues that direct the axon's route to its desired destination in the brain. (
  • But, unlike computers that come with a user and troubleshooting manual, nerve fibers called axons must follow molecular cues to find the right targets. (
  • The optical properties of vertebrate nerve axons as related to fiber size. (
  • On the other hand, the nerve fiber found in the filiform papillae of rat tongue usually are thin terminal axons, which are agree to those reported by Bock (1971). (
  • By analogy, if nerve fibers were trees, then the terminal branches of the axons can be viewed as the tree's branches. (
  • Nervous system development requires billions of neurons to migrate to the appropriate locations in the brain and grow nerve fibers (axons) that connect to other nerve cells in an intricate network. (
  • Such intervention could possibly enable damaged axons to regenerate (normally impossible in a mature nervous system) and ultimately restore nerve function. (
  • Although there is wide heterogeneity of SFN causes, the available diagnostic tools detect either abnormal nerve function (functional methods) or loss of axons (morphological methods), irrespective of the underlying etiology. (
  • The study indicated the manner in which immune system B-cells damage axons in the course of MS attacks by hampering the energy production in nerve fiber cells, ultimately bringing about natural death of these cells. (
  • Axons are the long, slender fibers of a neuron that serve as the primary transmission lines of the nervous system, and as bundles they help make up nerves. (
  • P f /P d ratios for lobster walking leg nerve fibers were found to be about 20 ± 7 at 14°C. P d measurements were made for squid giant axons at 25°C. and found to yield a value of 4 x 10 -4 cm. -1 sec. -1 . (
  • The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. (
  • Cross-section of a nerve fiber in intestinal connective tissue showing both myelinated and unmyelinated axons. (
  • The dendrites and axons are also called nerve fibers. (
  • Correlation between Axial Length and Retinal Nerve Fiber Layer Thickness in Myopic Eyes. (
  • Optical coherence tomography (OCT) manufacturers graphically present circumpapillary retinal nerve fiber layer thickness (cpRNFLT) together with normative limits to support clinicians in diagnosing ophthalmic diseases. (
  • In terms of visual hallucinations among the PD subgroups, only retinal nerve fiber layer thickness differed significantly, whereas total macular thickness and the thickness of other retinal layers did not differ. (
  • Comparison of retinal nerve fiber layer thickness measurements in healthy subjects using fourier and time domain optical coherence tomography. (
  • This pilot cross-sectional study aimed to determine age-related changes of the retinal nerve fiber layer (RNFL) thickness in retinal periphery by swept-source optical coherence tomography-based analysis. (
  • Objective: The aim of this work was to assess the thickness of peripapillary retinal nerve fiber layer (RNFL) measured by Swept Source optical coherence tomography (SS-OCT) in patients with Type 2 Diabetes Mellitus (DM). (
  • Conclusion: Optical coherence tomography (OCT) provides non-invasive, quantitative and objective measurement of RNFL thickness, optic nerve head, and RGCL thickness with high resolution and accuracy. (
  • To evaluate the role and ability of optical coherence tomography (OCT) to detect differences in peripapillary retinal nerve fiber layer (RNFL) thickness between normal and glaucomatous eyes and also between different severities of glaucoma. (
  • To study the correlation between serum levels of vitamin B 12 , folic acid, and homocysteine and the severity of diabetic retinopathy and the correlation with retinal nerve fiber layer (RNFL) thinning on spectral domain optical coherence tomography (SD-OCT). (
  • To investigate the effect on optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness measurements of varying the standard 3.4-mm-diameter circle location. (
  • 4,5 Apart from elevated intraocular pressure (IOP), various pressure independent factors represent the main risk factors for loss of retinal nerve fiber layer (RNFL) with subsequent glaucomatous damage in PXF syndrome. (
  • To present full ophthalmologic examination and retinal nerve fiber layer (RNFL) photographs of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) patients showing significant increases in RNFL thickness compared to healthy subjects, but without myelinated retinal fibers. (
