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 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.
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.
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.
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.
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.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.
A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.
Renewal or physiological repair of damaged nerve tissue.
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.
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.
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.
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.
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 remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.
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.
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 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.
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.
Injuries to the PERIPHERAL NERVES.
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.
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.
Use of electric potential or currents to elicit biological responses.
Nerve fibers liberating catecholamines at a synapse after an impulse.
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.
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.
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.
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.
A thioester hydrolase which acts on esters formed between thiols such as DITHIOTHREITOL or GLUTATHIONE and the C-terminal glycine residue of UBIQUITIN.
Neuroglial cells of the peripheral nervous system which form the insulating myelin sheaths of peripheral axons.
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.
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)
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.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
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.
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.
Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.
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.
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.
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)
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.
An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.
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.
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.
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)
Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.
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.
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.
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)
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.
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.
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.
The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
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.
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.
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.
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.
Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.
Act of eliciting a response from a person or organism through physical contact.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
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.
Neurons which send impulses peripherally to activate muscles or secretory cells.
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
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)
Twelve pairs of nerves that carry general afferent, visceral afferent, special afferent, somatic efferent, and autonomic efferent fibers.
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 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)
Neurons which activate MUSCLE CELLS.
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.
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.
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.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
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.
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.
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.
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.
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.
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.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
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.
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 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 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.
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.
The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.
An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.
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.
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 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.
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 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)
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.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
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.
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).
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.
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.
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.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
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).
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.
Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.
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.
The sensation of cold, heat, coolness, and warmth as detected by THERMORECEPTORS.
Mice which carry mutant genes for neurologic defects or abnormalities.
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.
The minimum amount of stimulus energy necessary to elicit a sensory response.
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)
Elements of limited time intervals, contributing to particular results or situations.
A subgroup of TRP cation channels named after vanilloid receptor. They are very sensitive to TEMPERATURE and hot spicy food and CAPSAICIN. They have the TRP domain and ANKYRIN repeats. Selectivity for CALCIUM over SODIUM ranges from 3 to 100 fold.
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.
A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.
Nerve fibers liberating acetylcholine at the synapse after an impulse.
Refers to animals in the period of time just after birth.
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.
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.
Neural tracts connecting one part of the nervous system with another.
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)
Substances used to identify the location and to characterize the types of NEURAL PATHWAYS.
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.
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.
Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane.
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.
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.
A contactin subtype that is predominantly expressed in the CEREBELLUM; HIPPOCAMPUS; NEOCORTEX; and HYPOTHALAMUS.
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.
Amount of stimulation required before the sensation of pain is experienced.
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.
Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.
The 4th cranial nerve. The trochlear nerve carries the motor innervation of the superior oblique muscles of the eye.
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.
A protein-tyrosine kinase receptor that is specific for NERVE GROWTH FACTOR; NEUROTROPHIN 3; neurotrophin 4, neurotrophin 5. It plays a crucial role in pain sensation and thermoregulation in humans. Gene mutations that cause loss of receptor function are associated with CONGENITAL INSENSITIVITY TO PAIN WITH ANHIDROSIS, while gene rearrangements that activate the protein-tyrosine kinase function are associated with tumorigenesis.
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
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.
A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.
Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.
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)
A toxic compound, isolated from the Spanish fly or blistering beetle (Lytta (Cantharis) vesicatoria) and other insects. It is a potent and specific inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A). This compound can produce severe skin inflammation, and is extremely toxic if ingested orally.
Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.
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.
The shortest duration of an electrical stimulus where the threshold amplitude is twice the rheobase - the minimum required for eliciting an ACTION POTENTIAL at any time period. It is a measure of the excitability of nerve or muscle tissue, and is characteristic of types and/or condition of the nerve or muscle cells in the tissue.
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.
A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.
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.
Any of several BRASSICA species that are commonly called mustard. Brassica alba is white mustard, B. juncea is brown or Chinese mustard, and B. nigra is black, brown, or red mustard. The plant is grown both for mustard seed from which oil is extracted or used as SPICES, and for its greens used as VEGETABLES or ANIMAL FEED. There is no relationship to MUSTARD COMPOUNDS.
The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.
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.
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.
Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC
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.
The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A voltage-gated sodium channel subtype found widely expressed in neurons of the central and peripheral nervous systems. Defects in the SCN8A gene which codes for the alpha subunit of this sodium channel are associated with ATAXIA and cognitive deficits.
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.
Drugs that block nerve conduction when applied locally to nerve tissue in appropriate concentrations. They act on any part of the nervous system and on every type of nerve fiber. In contact with a nerve trunk, these anesthetics can cause both sensory and motor paralysis in the innervated area. Their action is completely reversible. (From Gilman AG, et. al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed) Nearly all local anesthetics act by reducing the tendency of voltage-dependent sodium channels to activate.
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)
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.
The semilunar-shaped ganglion containing the cells of origin of most of the sensory fibers of the trigeminal nerve. It is situated within the dural cleft on the cerebral surface of the petrous portion of the temporal bone and gives off the ophthalmic, maxillary, and part of the mandibular nerves.
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.
Disease or trauma involving a single peripheral nerve in isolation, or out of proportion to evidence of diffuse peripheral nerve dysfunction. Mononeuropathy multiplex refers to a condition characterized by multiple isolated nerve injuries. Mononeuropathies may result from a wide variety of causes, including ISCHEMIA; traumatic injury; compression; CONNECTIVE TISSUE DISEASES; CUMULATIVE TRAUMA DISORDERS; and other conditions.
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 range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
A single inner hair cell is innervated by numerous nerve fibers, whereas a single nerve fiber innervates many outer hair cells ... Inner hair cell nerve fibers are also very heavily myelinated, which is in contrast to the unmyelinated outer hair cell nerve ... fibers. The region of the basilar membrane supplying the inputs to a particular afferent nerve fibre can be considered to be ... Neurons of the auditory or vestibulocochlear nerve (the eighth cranial nerve) innervate cochlear and vestibular hair cells. The ...
Different sensory receptors are innervated by different types of nerve fibers. Proprioceptors are innervated by type Ia, Ib and ... they send impulses faster than unmyelinated C fibers, but more slowly than other, more thickly myelinated group A nerve fibers ... Type Aβ fibres, and type Aγ, are the type II afferent fibers from stretch receptors. Type Aβ fibres from the skin are mostly ... Group A nerve fibers are one of the three classes of nerve fiber as generally classified by Erlanger and Gasser. The other two ...
... l tissues are frequently innervated by sensory nerve endings. These include myelinated as well as unmyelinated nerves. ... These collagen fibers are produced by fibroblasts located within the fascia. Fasciae are similar to ligaments and tendons as ... This fascia has a high density of elastin fibre that determines its extensibility or resilience. Deep fascia was originally ... It serves as a storage medium of fat and water; as a passageway for lymph, nerve and blood vessels; and as a protective padding ...
Postganglionic nerve fibers from the deep petrosal nerve join with preganglionic nerve fibers from the greater petrosal nerve ... The sense of smell is transmitted by the olfactory nerves. Olfactory nerves are bundles of very small unmyelinated axons that ... As are all of the facial muscles, the muscles of the nose are innervated by the facial nerve and its branches. Although each ... Sympathetic postganglionic fibers are distributed to the blood vessels of the nose. Postganglionic parasympathetic fibres ...
Each type I axon innervates only a single inner hair cell, but each inner hair cell is innervated by up to 30 such nerve fibers ... Ear anatomy Cochlear nucleus innervated by a branching auditory nerve fibre Terminal nuclei of the vestibular nerve, with their ... They have relatively small diameters, are unipolar, and are unmyelinated. In mammals, the axons from each cochlear nerve ... In humans, there are on average 30,000 nerve fibers within the cochlear nerve. The number of fibers varies significantly across ...
Sensory nerve fibers that originate from inferior and superior alveolar nerves innervate the odontoblastic layer of the pulp ... commonly associated with dentine hypersensitivity Unmyelinated C-Fibres: They are mainly located at the core of the pulp, and ... The dental pulp nerve is innervated by one of the Trigeminal nerves, otherwise known as the fifth cranial nerve. The neurons ... There are two types of nerve fiber that mediate the sensation of pain: A-fibers conduct rapid and sharp pain sensations and ...
... the capsaicin de-polarizes the nerve fibers, allowing sodium and calcium into the fibers. In order for fibers to do so, they ... In the mammalian peripheral nervous system, warmth receptors are thought to be unmyelinated C-fibres (low conduction velocity ... "Warm fibers innervating palmar and digital skin of the monkey: responses to thermal stimuli". Journal of Neurophysiology. 42 (5 ... while those responding to cold have both C-fibers and thinly myelinated A delta fibers (faster conduction velocity). The ...
CT neurons belong to a group C nerve fibers; these are unmyelinated, and have slow conduction velocities. CT afferents were ... "Mechanical allodynia in human glabrous skin mediated by low-threshold cutaneous mechanoreceptors with unmyelinated fibres". ... C tactile (CT) neurons are a class of low-threshold C neurons that innervate the human skin. In animals, these neurons are ... Nagi, Saad S.; Mahns, David A. (May 2013). "C-tactile Fibers Contribute to Cutaneous Allodynia After Eccentric Exercise". The ...
... group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. These groups ... or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in ... Lower motor neurons have two kind of fibers: Different sensory receptors innervate different types of nerve fibers. ... Nerve fibers are classed into three types - group A nerve fibers, ...
Because fibers are mixed in most nerves, it is usually essential to record from an individual nerve fiber at a time to explore ... be it multi-unit sympathetic activity or single unit activity of either a myelinated afferent or a small unmyelinated fibres. ... They are mechano-insensitive, low in number, and innervate small receptive fields. Aδ fibers are responsible for cold detection ... Nerve fibers (axons) of various kinds are more or less randomly mixed in most nerves. This is true for fibers of different ...
... innervated with sensory nerve fibres via the ophthalmic division of the trigeminal nerve by way of 70-80 long ciliary nerves. ... The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an ... Corneal stroma (also substantia propria): a thick, transparent middle layer, consisting of regularly arranged collagen fibers ... The ciliary nerves run under the endothelium and exit the eye through holes in the sclera apart from the optic nerve (which ...
... in unmyelinated fibres has been found in clusters associated with lipid rafts along DRG fibers both in vitro and in vivo ... Nerve growth factor levels in inflamed or injured tissues are increased creating an increased sensitivity to pain (hyperalgesia ... NaV1.8 and NaV1.9 in a distinct population of dorsal root ganglia innervating the rat knee joint in a model of chronic ... In myelinated fibres, VGSCs are located at the nodes of Ranvier; however, in unmyelinated fibres, the exact location of VGSCs ...
There are far fewer inner hair cells in the cochlea than afferent nerve fibers - many auditory nerve fibers innervate each hair ... unmyelinated) reciprocal communicative bundles (30+ hairs per nerve fiber); this contrasts inner hair cells (IHC) that have ... or cranial nerve number VIII. The region of the basilar membrane supplying the inputs to a particular afferent nerve fibre can ... Cochlear nerve fibers (30,000+) each have a most sensitive frequency and respond over a wide range of levels. Simplified, nerve ...
... stimulation of sensory nerve cells called nociceptors produces a signal that travels along a chain of nerve fibers via the ... After nerve injury it is possible for touch fibres that normally carry non-noxious stimuli to be perceived as noxious. ... Lamina 2 makes up substantia gelatinosa of Rolando, unmyelinated spinal grey matter. Substantia receives input from nucleus ... Illich, P. A.; Walters, E. T. (1997). "Mechanosensory neurons innervating Aplysia siphon encode noxious stimuli and display ...
... the MOCS contains myelinated nerve fibres which innervate the outer hair cells directly. Although both the LOCS and MOCS ... The LOCS (originating from both the intrinsic and shell neurons) contains unmyelinated fibres that synapse with the dendrites ... 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 ...
In the mammalian peripheral nervous system, warmth receptors are thought to be unmyelinated C-fibres (low conduction velocity ... Darian-Smith, Ian; Johnson KO; LaMotte C; Shigenaga Y; Kenins P; Champness P (1979). "Warm fibers innervating palmar and ... The nerve endings of sensory neurons that respond preferentially to cooling are found in moderate density in the skin but also ... while those responding to cold have both C-fibers and thinly myelinated A delta fibers (faster conduction velocity).[1] The ...
A single inner hair cell is innervated by numerous nerve fibers, whereas a single nerve fiber innervates many outer hair cells ... Inner hair cell nerve fibers are also very heavily myelinated, which is in contrast to the unmyelinated outer hair cell nerve ... fibers. The region of the basilar membrane supplying the inputs to a particular afferent nerve fibre can be considered to be ... Neurons of the auditory or vestibulocochlear nerve (the eighth cranial nerve) innervate cochlear and vestibular hair cells. The ...
Muscle fibres explanation free. What is Muscle fibres? Meaning of Muscle fibres medical term. What does Muscle fibres mean? ... Looking for online definition of Muscle fibres in the Medical Dictionary? ... unmyelinated fs nerve fibers that lack a myelin sheath; see myelin.. visceral fs (visceral nerve fs) nerve fibers, afferent ... gamma fs fibers that conduct touch and pressure impulses and innervate the intrafusal fibers of the muscle spindle; they ...
Su, X., Gebhart, G. F. Mechanosensitive pelvic nerve afferent fibers innervating the colon of the rat are polymodal in ... Habler, H. J., Janig, W., Koltzenburg, M. Activation of unmyelinated afferent fibres by mechanical stimuli and inflammation of ... Sengupta, J. N., Gebhart, G. F. Mechanosensitive properties of pelvic nerve afferent fibers innervating the urinary bladder of ... Sengupta, J. N., Gebhart, G. F. Characterization of mechanosensitive pelvic nerve afferent fibers innervating the colon of the ...
Different sensory receptors are innervated by different types of nerve fibers. Proprioceptors are innervated by type Ia, Ib and ... they send impulses faster than unmyelinated C fibers, but more slowly than other, more thickly myelinated group A nerve fibers ... Type Aβ fibres, and type Aγ, are the type II afferent fibers from stretch receptors. Type Aβ fibres from the skin are mostly ... Group A nerve fibers are one of the three classes of nerve fiber as generally classified by Erlanger and Gasser. The other two ...
Conduction velocity is regulated by sodium channel inactivation in unmyelinated axons innervating the rat cranial meninges. ... Sun, W., et al. Reduced conduction failure of the main axon of polymodal nociceptive C-fibres contributes to painful diabetic ... Zhu, Z. R., et al. Modulation of action potential trains in rabbit saphenous nerve unmyelinated fibers. Neurosignals. 21, (3-4 ... Zhu, Z. R., et al. Conduction failures in rabbit saphenous nerve unmyelinated fibers. Neurosignals. 17, (3), 181-195 (2009). ...
5-Hydroxytryptamine2C receptors on pudendal motoneurons innervating the external anal sphincter. Holmes, G. M., Sep 28 2005, In ... 5-Hydroxytryptamine selectively activates the vagal nodose C-fibre subtype in the guinea-pig oesophagus. Yu, S., Ru, F., Ouyang ...
Encoding of burning pain from capsaicin-treated human skin in two categories of unmyelinated nerve fibres. Brain. 2000;123(pt 3 ... B) Most nociceptors are unmyelinated with small diameter axons (C-fibers, red). Their peripheral afferent innervates the skin ( ... Minimally invasive extracellular single unit recordings from nerve fibers in peripheral nerves (microneurography) and skin- ... A-fibers lose their myelin sheath and the unmyelinated A-fiber branches cluster in separated small spots within a small area, ...
... categorized as C fibers, are present in skin, peripheral nerves, and organs. The role of these nerves is to innervate the skin ... Small fiber peripheral neuropathy is a type of peripheral neuropathy that occurs from damage to the small unmyelinated ... Autonomic nerve fibres are affected in most symmetrical peripheral neuropathies; however, involvement is often subclinical or ... Peripheral nerves refer to all the nerves in the body outside the brain and spinal cord. A neuropathy is any disease process ...
Each type I axon innervates only a single inner hair cell, but each inner hair cell is innervated by up to 30 such nerve fibers ... They have relatively small diameters, are unipolar, and are unmyelinated.. Cochlear nuclear complex[edit]. In mammals, the ... In humans, there are on average 30,000 nerve fibers within the cochlear nerve.[1] The number of fibers varies significantly ... The cochlear nerve (also auditory or acoustic neuron) is one of two parts of the vestibulocochlear nerve, a cranial nerve ...
C-fibers are unmyelinated nerve fibres that transmit large threshold mechanical, thermal, and chemical signals that are ... nerve trunks enter the corneal stroma radially and ascend to innervate the corneal epithelium as free of charge nerve endings ... C-fibers are unmyelinated nerve fibres that transmit large threshold mechanical, thermal, and chemical signals that are ... Unlike somatic nerve innervation, the cornea lacks A-beta fibers, and fibers involved in autonomic function are sparsely ...
2009 Conduction failures in rabbit saphenous nerve unmyelinated fibers. Neurosignals 17, 181-195. doi:10.1159/000209279 (doi: ... 1999 Activity-dependent slowing of conduction differentiates functional subtypes of C fibres innervating human skin. J. Physiol ... 1987 Na currents and action potentials in rat myelinated nerve fibres at 20 and 37 degrees C. Pflugers Arch. 409, 569-577. doi: ... Axonal coding of action potentials in demyelinated nerve fibers. Brain Res. 619, 278-290. doi:10.1016/0006-8993(93)91622-Y (doi ...