  • We found evidence of RNFL hypertrophy in ARSACS patients that may have been interpreted as hypermyelinated retinal fibers in previous reports. (
  • thickness of retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC). (
  • Continued analysis in patients with ocular hypertension and glaucoma should help determine whether RNFL in the periphery with lower nerve tissue reserve might be more susceptible to injury, whether injury to the peripheral RNFL might be easier to detect, and/or whether analysis of the peripheral RNFL thickness could improve clinical diagnosis and follow-up of glaucoma. (
  • Usually retinal nerve fiber layer (RNFL) thinning can be present in ODD. (
  • To compare the retinal nerve fiber layer (RNFL) measurements using two different ocular coherence tomography (OCT) devices: Cirrus Fourier domain OCT and Stratus time domain OCT. To analyze reproducibility of Fourier domain measurements in healthy subjects. (
  • Accurate assessment of the retinal nerve fiber layer (RNFL) is an important component in the diagnosis and management of glaucoma. (
  • Histopathologic studies have reported retinal nerve fiber layer (RNFL) thinning in various neurodegenerative diseases. (
  • 1 Specifically with multiple sclerosis, histopathologic studies have reported retinal nerve fiber layer (RNFL) thinning, and these changes have been correlated with disease activity and white matter lesion volume on neuroradiologic studies, such as magnetic resonance imaging. (
  • [3] Remak bundles in the distal peripheral nerve are clustered with other Remak bundles. (
  • [3] Study of Remak bundles has important implications in nerve regeneration after sustaining injury. (
  • 4. The external spiral bundle increases its fiber count when internal and tunnel spiral bundles were present in the organ of Corti. (
  • 7. The nerve fibers were found in the organ of Corti lateral to the external spiral bundles. (
  • Does anybody know why so many nerve fiber bundles decussate in CNS? (
  • Wouldn't be the same if nerve fiber bundles just travelled through the CNS without crossing the middle line? (
  • Dr. Kim and colleagues studied the results of these collisions on youth football players using a novel MRI method that looks at the strain evident on white matter tracts-the bundles of nerve fibers that carry information between different areas of the brain. (
  • The focus here was on deformations of these fiber bundles," Dr. Kim said. (
  • Normal myelination of anatomic nerve fiber bundles: MR analysis. (
  • PURPOSE In order to establish milestones of brain maturation by MR imaging, we examined the initiation of myelination of fiber bundles and of surrounding white matter. (
  • In 24 sites of 18 fiber bundles in eight cross sections obtained perpendicular to the long axis of the brain stem, we analyzed the initiation of myelination and the age at which fiber bundles become indistinguishable owing to myelination of the surrounding white matter (blurring). (
  • RESULTS The fiber bundles were classified into two groups on the basis of the presence or absence of blurring. (
  • CONCLUSION The time of blurring, when myelinated fiber bundles become indistinguishable from surrounding white matter owing to the initiation of myelination, is considered to be a useful parameter of brain maturation in infancy. (
  • Bundles of these fibers found together are called nerves. (
  • C fibers synapse to second-order projection neurons in the spinal cord at the upper laminae of the dorsal horn in the substantia gelatinosa . (
  • [5] The second-order projection neurons are of the wide dynamic range (WDR) type, which receive input from both nociceptive terminals as well as myelinated A-type fibers. (
  • Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process. (
  • This result, which shows the extent to which the integration between nerve cells and these synthetic structures is stable and efficient, highlights the great potentialities of carbon nanotubes as innovative materials capable of facilitating neuronal regeneration or in order to create a kind of artificial bridge between groups of neurons whose connection has been interrupted. (
  • This is due to the number of synapses formed by the preganglionic fibers with ganglionic neurons. (
  • The neurotransmitters of postganglionic fibers differ: In the parasympathetic division, neurons are cholinergic. (
  • Neurons (Nerve Cells). (
  • In a recent paper in Materials Science and Engineering C, they discovered new techniques to optimize how fibers made from poly-L-lactide, a biodegradable polymer, can be better aligned to resemble neurons and to guide regenerating nerve cells. (
  • Peripheral nerves, which have neurons at the center surrounded by cells called Schwann cells, can also be studied using the nanofiber technique. (
  • Morphometry of intracellularly labeled neurons of the auditory nerve: correlations with functional properties. (
  • Purpose: To investigate the value of temporal retinal nerve fiber layer (RNFLtemporal) thickness in the prediction of malingering. (
  • Thickness of quadrant, average and the 12 different areas around the optic nerve were compared between Cirrus and Stratus. (
  • Group C fibers include postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots (IV fiber). (
  • In the autonomic nervous system, fibers from the ganglion to the effector organ are called postganglionic fibers. (
  • the gray rami communicantes contains no sensory fibers but containsympathetic postganglionic fibers. (
  • Magerl, 1991 ) suggest that activity in thinly myelinated Aδ-fibers may contribute to the sensation of itch. (
  • Small nerve fibers, thinly myelinated Aδ-fibers and unmyelinated C-fibers, can be separated into autonomic (efferent) or sensory (afferent). (
  • The nerve regeneration was occurring in tissue being spontaneously formed to replace a section of a young zebrafish's tail fin that had been lopped off 3 days earlier. (
  • Along with other tools, Rieger is using such imaging to explore how the processes of nerve regeneration and wound healing are coordinated. (
  • By combining two strategies - activating nerve cells' natural growth state and using gene therapy to mute the effects of growth-inhibiting factors - they achieved about three times more regeneration of nerve fibers than previously attained. (
  • When we combined these two therapies - activating the growth program in nerve cells and overcoming the inhibitory signaling - we got very dramatic regeneration," said Benowitz, who is also an associate professor of neurosurgery at Harvard Medical School and holds a Ph.D. in biology/psychobiology. (
  • This three-pronged recipe was designed to reproduce the conditions underlying the growth of nerve fibers during development, leading to a robust regeneration of severed nerve fibers through and beyond a complete spinal cord injury. (
  • Understanding these pathways could help in understanding the process of nerve regeneration," says Greenberg, who is also Professor of Neurology and Neurobiology at Harvard Medical School. (
  • We have investigated the relationships between touch threshold, tactile gnosis, and mechanoreceptor and sensory fiber function after nerve regeneration. (
  • For nerve damage caused by trauma, on the other hand, we need to encourage regeneration. (
  • Corneal subbasal nerve fiber regeneration in myopic patients after laser in situ keratomileusis. (
  • The majority of corneal subbasal nerve fiber regeneration occurred from the stump of corneal subbasal nerve fibers outside the corneal flap, and the remaining growth occurred deep within the stroma. (
  • DALLAS - November 7, 2016 - TissueGen® Inc., developer of ELUTE® fiber, enables controlled sustained delivery of sensitive pharmaceuticals and biologics from biodegradable fibers for advanced drug delivery, nerve regeneration, and tissue engineering. (
  • TissueGen works with leading pharmaceutical, therapeutic, and medical device companies to develop fiber and textile medical devices for use in drug delivery applications such as small diameter vascular grafts and stents, tissue and nerve regeneration, orthopedic devices and sutures. (
  • The axon of a nerve cell. (
  • Silver granules were present in the axoplasm of some myelinated fibers and in some of the axon terminals. (
  • An axon or nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma. (
  • Some synaptic junctions appear partway along an axon as it extends-these are called en passant ("in passing") synapses. (
  • Following transection of a giant axon, the nerve membrane at the cut end is resealed within 5 to 30 minutes. (
  • A threadlike extension of a nerve cell and consists of an axon and myelin sheath (if it is myelinated) in the nervous system. (
  • A peripheral nerve fiber contains an axon, myelin sheath, schwann cells and its endoneurium. (