... conduction velocity of myelinated fibers in the radial nerve was 16.1 m/s faster than myelinated fibers in the peroneal nerve. ... Myelinated afferent fibres innervating the primate skin and their response to noxious stimuli. J. Physiol. 197, 593-615 (1968). ... Unmyelinated tactile afferents underpin detection of low-force monofilaments. Muscle Nerve 34, 105-107 (2006).. ... In comparison to the peroneal nerve, conduction velocities of A-fiber types were faster in the radial nerve as expected (A-HTMR ...
2000) Encoding of burning pain from capsaicin-treated human skin in two categories of unmyelinated nerve fibres. Brain 123:560- ... 1999) Activity-dependent slowing of conduction differentiates functional subtypes of C fibres innervating human skin. J Physiol ... frog A-fiber, ∼500 msec; human Aβ-fiber, 15-20 msec; human Aα-fiber, 4 sec; human C-fiber, ∼500 msec); (4) the hypoexcitable ... 1979) Effects of nerve impulses on threshold of frog sciatic nerve fibres. J Physiol Lond 290:273-303. ...
Free nerve ending terminal morphology is fiber type specific for A∂ and C fibers innervating rabbit corneal epithelium. J ... Gallar J, Pozo MA, Tuckett RP, Belmonte C. Response of sensory units with unmyelinated fibres to mechanical, thermal and ... whereas C fibers are small-diameter, beaded nerves that respond to thermal and chemical stimuli. 5 6 7 8 9 The nerves can also ... From this basal cell layer plexus, nerve fibers ramify anteriorly toward the epithelial surface. The fibers are of two main ...
Fascial tissues are frequently innervated by sensory nerve endings. These include myelinated as well as unmyelinated nerves. ... This fascia has a high density of elastin fibre that determines its extensibility or resilience.[10] Deep fascia was originally ... These collagen fibers are produced by fibroblasts located within the fascia.[1] ... It serves as a storage medium of fat and water; as a passageway for lymph, nerve and blood vessels; and as a protective padding ...
axons emerge as part of a cranial nerve or as part of anterior root of a spinal nerve. - cranial parasympathetic outflow ... postganglionic autonomic fibers do not end in a single terminal swelling like a synaptic knob or end plate. - terminal branches ... cell body is in the brain or spinal cord, and its axon exits the CNS as is a small-diameter, myelinated fibres that usually ... unmyelinated postganglionic axons from lumbar and sacral sympathetic trunk ganglia enter a short pathway called gray rams and ...
Find out information about cutaneous nerve of calf, lateral. see nervous system nervous system, network of specialized tissue ... that controls actions and reactions of the body and its adjustment to the environment.... Explanation of cutaneous nerve of ... fibers; others, for example, the sympathetic nerves, largely consist of unmyelinated, or unmedullated, fibers. ... nerve. 1. any of the cordlike bundles of fibres that conduct sensory or motor impulses between the brain or spinal cord and ...
... and hairy skin lend support for an underlying system of innocuous mechanoreception with Cav3.2-expressing unmyelinated fibres. ... Afferent nerve responses were acquired from 58 slowly-adapting (SA) type-I and 25 fast-adapting (FA) type-I isolated single ... This is the first study to demonstrate this, using spike trains recorded from tactile afferents innervating the monkey ... The Bayesian Decoding of Force Stimuli from Slowly Adapting Type I Fibers in Humans.. ...
Pyramidal fibres are comparatively slow conducting , because at least half of the pyramidal tract fibers are unmyelinated . ... These are the neurons of the motor nuclei of the cranial nerves and anterior motor neurons in the spinal cord, their axons, and ... the muscles innervated by them. *Motor Cortex ( Cortical Motor Areas) *The motor cortex lies anterior to the central sulcus and ... But most of pyramidal fibers are unmyelinated *Fibers from the cerebral cortex descend in corona radiatato reach the internal ...
Results The human dental pulp can be abundantly innervated through unmyelinated neural materials and also in the past a lot of ... had been consideration to derive from initial AZD-8055 associated with modest size nerves that will generally produce c-fibers ... Last but not least, your detection regarding NaCh accumulations within unmyelinated fibres had been unexpected and contains ... specific NaCh examine and also the conclusions presented below offer further evidence for living throughout unmyelinated fibres ...
Distribution of Unmyelinated Primary Afferent Fibers in the Dorsal Horn Y. Sugiura, N. Terui, Y. Hosoya, K. Kohno ... Laminar and Segmental Termination in the Dorsal Horn of the Spinal Cord of an Articular Nerve of the Forepaw in the Cat ... Cell Size and Nissl Pattern Analyses of Primary Afferent Neurons Innervating the Molar Tooth Pulp and Cornea of the Rat ... Denervation Induced Changes in Somatotopic Organization: The Ineffective Projections of Afferent Fibres and Structural ...
... unmyelinated nerve fibers present in the functional layer of endometrium, and these nerve fibers are also greatly increased in ... "Blood vessels are innervated by sensory and sympathetic fibres; thus when blood vessels branch to vascularise developing ... Women without endometriosis almost never have these nerve fibers. These nerve fibers may also play a role in pain generation." ... nerve supply. The supply is derived from nerve fibers innervating nearby territories that sprout branches into the growths [10] ...
Bladder sensation is coordinated by primary afferent sensory neurons that innervate the bladder wall, translating bladder ... Bladder sensation is coordinated by primary afferent sensory neurons that innervate the bladder wall, translating bladder ... Pelvic afferents, isolated from nerve fibres between the pelvic ganglia and the spinal cord, were dissected into fine multiunit ... Habler, H. J., Janig, W., and Koltzenburg, M. (1990). Activation of unmyelinated afferent fibres by mechanical stimuli and ...
... housed in dorsal main ganglia and sensory nerve terminals of unmyelinated C-fibers or thinly myelinated A-fibers that innervate ... Immunofluorescence staining demonstrated that TRPV1-positive nerve fibres situated in the renal cortex, medulla, and pelvis, ... Following the renal nerve activity was confirmed which consists of pulse synchronous rhythmicity using the heartbeat, the nerve ... and ureter are seriously innervated by TRPV1-positive sensory nerves located between your layers of soft muscle groups and ...
What is nerve fiber? Meaning of nerve fiber as a legal term. What does nerve fiber mean in law? ... Definition of nerve fiber in the Legal Dictionary - by Free online English dictionary and encyclopedia. ... Ultrastructure of the myelinated and unmyelinated nerve fibers of the tongue mucosa of albinus rat (Wistar) with aging / ... The cornea is the most densely innervated tissue in the body, so corneal nerve assessment is extremely sensitive for detecting ...
Unmyelinated neurones postganglionic fibres and some elastic fibres, which increase and helper t - cells ige found on the cuff ... Surrounding the axons leave this nerve and its associated moment arm, the posterior fibers gluteus minimus inferior gluteal ... uses two suture anchors have achieved functional arthroplasties with an open shift control model in which it innervates the ... The plantar nerves plantar flexion occur by one type of immunity is emphasised in situations where the obstruction air is ...
Neuropathy, Small Fibre Small Fiber Neuropathies Small Fibre Neuropathies Small Fibre Neuropathy Small Nerve Fiber Neuropathy ... see A FIBERS) and unmyelinated C FIBERS. Because these small fibers innervate skin and help control autonomic function, their ... The affected small nerve fibers include myelinated A-delta fibers (see A FIBERS) and unmyelinated C FIBERS. Because these small ... Neuropathy, Small Fibre. Small Fiber Neuropathies. Small Fibre Neuropathies. Small Fibre Neuropathy. Small Nerve Fiber ...
... quantitative sensory testing of A-delta and C-fibre function using cold and warm stimuli was used to assess which nerve fibre ... Also A-delta fibres have been implicated in the static subtype. A low intensity vertically applied stimulus of 1 second (s) is ... In patients with SMA we assumed an activation of Cbut also A-delta fibres from a static 10 s von Frey filament stimulus. The ... Conclusions These findings support the role of A-beta fibres as peripheral mediators of both vF1 and vF10 although different ...
... the description of having unmyelinated C fibers with free nerve endings Genital corpuscles are innervated by myelinated fibers ... Low threshold mechanoreceptors and nociceptive units with unmyelinated (C) fibres in the human supraorbital nerve. J. Physiol. ... NFM / IB4+ GPAs most definitely have unmyelinated C fibers with free nerve endings, since IB4 has been shown by Petruska et al ... Mechanosensitive properties of pelvic nerve afferent fibers innervating the urinary bladder of the rat J. Neurophysiol. 72(5), ...
Slow chronic (dull-aching or burning) pain is mediated by nociceptors innervated by group C thin unmyelinated nerve fibers that ... The main part of each hair fibre is the cortex, which is composed of keratinized spindle-shaped cells. Terminal hair (as that ... The skin is innervated with around one million afferent nerve fibers. Most terminate in the face and extremities; relatively ... Fast sharp (pricking) pain is mediated by nociceptors innervated by group A delta thick myelinated nerve fibers which transmit ...