  • also centripetal, or sensory, fiber, the nerve cell outgrowth, or axon, that together with its membrane transmits excitation from the external and internal receptors to the central nervous system-specifically, to the spinal cord or the various sections of the brain. (
  • The morphological methods include skin biopsies for assessment of sensory fibers using epidermal nerve fiber density (ENFD) and sudomotor fibers using sweat gland nerve fiber density (SGNFD). (
  • the vagus nerves carry sensory fibers associated with reflexes in the gastrointestinal (gi) tract. (
  • Evidence of abnormal epidermal nerve fiber density in fibromyalgia: Clinical and immunologic implications. (
  • Since it is known that similar, large fiber neuropathic lesions may be associated with a cutaneous small fiber neuropathy (SFN), we sought to determine the prevalence of SFN, as measured by epidermal nerve fiber density (ENFD), in a series of FM patients and clinically healthy controls. (
  • The primary outcome measure was the correlation between ESC at the feet and results of skin biopsies including epidermal nerve fiber density (ENFD) and sweat gland nerve fiber density (SGNFD) at the distal leg. (
  • Acetylcholinesterase activity in the efferent nerve fibers of the human inner ear. (
  • the most common, or mixed, type of nerve also contains efferent nerve fibers that lead to the effector organs. (
  • In this study, the authors aimed at gaining further insight in the PNS involvement in FRDA by investigating small nerve fibers in patients. (
  • ESC can be useful in detecting loss of small nerve fibers. (
  • Anatomically, each of these effectors has a dual pattern of innervation consisting of a specific and selective innervation by unmyelinated slowly conducting C-type renal sympathetic nerve fibers in addition to an innervation that is shared among all the effectors. (
  • 1989) where they are probably colocalized with noradrenaline in sympathetic nerve fibers (Gale et al. (
  • Circumpapillary retinal nerve fiber layer (cpRNFL) originating from temporal hemiretina mainly distributed at temporal-upper and lower area of optic disc. (
  • There are no evaluations for Intraepidermal nerve fiber density (IENFD). (
  • In humans, a retrospective analysis of breast cancer specimens from 29 patients revealed that increased sympathetic and decreased parasympathetic nerve density in tumors were associated with poor clinical outcomes and correlated with higher expression of immune checkpoint molecules. (
  • Fig. 8: Expression of immune checkpoint molecules positively and negatively correlates with sympathetic and parasympathetic nerve density, respectively, in human breast cancer samples. (
  • At 6 months after transplantation, repeat scans in 11 of the patients who had neuropathy showed that nerve fiber density and length had improved significantly. (
  • Mean intraepidermal nerve fiber (IENF) density was in the lower normal age-adjusted range, 7.2 ± 2.9/mm (normal ≥7/mm), and was slightly below the normal range in 45% of POTS patients. (
  • They evaluated the intraepidermal nerve fiber (IENF) density in skin-biopsies of the lower leg, and applied clinical assessments of small fiber function in 17 FRDA patients. (
  • [1] They are afferent fibers , conveying input signals from the periphery to the central nervous system. (
  • 6. 85-90% of the afferent fibers went to the internal hair cells, while the remainder went to the external hair cells. (
  • This thesis is concerned with the development of a new distributed-parameter model of the myelinated nerve fiber that includes an adequate representation of the anatomical complexity present at the node of Ranvier, considers the peri-axonal conductance pathway and includes active ionic channels in the axolemmal membrane beneath the myelin sheath. (
  • This years Nikon Small World Photomicrography Competition features some amazing work including this laser confocal image of a mouse nerve fiber layer on a retinal flatmount at 40X magnification by Gabriel Luna out of the Steve Fisher and Geoff Lewis's retinal cell biology group at UC Santa Barbara Neuroscience Research Institute . (
  • TissueGen, Inc. will showcase ELUTE® fiber for advanced pharmaceutical and biologics delivery from biodegradable polymers in Booth 3013 at the Society for Neuroscience's Neuroscience 2016 meeting. (