  • Diabetic neuropathy affects all peripheral nerves including sensory neurons, motor neurons, but rarely affects the autonomic nervous system. (
  • Type I neurons make up 90-95% of the neurons and innervate the inner hair cells. (
  • Type II neurons make up the remaining 5-10% of the neurons and innervate the outer hair cells. (
  • These are the neurons of the motor nuclei of the cranial nerves and anterior motor neurons in the spinal cord, their axons, and the muscles innervated by them. (
  • Bladder sensation is coordinated by primary afferent sensory neurons that innervate the bladder wall, translating bladder stretch into signals that travel to the brain via the spinal cord. (
  • TRPV1 stations are primarily portrayed in sensory neurons housed in dorsal main ganglia and sensory nerve terminals of unmyelinated C-fibers or thinly myelinated A-fibers that innervate several organs/tissues like the lung, center, kidney, and bloodstream vessel (3C9). (
  • Of most relevance to the direct generation of perceivable sensations, including pain, are the extrinsic sensory afferent neurons innervating the colon and rectum via the spinal nerves. (
  • In certain sensory neurons ( pseudounipolar neurons ), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body, and from the cell body to the spinal cord along another branch of the same axon. (
  • Single and dual retrograde neuronal tracing from the airways and esophagus revealed that distinct, but intermingled, subsets of neurons in the compact formation of the nucleus ambiguus (nAmb) innervate these two tissues. (
  • The relaxant preganglionic neurons can also be differentiated from the vagal motor neurons that innervate the esophageal striated muscle. (
  • Electrical stimulation of the vagi produces both cholinergic contractile and non-adrenergic non-cholinergic relaxant responses which are mediated via distinct parasympathetic postganglionic neurons innervating the airway smooth muscle (reviewed in Mazzone and Canning, 2002a ). (
  • Understanding these regulatory mechanisms is especially important because dysfunction of the corneal sensory nerves 7 - 10 and of the neurons in the central nervous system 11 involved in basic tearing has been hypothesized to contribute to the pathogenesis of DED. (
  • 1 h, demonstrating that prolonged input into the medulla during stimulation of somatic nerves, depending on the degree of convergence, leads to more or less inhibition of activity of these cardiovascular neurons. (
  • In a similar manner, sympathetic cardiovascular rVLM neurons that respond to both visceral (reflex) and somatic (EA) nerve stimulation manifest graded responses during stimulation of specific acupoints, suggesting that this medullary region plays a role in site-specific inhibition of cardiovascular reflex responses by acupuncture. (
  • In this respect preganglionic autonomic motor neurons are clearly distinguished from somatic motor neurons that project from the CNS directly to the innervated tissue (skeletal muscle), without any intervening ganglia. (
  • Post-ganglionic axonal processes of motor neurons in the autonomic ganglia innervate organs and tissues throughout the body (eyes, salivary glands, heart, stomach, urinary bladder, blood vessels, etc). (
  • The nerve endings of sensory neurons that respond preferentially to cooling are found in moderate density in the skin but also occur in relatively high spatial density in facial skin, cornea, tongue and strangely enough the bladder. (
  • The aim of the present study was to characterize the acid-evoked currents in DRG neurons that innervate the descending colon in the mouse. (
  • Because electrophysiological and mechanosensory properties as well as the receptive fields of afferent fibers innervating the colon differ between these two pathways ( 7 , 17 ), we examined differences in acid-sensitive currents in TL and LS DRG neurons innervating the mouse colon. (
  • It is mediated by high threshold unmyelinated C-fibers or thinly myelinated A-delta fibers whose primary neurons reside in the dorsal root ganglion. (
  • In spite of that, it is well recognized that visceral hypersensitivity can occur due to (1) sensitization of primary sensory afferents innervating the viscera, (2) hyperexcitability of spinal ascending neurons (central sensitization) receiving synaptic input from the viscera, and (3) dysregulation of descending pathways that modulate spinal nociceptive transmission. (
  • Neurons transmit nerve impulses to and from the central nervous system (CNS), thereby integrating motor and sensory functions. (
  • The dorsal root is a collection of the sensory neurons for that given peripheral nerve and can contain hundreds of thousands of neurons. (
  • It is formed of cell-bodies, non-medullated nerve fibres, neuroglea, dendrites of association neurons and motor neurons. (
  • It is formed of medullated nerve fibres or myelinated axon of motor and sensory neurons, which appear white due to presence of medullary sheath. (
  • B f's myelinated preganglionic autonomic axons having a fiber diameter less than 3 μm and a conduction velocity of 3 to 15 meters per second. (
  • Their cell bodies are located in the dorsal root ganglia and axons are sent to the periphery to innervate target organs and are also sent through the dorsal roots to the spinal cord. (
  • The peripheral axons of auditory nerve fibers form synaptic connections with the hair cells of the cochlea via ribbon synapses using the neurotransmitter glutamate . (
  • These central axons exit the cochlea at its base and form a nerve trunk , which, in humans, is approximately one inch long. (
  • In mammals, the axons from each cochlear nerve terminate in the cochlear nuclear complex that is ipsilaterally located in the medulla of the brainstem. (
  • 1 The trunks contain 900 to 1200 myelinated and unmyelinated axons (diameter 0.5-5 μm), and these ramify to produce a poorly characterized plexus beneath Bowman's layer. (
  • Last but not least, your detection regarding NaCh accumulations within unmyelinated fibres had been unexpected and contains extensive implications linked not just in axonal excitability, and also the intrinsic potential involving axons to be able to bunch NaChs even without molecular hints coming from myelinating glial cellular material. (
  • Surrounding the axons leave this nerve and its associated moment arm, the posterior fibers gluteus minimus inferior gluteal nerve to achieve some degree of posterior subluxation as sequelae of neonatal mortality an analysis suggests that a digital synovial sheath. (
  • 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). (
  • The cutaneous nerves contain axons with cell bodies in the dorsal root ganglia. (
  • These signals are transmitted from the peripheral terminals of extrinsic sensory nerve fibers, located within the wall of the colon or rectum, and via their axons within the spinal splanchnic and pelvic nerves to the spinal cord. (
  • The optic nerve is actually a nerve tract of axons that originate in the ganglion cells of the retina in the back of the eye. (
  • In the US of the PCBMN there were on average 620 (SD 220) myelinated axons, 80% of them smaller than 40 microm(2) i.e. thin myelinated axons, and on average 2037 (SD 1106) unmyelinated axons, arranged in 1-3 fascicles. (
  • Frequency distribution of cross-sectional areas of myelinated axons shows no significant difference between the US and the main nerve trunk of thePCBMN. (
  • the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. (
  • Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. (
  • Our findings suggest that carpal tunnel syndrome does not exclusively affect large fibres but is associated with loss of function in modalities mediated by both unmyelinated and myelinated sensory axons. (
  • DCN FCs integrate the acoustic information from AN fibers with MS signals transmitted via granule cell axons (parallel fibers) ( 17 ⇓ - 19 ). (
  • DCN granule cells and their parallel fiber axons represent a site of integration of multimodal sensory inputs such as the trigeminal ganglion ( 20 ), the spinal trigeminal nucleus ( 21 ), the pontine nucleus ( 22 ), the cuneate nucleus, the gracile nuclei ( 23 , 24 ), and the raphe nucleus ( 25 ). (
  • In the mammalian peripheral nervous system warmth receptors are thought to be unmyelinated C-fibres (low conduction velocity), while those responding to cold have thinly myelinated Aδ axons (faster conduction velocity). (
  • Peripheral nerves contain fascicles of nerve fibers consisting of axons. (
  • In peripheral nerve fibers, axons are ensheathed by Schwann cells, which may or may not form myelin around the axons, depending on their diameter. (
  • Nerve = bundle of axons (nerve fibers) with! (
  • Proprioceptors are innervated by type Ia, Ib and II sensory fibers, mechanoreceptors by type II and III sensory fibers, and nociceptors and thermoreceptors by type III and IV sensory fibers. (
  • However a small fraction of these fast fibres also transmit pain Type Aδ fibers are the afferent fibers of nociceptors. (
  • Here, we review the nociceptive aspect of pain perception, focusing on nociceptors innervating the skin and subserving exteroception of noxious stimuli. (
  • 1. Mechano‐ and heat‐sensitive A fibre nociceptors (AMHs) and C fibre nociceptors (CMHs) in hairy skin (forty‐six AMHs and twenty‐one CMHs) and in glabrous skin (fifty‐nine AMHs and ten CMHs) of anaesthetized monkeys were tested with a 30 s, 53 degrees C heat stimulus, delivered by a laser thermal stimulator (0.1 s rise time, 7.5 mm diameter). (
  • 4. C fibre nociceptors in hairy skin had a peak discharge near stimulus onset, a mean response latency of 100 ms and a median heat threshold of 41 degrees C. Heat responses of CMHs in glabrous skin were not significantly different from those in hairy skin. (
  • Both Aδ- and C-fibers possess nociceptors [3] [4] , and can respond to noxious stimuli of mechanical, thermal, and chemical characteristics. (
  • Several years ago, we developed simple methods for differentiating pain or responses evoked by the activation of A-delta or C fiber nociceptors in humans and animals. (
  • Acupuncture also stimulates the nervous system by activating nociceptors, sensory nerves and proprioceptor fibers that travel from the skin to the spine and from the spine to the brain. (
  • Since recent reviews have described in detail the molecules involved in detecting noxious stimuli ( 10 - 13 ) and contributing to protective mechanisms mediating enhanced pain at the site of injury ( 14 ), we take an integrative approach that highlights recently discovered cellular transduction/conduction mechanisms in the context of different nociceptor fiber types identified in vivo and ex vivo. (
  • While variations in dietary fiber denseness across different body sites might donate to adjustable level of sensitivity to stimuli, the overriding queries are: If little fibers are influenced by a disease, will there be AMG-176 widespread dietary fiber modification also? (
  • Sensitized C-fibers tend to be more attentive to suprathreshold mechanised stimuli vs. (
  • A compression/ischemia-induced (differential) nerve block in conjunction with repeated quantitative sensory testing of A-delta and C-fibre function using cold and warm stimuli was used to assess which nerve fibre population that contributes to pain at perception threshold level using 1 s (vF1) and 10 s (vF10) von Frey filament stimulation of the skin. (
  • Optic neuritis is an inflammation that affects the myelin lining of the optic nerve, which transmits visual stimuli to the brain. (
  • Somatosensory receptors develop in the various parts of the body to enable detection and reception of stimuli which is then transmitted through the nerve fibers to the central nervous system (Nakamura & Morrison, 2008). (
  • Response of cutaneous sensory units with unmyelinated fibers to noxious stimuli. (
  • 1025 - 1043 1969 Bessou P Perl ER: Response of cutaneous sensory units with unmyelinated fibers to noxious stimuli. (
  • C-fibres would be the most common type and are slow to conduct and respond to stimuli. (
  • This is the fifth of twelve pairs of cranial nerves that are responsible for transmitting numerous motor, sensory, and autonomous stimuli to structures of the head and neck . (
  • It is a purely sensory nerve that carries afferent stimuli of pain , light touch , and temperature from the upper eyelids and supraorbital region of the face, up to the vertex of the head. (
  • We are also using a combination of cortical evoked potential responses to laser pulsed pain stimuli as well as functional magnetic resonance imaging (fMRI) of the brain of volunteers (and eventually patients) to determine the cortical representation of these A-delta and C fiber mediated pain. (
  • With the arrival AMG-176 of laser scanning in vivo confocal microscopy performed in the human being cornea, small-fiber afferents can now become imaged noninvasively and at high spatial resolution. (
  • Unitary recordings were made from 15 muscle spindle afferents supplying TA via a microelectrode inserted into the common peroneal nerve. (
  • DNP reflex afferents also were bilaterally presynaptically inhibited segmentally by other DNP afferents, particularly by myelinated fibers. (
  • SP-immunoreactive glans afferents not connected to the BSM circuitry, compared to those that were, tended to be the smallest/unmyelinated population. (
  • In addition, putative unmyelinated urethral afferents that are synaptically connected to the BSM circuitry were larger compared to those of glans afferents. (
  • for example, promoting the sparing of at least one side of the cord, or harnessing the sprouting ability of Ad or C fiber afferents involved in the pudendal reflex. (
  • Extrinsic sensory afferents that innervate the colon and rectum are subdivided based on the location of their soma. (
  • Splanchnic nerve cell bodies are located within the thoracolumbar dorsal root ganglia (DRG), whilst pelvic afferents have cell bodies within the lumbosacral DRG ( Grundy and Brierley, 2018 ). (
  • To investigate the role of small myelinated afferents in nonhistaminergic itch, we tested, in psychophysical studies in humans, the effect of a differential nerve block on itch produced by intradermal insertion of spicules from the pods of a cowhage plant ( Mucuna pruriens ). (
  • These findings demonstrate that activity in nociceptive, myelinated afferents contributes to cowhage-induced sensations, and that nonhistaminergic itch is mediated through activity in both unmyelinated and myelinated afferents. (
  • In electrophysiological recordings from primary afferents in the anesthetized monkey, we tested whether cowhage, histamine, or capsaicin activated high threshold A-fiber afferents. (
  • Evidence for two different heat transduction mechanisms in nociceptive primary afferents innervating monkey skin. (
  • Fingerprint Dive into the research topics of 'Evidence for two different heat transduction mechanisms in nociceptive primary afferents innervating monkey skin. (
  • Aldskogius H, Elfvin LG, Forsman CA (1986) Primary sensory afferents in the inferior mesenteric ganglion and related nerves of the guinea pig. (
  • 5 , 6 The identification of substrates underpinning the sensitisation of sensory afferents innervating the OA joint may provide new targets for treatments which prevent, or delay, the progression of OA pain. (
  • Each of the ISOs (roughly 4000 in A. mississippiensis and 9000 in C. niloticus ) was innervated by networks of afferents supplying multiple different mechanoreceptors. (
  • adrenergic f's nerve fibers of the sympathetic nervous system that liberate norepinephrine (and possibly small amounts of epinephrine ) at a synapse when a nerve impulse passes. (
  • Our group discovered that ectopic growths harvested from ENDO rats and women with established endometriosis develop their own C-fiber (sensory afferent) and sympathetic (autonomic efferent) nerve supply. (
  • Our findings strongly support the hypothesis that the invasion of the cysts by sensory and sympathetic fibers is a major contributor to the development of endometriosis-associated pain, which suggests an aggressive clinical strategy of prevention. (
  • Reporting the range of motion, comfort, and satisfaction were better for idiopathic adhesive capsulitis and 2order levitra reex sympathetic dystrophy spinal accessory nerve injury. (
  • Activation of TRPV1 portrayed in sensory nerves qualified prospects to the discharge of sensory neuropeptides including element P (SP) and calcitonin gene-related peptide (CGRP), and SP eventually activates the neurokinin 1 (NK1) receptors situated in sensory nerves leading to a rise in afferent renal nerve activity (ARNA) that could inhibit contralateral sympathetic nerve activity (represent activation and depict suppression. (
  • In the sympathetic nervous system, postganglionic fibres are adrenergic , unlike those in the parasympathetic system, which are cholinergic . (
  • Postganglionic fibers - Infobox Nerve Name = PAGENAME Latin = neurofibrae postganglionicae GraySubject = GrayPage = Caption = Sympathetic connections of the ciliary and superior cervical ganglia. (
  • As for the heart, parasympathetic nerve fibres synapse deep within the heart muscle, while sympathetic nerve fibres synapse on the surface of the heart. (
  • Sympathetic sprouting in the dorsal root ganglia of the injured peripheral nerve in a rat neuropathic pain model. (
  • Electroacupuncture (EA) at P5-P6 acupoints overlying the median nerve reduces premotor sympathetic cardiovascular neuronal activity in the rostral ventral lateral medulla (rVLM) and visceral reflex pressor responses. (
  • C fibres also include efferent postganglionic sympathetic autonomic fibres. (
  • The activity of the ANS can be determined by measuring cardiac noradrenaline spill overflow to plasma using isotope dilution or by measuring muscle sympathetic nerve activity by microneurography. (
  • The nerve also acts as a conduit for sympathetic fibers that require access to the ciliary body, lacrimal glands , cornea, and conjunctiva of the eye . (
  • Additional sympathetic branches from the cavernous sinus also join the ophthalmic nerve as well. (
  • Immuno) histological analysis was performed with hematoxylin and eosin, azan, and antibodies against S-100 (Schwann cells), tyrosine hydroxylase (postganglionic sympathetic fibers), and vasoactive intestinal peptide (postganglionic parasympathetic fibers). (
  • also, the unmyelinated fibers at the dorsal roots and at free nerve endings having a diameter of 0.3 to 1.3 μm and a conduction velocity of 0.6 to 2.3 meters per second. (
  • Type Aα fibers include the type Ia and type Ib sensory fibers of the alternative classification system, and are the fibers from muscle spindle endings and the Golgi tendon, respectively. (
  • Through the plexus, nerve trunks enter the corneal stroma radially and ascend to innervate the corneal epithelium as free of charge nerve endings through the subbasal nerve plexus, which primarily consists of C-fibers. (
  • The cornea is innervated by a densely arranged network of fine nerve endings that are located primarily in the epithelial layer and are supplied by the long ciliary nerves, derived from the trigeminal nerve (cranial nerve V). The long ciliary nerves produce a circular limbal plexus in the eye, from which 70 to 80 nerve trunks enter the corneal stroma, to a depth of 150 μm. (
  • Our work has demonstrated that low-current ( 10 ) (2-4 mA), low-frequency (5 Hz) EA stimulation of the P5-P6 acupoints in cats significantly reduces the extent of myocardial ischemia brought about by an imbalance between oxygen supply and demand during reflex increases in arterial blood pressure, caused by the stimulation of chemosensitive sensory nerve endings in the gallbladder ( 10 , 32 ). (