  • At Neuroscience 2016, explore how TissueGen's patented manufacturing process enables controlled sustained delivery of the broadest range of temperature-sensitive pharmaceuticals and biologics ever possible via biodegradable fiber-based devices to enable medical device developers to achieve breakthroughs across a broad range of medical applications. (
  • Each group will have intraepidermal nerve fiber densities obtained by skin biopsies taken at the beginning of the study before any treatment has begun as well as a final intraepidermal nerve skin biopsy at the end of twelve months to re-biopsy. (
  • Myelinated nerve fibers are present in somatic and autonomic nerves. (
  • The cornea is the most densely innervated tissue in the body, so corneal nerve assessment is extremely sensitive for detecting small sensory nerve fiber damage as compared to other tests including measurement of intra-epidermal nerve fibers in the skin, notes lead investigator Joseph L. (
  • Corneal nerve fibers (CNFs) are composed of unmyelinated C-fibers, which are the first nerve fibers to undergo damage and subsequent repair. (
  • In vivo confocal microscopy revealed that most of the regenerated corneal subbasal nerve fibers in the corneal flap originated from the stump of corneal subbasal nerve fibers outside the ablation zone and extended towards the center of the cornea in all patients. (
  • Approximately 94% of regenerated corneal subbasal nerve fibers (73/78 eyes) regrew vertically into the peripheral central 6-mm circle area 1 month after surgery, 78% (28/36 eyes) grew into the central 3-6 mm area at 2 months, and 23% into the central 3-mm circle area at 3 months. (
  • In addition, there was no significant difference in corneal subbasal nerve fiber regenerative capacity between the basic fibroblast growth factor group and the 20% (v/v) deproteinized extract of calf blood group. (
  • Regenerated corneal subbasal nerve fibers in the corneal flap at 1 month (A), 2 months (B) and 3 months (C) after laser in situ keratomileusis (× 800). (
  • At 1 month after surgery, the regenerated fibers derived from the stump of corneal subbasal nerve fibers outside the incision observed in the circle were assigned a score of 1 in 24 eyes (92.3%) from the laser in situ keratomileusis group and in 49 eyes (94.2%) from the sub-bowman keratomileusis group. (
  • Meanwhile, corneal subbasal nerve fibers from two eyes (3.8%) in the sub-bowman keratomileusis group had reached the 3-6 mm diameter circle area (scores 2) (Figures 2, 3). (
  • Researchers from Massachusetts Eye and Ear/Harvard Medical School have described, for the first time, the adult brain's ability to compensate for a near-complete loss of auditory nerve fibers that link the ear to the brain. (
  • In the article "An Improved Model for the Rate-Level Functions of Auditory-Nerve Fibers" by Peter Heil, Heinrich Neubauer, and Dexter R. F. Irvine, which appeared on pages 15424-15437 of the October 26, 2011 issue, the authors regret a mistake in Equation 7. (
  • The afferent nerve fibers that constitute the afferent nerves are subdivided into groups corresponding to the particular sensory systems-for example, the visual, auditory, or olfactory system. (
  • This study characterizes the cochlear receptor and auditory nerve potentials in a patient with FRDA who had the clinical profile of auditory neuropathy. (
  • The refractory characteristics of auditory nerve fibers limit their ability to accurately encode temporal information. (
  • Furthermore, refractory data are needed for the development of accurate computational models of auditory nerve fibers. (
  • Polarity effects on neural responses of the electrically stimulated auditory nerve at different cochlear sites. (
  • Spontaneous activity of auditory-nerve fibers: insights into stochastic processes at ribbon synapses. (
  • Effect of stimulus level on the temporal response properties of the auditory nerve in cochlear implants. (
  • A point process framework for modeling electrical stimulation of the auditory nerve. (
  • Auditory nerve fiber responses to electric stimulation: modulated and unmodulated pulse trains. (
  • Discharge-rate dependence of refractory behavior of cat auditory-nerve fibers. (
  • Discharge patterns of cat primary auditory fibers with electrical stimulation of the cochlea. (
  • Breast cancer growth and progression were accelerated following stimulation of sympathetic nerves in tumors, but were reduced following stimulation of parasympathetic nerves. (
  • Once the detailed intrinsic renal sympathetic innervation was more clearly understood, it was readily demonstrated in a variety of species that low-frequency renal sympathetic nerve stimulation, which did not affect renal blood flow or glomerular filtration rate, caused a reversible decrease in urinary sodium excretion. (
  • Quantitative sensory hand function and sensory conduction studies by near-nerve technique, including tactile stimulation of mechanoreceptors, were followed for 2 years, and results were compared to noninjured hands. (
  • Electrically evoked single-fiber action potentials from cat: responses to monopolar, monophasic stimulation. (
  • However, rigorous psychophysical and neurophysiological evidence for a functional role of A-fibers in the mediation of nonhistaminergic itch in primates is lacking. (
  • Rehabilitation is still required to make these new nerve fibers functional for walking. (
  • Group C nerve fibers are one of three classes of nerve fiber in the central nervous system (CNS) and peripheral nervous system (PNS). (
  • C fibers are unmyelinated unlike most other fibers in the nervous system. (
  • In the autonomic nervous system, fibers from the CNS to the ganglion are known as preganglionic fibers. (
  • Like other components of the sympathetic nervous system, all of these exceptions are still stimulated by cholinergic pre ganglionic fibers. (
  • Yet, injuries to the spinal cord lead to devastating conditions, since severed nerve fibers fail to regenerate in the central nervous system. (
  • There are nerve fibers in the central nervous system and peripheral nervous system. (
  • The nerve cells are located either in the receptor organ itself or in special sensory ganglia that are close to the central nervous system. (
  • The Nervous System The brain relays messages by way of the spinal cord through nerve fibers. (
  • This differentiated regulation occurs via mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. (
  • If it's about the same length and diameter as a neuron, the nerve cells follow it and their shape and location conform to it," he says. (
  • Essentially, these fibers are the same size as a neuron. (
  • The researcher started out by using a laser to sever nerves in a zebrafish's original tail fin, assuming that the nerves would regenerate-but they did not! (
  • Researchers have advanced a decades-old quest to get injured nerves to regenerate. (
  • Researchers at Children's Hospital Boston and Harvard Medical School have advanced a decades-old quest to get injured nerves to regenerate. (
  • What if it were possible to regenerate severed nerve fibers across spinal cord injury? (
  • In a collaboration led by EPFL (Ecole polytechnique fédérale de Lausanne) in Switzerland and UCLA (University of California at Los Angeles) in the USA, scientists have now understood the underlying biological mechanisms required for severed nerve fibers to regenerate across complete spinal cord injury, bridging that gap in mice and rats for the first time. (
  • He sees the pain, the loss of ability and the other effects that nerve-destroying conditions cause - and wishes he could give patients more effective treatments than what's available, or regenerate their nerves. (
  • Meanwhile, new fibers were also found to directly regenerate from deep in the stroma in some cases. (
  • Nerves radiate to every part of the body to provide connections for input and output data. (
  • While some of the afferent nerves consist of fibers from different receptors (for example, cutaneous and muscular), most nerves consist of fibers of a single sensory type. (
  • Researchers have discovered the main culprit for nerve fibre damage in. (
  • Researchers have discovered the main culprit for nerve fibre damage in multiple sclerosis, which is triggered by the body's own immune system, which is vital for early diagnosis // and evolving improved treatment of a severe disease. (
  • The present data provide direct evidence that 5-HT in the female reproductive system not only is associated with mast cells but is located in nerve fibre-like structures as well. (
  • The vagina is innervated by a complex arrangement of sensory, sympathetic, and parasympathetic nerve fibers that contain classical transmitters plus an array of neuropeptides and enzymes known to regulate diverse processes including blood flow and nociception. (
  • Fig. 7: Abundance of sympathetic and sparcity of parasympathetic nerve fibers in individuals with breast cancer with recurrence. (