  • There are four types of pressure receptors in the skin, Pacinian corpuscles, Meissner corpuscles, Merkel discs and Ruffini nerve endings. (
  • Their nerve endings are wrapped with layers of connecting tissue giving them an 'onion like' histological appearance. (
  • When this connective tissue that surrounds the nerve ending is deformed, it presses on the nerve endings triggering an electrical impulse. (
  • Ruffini endings however, though dealing with pressure, their main focus would be stretch of the skin, as their surrounding collagen fibres are parallel to the skin and therefore are highly affected by such a sensation. (
  • Such Stmctures as end plates, trophic endings and a terminal nerve net are described, and said to lie in all layers of the sclera. (
  • Mixed nerves have many functional components both somatosensory with links to the sensory endings in tissue. (
  • They pass through the dermis and penetrate the basement membrane to innervate epidermal cells or remain as free endings. (
  • A f's myelinated fibers of the somatic nervous system having a diameter of 1 to 22 μm and a conduction velocity of 5 to 120 meters per second. (
  • The role of these nerves is to innervate the skin (somatic fibers) and help control. (
  • Unlike somatic nerve innervation, the cornea lacks A-beta fibers, and fibers involved in autonomic function are sparsely present [5]. (
  • Thus EA at acupoints overlying deep and superficial somatic nerves leads to point-specific effects on cardiovascular reflex responses. (
  • The activation of skeletal muscle fibers by somatic nerves results in vasodilation and functional hyperaemia [5]. (
  • The PNS consists of peripheral nerves (craniospinal, somatic, autonomic) with their associated ganglia and connective tissue investments. (
  • Peripheral neuropathy happens when the nerves of the peripheral nervous system suffer damage due to disease, trauma to the nerves or through side effects of a certain. (
  • The peripheral nervous system in animals and man consists of aggregations of nerves. (
  • Small fiber neuropathy occurs when the small fibers of the peripheral nervous system are damaged. (
  • Electroneurography (ENG), also often known as nerve conduction study, is part of the neurophysiological examination of the peripheral nervous system and is often supplemented by electromyographic examination (EMG) with a needle electrode. (
  • The peripheral nervous system (PNS) is connected to the CNS, but lies beyond it - it provides a nerve supply to the rest of the body, and relays messages to and from the CNS. (
  • Sensory neurones of the peripheral nervous system send many primary afferent fibres to the skin. (
  • This paper will focus on C-fibers and briefly summarize the literature concerning anatomy of corneal innervation, present the way corneal afferent imaging may be used as an instrument within the scholarly research of feeling and discomfort, and discuss potential energy and great things about corneal microscopy in accordance with traditional pores and skin biopsy. (
  • There is no relationship between corneal sensitivity and the time since diagnosis of diabetes for a thermally cooling stimulus, suggesting that the A∂ and C fibers of the corneal innervation are affected differently by abnormal glucose metabolism in the diabetic cornea. (
  • the cordlike association of nerve tissues that links the brain and nerve ganglia by innervation to the other organs and tissues of the body. (
  • If the innervation is associated with endometrial pain, it is possible that curtailing the nerve growth could eliminate, even prevent the pain, but only if this disease process is identified early enough. (
  • Three serial neurones in the innervation of the colon by the sacral parasympathetic nerve of the dog. (
  • Electrophysiological and histological techniques were used to study the nature of the innervation of the colon by the sacral parasympathetic nerve of the dog. (
  • Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. (
  • The comparison of the left- and right-side nerve fibers show that there was no significant difference, thus implying a symmetrical sensory innervation of the rat's tail. (
  • Innervation of the Eye' J. C. BEATIE AND DONALD L. STILWELL, JR.* Department o f Anatomy, Stanford School of Medicine, Stanford University, Stanford, California With the exception of the retina all nervous tissue in the eye orginates in the ciliary nerves. (
  • Arnold (1863) was among the first to describe the iridial innervation, and provided an accurate drawing of the distribution of larger nerve bundles. (
  • The vascular system of the head, face, meninges and the brain have a variable innervation of autonomic and sensory nerves [ 12 ]. (
  • Because of the arrangement of the spinal nerves and innervation of the skin of the body - it is a very important concept. (
  • The MPG efferent nerves spread out preganglionic information to several pelvic organs controlling urinary, bowel, reproductive and sexual functions, while AG innervation is more regional, and it is confined to reproductive organs located in the rostral region of the urogenital tract. (
  • Each type I axon innervates only a single inner hair cell, but each inner hair cell is innervated by up to 30 such nerve fibers, depending on species and location within the cochlea. (
  • The myelinated nerve fibre is formed by an axon and Schwann cells or oligodendrocytes that sheath the axon by winding around it in tight myelin layers. (
  • Repetitive stimulation of a fibre is known to result in accumulation of extracellular potassium ions, especially between the axon and the myelin. (
  • As a result of this failure, K + accumulates in the confined extracellular space between the axon and the sheath (periaxonal space), and to a lesser extent around the node of Ranvier and outside of the fibre. (
  • It is an ovoid structure about 1mm in length, which is lamellated in cross-section like an onion, and is innervated by a myelinated sensory axon which loses its sheath as it traverses the core. (
  • Its axon travels in the posterior limb of the internal capsule behind the pyramidal fibers and terminates in the sensory area of the cerebral cortex (areas 1, 2, and 3). (
  • An axon (from Greek ἄξων áxōn , axis), or nerve fiber , is a long, slender projection of a nerve cell, or neuron , in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body . (
  • The nerve cell body, dendrites, and proximal part of the axon are within the CNS. (
  • 1.a) - The CNS is the nerve cells from axon to axon terminal entirely enclosed in a bony cavity - skull or vertebral canal. (
  • At low levels of use-dependent accommodation (measured as conduction velocity slowing of the first action potential in a train), intervals between spikes increased during conduction along the nerve. (
  • Scaling factor relating conduction velocity and diameter for myelinated afferent nerve fibres in the cat hind limb. (
  • accelerating f's ( accelerator f's ) adrenergic fibers that transmit the impulses that accelerate the heart beat. (
  • because they are thin (2-5 μm in diameter) and myelinated, they send impulses faster than unmyelinated C fibers, but more slowly than other, more thickly myelinated group A nerve fibers. (
  • Differential block of cutaneous nerve fibers with triangularly shaped electrical impulses. (
  • Presented at the First World Congress of the International Association for the Study of Pain Florence, Italy September 1975 Accornero N Bini G Manfredi M: Differential block of cutaneous nerve fibers with triangularly shaped electrical impulses. (
  • Accornero N, Bini G, Manfredi M: Differential block of cutaneous nerve fibers with triangularly shaped electrical impulses. (
  • The motor conduction evaluation is based on applying electric impulses to the skin (over the course of the nerve), causing a depolarizing square wave in the peri-pheral nerve and recording the response from the relevant innervated muscle. (
  • Rectangular electric impulses of 0.1 to 0.2 ms duration and super maximum intensity (exceeding by 20-30% the intensity causing the maximum sensory response - nerve action potential, SNAP) are used for the stimulation, similarly to the motor fibre examinations. (
  • Each component of the nerve is responsible for a specific region of the face , and transmits specific impulses. (
  • Like the ophthalmic branch, the maxillary division of the trigeminal nerve (CN V2) is a purely sensory entity that carries impulses from the midface. (
  • ii) Optimum physiological fluid environment for neural functions e.g. conduction of nerve impulses, transport of aminoacids, sugars, etc. (
  • Animal studies have documented that two main components such as (1) dichotomy of primary afferent fibers innervating two pelvic organs and (2) common convergence of two afferent fibers onto a spinal dorsal horn are contributing factors for organ-to-organ pain overlap. (
  • The small fibers sense pain and itch, innervate internal organs and tissues, and modulate the inflammatory and immune responses. (
  • Women with endometriosis and pelvic pain almost always have fine, unmyelinated nerve fibers present in the functional layer of endometrium, and these nerve fibers are also greatly increased in the myometrium. (
  • the pelvic nerve (PN) innervates regions such as the bladder and proximal urethra. (
  • Compound action potentials in responses of rectal strands of the pelvic nerve to stimulation of the sacral ventral roots decreased or disappeared after hexamethonium bromide (C6) was applied to the pelvic plexus. (
  • Many C fibres were observed by electron microscopy in the rectal strands after degeneration of the pelvic and hypogastric nerves. (
  • These results show that the sacral parasympathetic nerve innervating the colon comprises three serial neurones located in the sacral spinal cord, the pelvic plexus and the myenteric plexus. (
  • STUDY OBJECTIVE: To clarify the relationship of hypogastric nerves (HNs) with several pelvic anatomic landmarks and to assess any anatomic differences between the 2 sides of the pelvis, both in cadaveric and in vivo dissections. (
  • We found that the pelvic plexus consists of intricate neural circuits composed of two MPG, and three pairs of AG (AGI, AGII, AGIII) anatomically interrelated through ipsilateral and contralateral commissural nerves. (
  • The pelvic autonomic network has been extensively studied, but the anatomy of nerve fibers branching off the inferior hypogastric plexus to innervate the bladder is less known. (
  • The relationship between the pelvic nerves and surgical planes are unclear. (
  • Nerves can be sensory (also called afferent or centripetal) or motor (also called efferent or centrifugal). (
  • Most efferent motor fibres are Aα (large myelinated). (
  • Efferent nerve fibers belonging to the vesical plexus predominantly expressed tyrosine hydroxylase and little vasoactive intestinal peptide. (
  • The cochlear nerve (also auditory or acoustic neuron ) is one of two parts of the vestibulocochlear nerve , a cranial nerve present in amniotes , the other part being the vestibular nerve. (
  • Produced from the lengthy ciliary nerves, which expand through the nasociliary branch of the ophthalmic department of the trigeminal nerve (Cranial Nerve V), these sensory nerve materials enter the world lateral and medial towards the optic nerve, course through within the suprachoroidal space, and branch to create nerve bundles that encircle the corneoscleral limbus and constitute the limbal plexus. (
  • Unlike the other cranial nerves, the trigeminal nerve is quite large. (
  • Furthermore, the ophthalmic branch also carries fibers arising from the dura mater of the anterior cranial fossa, the frontal sinus , and the superior aspect of the nasal cavity . (
  • Once formed, the ophthalmic nerve also receives its meningeal tributary from the dura of the anterior cranial fossa. (
  • The fifth cranial nerve is the common denominator for many headaches and facial pain pathologies currently known. (
  • Subsequent neuroanatomical and neurochemical studies revealed that most sensory fibres from the intracranial and the extracranial tissues originate in the fifth cranial nerve (CN V) ganglion, also called trigeminal ganglion (TG). (
  • For example, the posterior cranial fossa, is mainly innervated by the occipital nerves. (
  • The present work is a comprehensive description of various aspects of the CN V, the largest of the cranial nerves. (
  • cranial nerves ' brain! (
  • Nerves that originate in the ganglia, trunks, and plexuses of the autonomic nervous system constitute a specific group. (
  • Langley noted the absence of sensory (afferent) nerve cell bodies in autonomic ganglia and defined the ANS as a purely motor system. (
  • We focused on this subject in the current study and were able to observe the development of K + -dependent excitation block under prolonged repetitive stimulation of the nerve. (
  • In this paper, we present a model of a nerve fibre that demonstrates K + -accumulation under the myelin during prolonged repetitive stimulation, and excitation block, caused by K + -dependent structural reorganization in the myelin. (
  • The model exhibits oscillatory, chaotic or stationary behaviour with respect to extracellular potassium concentration and myelin resistance and the fibre therefore shows periodic, chaotic or complete excitation block at high frequencies of stimulation. (
  • Dendrites , also dendrons , are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. (
  • EA at LI6-LI7 and K1-B67 acupoints as well as direct stimulation of the superficial radial nerve did not cause any cardiovascular or rVLM neuronal effects. (
  • Our laboratory has developed a feline model of a partial coronary artery occlusion to study the mechanism of EA's cardiovascular influence during stimulation of the P5-P6 acupoints as well as the median nerve directly. (
  • Records were obtained of each patient's stated relief from pain produced by nerve stimulation, along with assessments of narcotic withdrawal, ability to return to work, sleep pattern, and relief from depression. (
  • Techniques of peripheral stimulator implantation, possible mechanisms of action, and conclusions regarding peripheral nerve stimulation in the treatment of chronic pain are discussed. (
  • Potential changes inside central afferent terminals secondary to stimulation of large- and small-diameter peripheral nerve fibers. (
  • The tonic stimulation waveform is configured to excite A-beta fibers of the nervous tissue. (
  • and adjusting the tonic-burst delay between the tonic and burst stimulation waveforms to deliver the burst stimulation waveform during a refractory period of the A-beta fibers excited by the tonic stimulation waveform to avoid excitation of the A-beta fibers excited by the tonic stimulation waveform. (
  • 4. The method of claim 1, wherein the tonic stimulation waveform is biphasic with first and second phase pulses, the first phase pulse configured to capture at least a portion of the A-beta fibers to deliver a first pain relief, the second phase pulse configured to repolarize charge at a stimulation site to limit excitation of A-beta fibers. (
  • Such a response is called compound muscle action potential (CMAP) and can be recorded with surface electrodes or needle monopolar electrodes placed close to the nerve, especially in case of difficult access by surface electrodes (e.g. stimulation of the sciatic nerve under the buttock, where the nerve is deeply located). (
  • The ENG of sensory fibres is technically more difficult due to small amplitudes (they range from few to a few dozens of microvolts, compared to muscle potentials recorded during the stimulation of motor fibres, which range from few to a few dozen millivolts). (
  • Nerve conduction studies (NCS) allow the stimulation and recording of peripheral nerve function. (
  • Electrical stimulation causes an impulse that travels along motor, sensory, or mixed nerves. (
  • SNAPs and CMAPs are compound potentials representing summated electrical activity of individual nerve fibres with simultaneous activation of nerve stimulation. (
  • Similarly, pain can be referred to a different territory than the actual nerve receiving the painful stimulation. (
  • Rapid switching of applied magnetic fields in the kilohertz frequency range in the human body induces electric fields powerful enough to cause Peripheral Nerve Stimulation (PNS). (
  • Peripheral Nerve Stimulation (PNS) is a limiting factor in the use of gradient coils in Magnetic Resonance Imaging (MRI), and potentially limits the translation of Magnetic Particle Imaging (MPI) to humans. (
  • The number and caliber of myelinated and unmyelinated fibers of the sacrococcygeal dorsal roots innervating the tail of rats were studied by means of light and electron microscopy. (
  • Activated immune cells produce inflammatory mediators, such as cytokines, lipid mediators, and histamine, which directly stimulate the terminals of peripheral nerves in local tissues. (
  • In mammals, temperature receptors innervate various tissues including the skin (as cutaneous receptors), cornea and bladder. (
  • Short preganglionic fibre short postganglionic fibre myelinated unmyelinated cholinergic autonomic transmitter released from tissue, enters circulation, acts on cholecystokinin neighbouring cells, relatively rapid action endocrine secretion classic hormone released from. (
  • Conduction velocities of the potentials showed that most of the preganglionic fibres were B fibres, and nearly all the post‐ganglionic fibres were C fibres. (
  • Pruriceptive itch is the most common and occurs when sensory afferent nerve fibres innervating the skin are activated by various exogenous or endogenous pruritogens (mediators of itch). (
  • This is the dense fibrous connective tissue that interpenetrates and surrounds the muscles, bones, nerves and blood vessels of the body. (
  • thus when blood vessels branch to vascularise developing lesions, termed angiogenesis, nerves innervating those blood vessels may also branch (neural sprouting), thereby enabling nerves to invade lesions. (
  • Groups of myelinated fibers fan out in a horizontal plane to form a branching network from which fibers ascend, usually accompanying blood vessels, to form a mesh of interlacing nerves in the superficial dermis. (
  • Both MPG and AG contain nerve fascicles, blood vessels, small intensely fluorescent cells, satellite cells and oval neuronal somata with one to three nucleoli. (
  • Peripheral neuropathy is not just limited to the somatosensory nerves, but the autonomic nervous system too (autonomic neuropathy). (
  • At the site of the incision, the ulnar sub-branch (US) of the palmar cutaneousbranch of the median nerve (PCBMN), which innervates the skin over the hypothenar eminence, was found in 10 of 15 cases. (
  • The responses observed may have been due to a thermo-cooling effect of the gel or due to the direct effect of US on C fibers of median and ulnar nerves. (
  • Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. (
  • A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. (
  • One well-recognized set of acupoints, Jianshi-Neiguan (located along the pericardial meridian, P5-P6), is positioned directly over the median nerve on the wrist and is used frequently to treat symptomatic coronary heart disease ( 12 , 26 , 37 ). (
  • There are certain primarily motor (e.g. anterior interosseous branch of the median nerve, posterior interosseous branch of the radial nerve) and primarily sensory fibres (e.g. sural nerve, peripheral peroneal nerve, superficial radial nerves) that allow neurophysiologic investigation. (