  • The middle panel shows a nerve cell growing on the resulting mesh, which has a texture similar to the body's fibrous connective tissue. (
  • Synthetic neural scaffolds hold promise to eventually replace nerve autografts for tissue repair following peripheral nerve injury. (
  • All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are cholinergic (that is, these fibers use acetylcholine as their neurotransmitter) and they are myelinated. (
  • Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are often closer to the spinal cord than are the parasympathetic ganglia. (
  • In our visual system, the optic nerves normally combine at a place called the optic chiasm. (
  • The study involved the optic nerve, which connects nerve cells in the retina with visual centers in the brain, but the Children's team has already begun to extend the approach to nerves damaged by spinal cord injury, stroke, and certain neurodegenerative diseases. (
  • The sensory nerve action potentials (SNAPs) remained dispersed and areas recovered to 23 ± 2% and the amplitudes only to 7 ± 1% (P (
  • Cryofracture preparation of a sciatic nerve cross-section showing the myelin sheaths around nerve fibers. (
  • Paying heed to the importance of physical activity in neural plasticity, this study focuses on the investigation of chronic effect of decreased activity on the form of spinal nerve ligation on NT-4 gene expression of male Wistar rat's sciatic nerve fiber. (
  • At the end of the sixth week, the changes in NT-4 gene expression in sciatic nerve were measured with Real time technique. (
  • Damage or injury to nerve fibers causes neuropathic pain . (
  • In 2002, they reported that inosine helped stroke-impaired rats to regrow nerve connections between brain and spinal cord and partially recover motor function. (
  • In MS, the immune system damages and destroys myelin, the material that surrounds and protects nerve fibers in the brain and spinal cord. (
  • Assessment of the nerve fiber loss may be difficult by conventional photographs or ophthalmoscope. (
  • C fibers are one class of nerve fiber found in the nerves of the somatic sensory system . (
  • the process of demyelination interrupts electrical impulses that run through these nerve fibers, thus causing MS symptoms. (
  • Substance P-like immunoreactive nerve fibers in the trabecular meshwork. (
  • Localization of 5-hydroxytryptamine-like immunoreactive cells and nerve fibers in the rat female reproductive system. (
  • The occurrence of 5-HT-like immunoreactive (IR) nerve fibers has been demonstrated in the perivascular nerves of different vascular beds (Costa et al. (
  • The distal vagina also showed increased vascularization and perivascular fibers containing NPY. (
  • Sensation is essential for recovery after peripheral nerve injury. (
  • So, she went back to the drawing board and discovered that if she also used the laser to damage some skin cells in the tail fin, the nerves regenerated. (
  • Rieger and colleagues went on discover that the opposite is also true: when they used a cancer chemotherapy drug to damage skin cells in a zebrafish tail fin, it contributed to the degeneration of the fin's nerve fibers [2]. (
  • Based on these findings, Rieger wants to see whether similar processes may be going on in the hands and feet of cancer patients who struggle with painful nerve damage, called peripheral neuropathy, caused by certain chemotherapy drugs, including taxanes and platinum compounds. (
  • This study focuses on the use of Metanx® as the sole treatment for improving and reversing nerve damage in type 2 diabetic patients with peripheral neuropathy. (
  • A new study suggests smoking high-potency marijuana may cause damage to nerve fibers responsible for communication between the brain's two hemispheres. (
  • After bowel surgery, more than half of the patients suffer from irreparable nerve damage. (
  • New research presented Thursday, Nov. 29, at RSNA's 2018 Annual Meeting added to that focus, finding the sport may damage brain fibers in young football players. (
  • Basis for Nerve fiber Damage in Multiple Sclerosis Discovered ( Researchers have discovered the main cu. (
  • In new research published in several recent papers, Corey and his colleagues from the U-M Medical School, VAAAHS and the University of California, San Francisco report success in developing polymer nanofiber technologies for understanding how nerves form, why they don't reconnect after injury, and what can be done to prevent or slow damage. (
  • They've even managed to encourage the process of myelination - the formation of a protective coating that guards larger nerve fibers from damage. (
  • Parameters associated with vulnerability of nerve fibers to glaucomatous damage. (
  • It was our clinical impression that topographic variation of the optic disc is a factor for this variable susceptibility of nerve fiber to glaucomatous damage. (
  • In conclusion, macroscopic variation of the optic disc is an important parameter which affect vulnerability of nerve fiber to glaucomatous damage. (
  • A new methodology is of value in assessing the degree of glaucomatous nerve damage in clinical practice. (
  • How many rods and cones per ganglion cell and an optic fiber? (
  • For the presented study, we implemented and applied two methods to bridge areas of fiber crossings: (i) extrapolation of fiber points with cubic splines and (ii) following the most frequently occurring orientations in a defined neighborhood based on orientation distribution functions gained from 3D-PLI measurements (pliODFs). (
  • Applied to fiber crossings within a human hemisphere, reconstructed from 3D-PLI measurements at 64 microns in-pane resolution, both methods were demonstrated to sustain their initial tract direction throughout the crossing region. (
  • This thesis presents analysis methods and models for ENF data, with two main puroposes: to find early signs of diabetic neuropathy and to characterize how this condition changes the nerve fiber structure. (
  • The MRI results showed that the football players developed changes in the corpus callosum, a critically important band of nerve fibers that connects the two halves of the brain. (
  • Results confirmed their suspicions, revealing football players developed changes in the corpus callosum-central nerve fibers that connect the two halves of the brain. (
  • Thinner nerve fiber layer was associated with worse performance on memory, reasoning, and reaction time at baseline, and with a decline in each of these tests over time," she said. (
  • Optic disc examination included evaluation of qualitative changes like contour of the neuroretinal rim, presence of optic disc hemorrhages, appearance of nerve fiber layer (NFL) and optic disc color and quantitative morphometric analysis of optic nerve head e. (
  • In a comparison between patients with PD and healthy controls, there was significant parafoveal inner nuclear layer thinning, whereas other retinal layers, including the retinal nerve fiber layer, as well as total macular thicknesses were not different. (
  • The retinal nerve fiber layer was thinnest in the group that had hallucinations without dementia, followed by the group that had hallucinations with dementia, and the group that had no hallucinations and no dementia. (
  • The results indicate that retinal nerve fiber layer thinning may be related to visual hallucination in nondemented patients with PD. (
  • Visual defects of glaucoma have been associated with retinal nerve fiber layer (NFL) defects, which can be detected as color and texture difference compared to normal NFL using photographs of NFL. (
  • Chiasmal compression predominantly affects the crossing nerve fibers and inner retinal layer in the nasal hemiretina. (
  • Representation for retinal nerve fiber layer thicknesses in the four quadrants using Cirrus HD and Stratus OCT devices. (
  • When the optic disc was tilted or cyclotorted, inferior retinal nerve fiber layer was more easily affected than the superior one. (
  • Small size of the disc correlated significantly with multiple retinal nerve fiber layer defect (ref. 3), and large size of the disc correlated significantly with vulnerable papillo-macular bundle defect (ref. 4). (
  • Publications] Chihara E,Honda Y: 'Preservation of nerve fiber layer by retinal vessels in glaucoma. (
  • Publications] Chihara E,Chihara K: 'Opparent cleavage of the retinal nerve fiber layer in normal eyes with high myopia' Graefes Arch Clin Exp.Ophthalmol. (
  • Some fibers have only a thin layer of myelin and are called non-myelinated. (
  • Any of various elongated cells or threadlike structures, especially a muscle fiber or a nerve fiber. (
  • The C group fibers are unmyelinated and have a small diameter and low conduction velocity, whereas Groups A and B are myelinated. (
  • Because of their higher conduction velocity, Aδ fibers are responsible for the sensation of a quick shallow pain that is specific on one area, termed as first pain . (