  • Sensory perception thresholds (sPT) for ulnar and median nerves were determined using the Neurometer, from ring fingers to assess A beta (Aβ at 2000 Hz) and C fibre (at 5Hz) function. (
  • The neurotransmitters diffuse across the narrow space between the hair cell and a nerve terminal, where they then bind to receptors and thus trigger action potentials in the nerve. (
  • Different sensory receptors are innervated by different types of nerve fibers. (
  • Type Aβ fibres, and type Aγ, are the type II afferent fibers from stretch receptors. (
  • Each pair innervates the effectors and receptors of a certain part of the body. (
  • This survey will review some of the recent evidence which indicates that activation of primary afferent fibres provokes synaptically-elicited responses in the spinal cord which are due to activation of peptide receptors and therefore, by inference, that peptide release has occurred. (
  • Development of the system entails development of nerve fibers and receptors in the fetus body system. (
  • A noradrenergic terminal has been shown to possess receptors for a wide range of substances, so-called heteroceptors (see Langer 1981, 1997) and although this may be useful for developing drugs to manipulate noradrenergic transmission it seems unlikely that in vivo all of the receptors could be innervated by appropriate specific synapses or reachable by their NT. (
  • Fifty-one single C-afferent units (31 mechano-responsive, 20 mechano-insensitive) were recorded from cutaneous fascicles of the peroneal nerve in awake human subjects. (
  • Morphometric analysis of nerve cross sections from the site of the incision and from the main nerve trunk proximal to cutaneous arborisation was performed using light and transmission electron microscopy and a computer-based image analysis system. (
  • In general, headache pain is referred to a cutaneous territory area on the scalp, sharing supply with a nerve innervating the intracranial area, which might be the actual source of pain. (
  • 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. (
  • The cornea may be the most densely innervated framework in mammals and it has been reviewed at length elsewhere [1]. (
  • In chronic pain conditions, nerve morphology alterations in the skin and cornea have been correlated with disease condition in both the peripheral and central nervous system [6,7,8]. (
  • can disease conditions bring about alterations in small-fiber density in both AMG-176 skin and cornea? (
  • The microneurography technique was used to analyze use-dependent frequency modulation of action potential (AP) trains in human nociceptive peripheral nerves. (
  • Based on the con-temporary feedback neural circuits of pain transmission in spinal cord, it is summarized that the Aδ- and C-fibers relay the sensory noxious signals to the laminae I, II and V of dorsal spinal horn, and in turn activate the peria-queductal grey (PAG) in midbrain, which feedbacks via raphe to inhibit the nociceptive transmission of spinal cord. (
  • collagen f's ( collagenous f's ) the soft, flexible, white fibers that are the most characteristic constituent of all types of connective tissue, consisting of the protein collagen, and composed of bundles of fibrils that are in turn made up of smaller units ( microfibrils ) that show a characteristic crossbanding with a major periodicity of 65 nm. (
  • Like ligaments , aponeuroses , and tendons , fascia is made up of fibrous connective tissue containing closely packed bundles of collagen fibers oriented in a wavy pattern parallel to the direction of pull. (
  • the thin interstitial layers of connective tissue that separate the individual fibers deep within the bundle constitute the endoneurium. (
  • A bundle of nerve fibers or processes held together by connective tissue. (
  • The main nerve trunks entering the subdermal fatty tissue each divide into smaller bundles. (
  • Complex regional pain syndrome (CRPS) results from damage to C-fibers and A-delta fibers that innervate soft tissue and bone in the great majority of instances. (
  • This may be seen, at some level, as an extension of the normal healing process, whereby tissue or nerve damage elicits hyperactivity to promote guarding of the injured area. (
  • Arachnoid mater made up of reticular connective tissue with collagen and elastin fiber, while innermost vascular piamater (nutritive) made up of loose aerolar connective tissue. (
  • Thus, we are examining changes in pain nerve (nociceptor) gene expression in skin and nerve tissue. (
  • The epidermis can be considered a true sensory tissue where sensor proteins and neurone-like properties enable epidermal cells to participate in the skin surface perception through interactions with nerve fibres. (
  • In man there are 31 pairs of spinal nerves: eight cervical, 12 thoracic, five lumbar, five sacral, and one coccygeal. (
  • The spinal nerves branch from the spinal cord into two roots-the posterior, or sensory, and the anterior, or motor. (
  • How are spinal nerves or mixed spinal nerves formed? (
  • spinal nerves ' spinal cord! (
  • Unmyelinated neurones postganglionic fibres and some elastic fibres, which increase and helper t - cells ige found on the cuff. (
  • The particular subpopulations of peripheral neurones implicated in histamine-mediated itch are unmyelinated mechanically-insensitive C fibres (C-MIAs) and a few myelinated Aδ fibres, which reside at the epidermal-dermal junction of the skin [12] [13] . (
  • Small fiber peripheral neuropathy is a type of peripheral neuropathy that occurs from damage to the small unmyelinated peripheral nerve fibers. (
  • Changes in corneal nerve function and structure through direct damage, metabolic changes, or Gdf6 systemic inflammatory processes may contribute to changes in corneal morphology. (
  • While skin biopsies have been sensitive for many small fiber or mixed neuropathies, the specificity and sensitivity of corneal nerve evaluation using corneal confocal microscopy (CCM) is much less well defined. (
  • Some 7000+ PubMed citations are listed for the search term skin biopsy and pain and some 22 for corneal nerve measures and pain. (
  • This instrument uses a controlled pulse of air to produce a small, localized reduction in the surface temperature of the eye, which is detected by the nerves in the corneal epithelium. (
  • The fibers are of two main types, and they are arranged within the epithelium according to their type: myelinated A∂ fibers that run parallel to the corneal surface within the basal cell layer and unmyelinated C fibers that turn upward from the epithelial plexus toward the surface. (
  • Earlier Cohnheim (1867), Hoyer (1877), Dogie1 (1890,1891), Attias ('12), Ernyei ('34), and Boeke ('35) used various techniques to compare the corneal nerves in several species. (
  • cholinergic f's nerve fibers such as the parasympathetic fibers that liberate acetylcholine at a synapse when a nerve impulse passes. (
  • 6, 7 Variant forms may also occur, 5 in which sensory fibres are involved 8, 9 or cholinergic autonomic fibres alone are affected. (
  • there are more than 1 million in the human optic nerve. (
  • 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. (
  • Dr. Plant's current research interests are spinal cord injury, human mesenchymal and induced pluripotent stem cell transplantation, olfactory ensheathing glia, Schwann cell biology and transplantation, peripheral nerve and optic nerve injury. (
  • Retrograde degeneration to the retina and anterograde degeneration to the optic radiations from the optic nerve was observed in both MS and NMO subjects with optic neuritis history. (
  • Finally, damage was observed in optic pathway in MS patients without optic neuritis history suggesting that there is damage in the absence of lesions in the optic nerve. (
  • in contrast, the optic nerve is composed of a mere one million fibers. (
  • Group A nerve fibers are one of the three classes of nerve fiber as generally classified by Erlanger and Gasser. (
  • There are four subdivisions of group A nerve fibers: alpha (α), beta (β), gamma (γ), and delta (δ). (
  • Nerve fibers are classed into three types - group A nerve fibers , group B nerve fibers , and group C nerve fibers . (
  • They are known to be innervated by A-beta fibres and to have large receptive fields similar to the Pacinian Corpuscles. (
  • Electrophysiological recordings from the trigeminal ganglion and peripheral nerves were made to isolate single-unit receptive fields and to test possible osmoreceptive and electroreceptive functions. (
  • Even however a few of these ""naked"" groupings most likely result from losing myelin, their own widespread occurrence inside regular examples since affecting the pan-specific NaCh examine and also the conclusions presented below offer further evidence for living throughout unmyelinated fibres. (
  • In MS, the immune system damages and destroys myelin, the material that surrounds and protects nerve fibers in the brain and spinal cord. (
  • Individual nerves are generally classified based on their diameters, conductivity, and myelin properties. (
  • Autonomic neuropathies are disorders affecting the peripheral nerves that automatically ( without conscious effort) regulate body processes (autonomic nerves). (
  • Aside from diabetes (see diabetic neuropathy) and other metabolic conditions, the common causes of painful peripheral neuropathies are herpes zoster infection, HIV-related neuropathies, nutritional deficiencies, toxins, remote manifestations of malignancies, immune mediated disorders and physical trauma to a nerve. (
  • We also document for the first time that entrapment neuropathies lead to a clear reduction in intraepidermal nerve fibre density, which was independent of electrodiagnostic test severity. (
  • In other words, NCS is normal in pure small-fibre neuropathies. (
  • Immunotherapy Prospects for Painful Small-fiber Sensory Neuropathies and Ganglionopathies. (
  • The best-known peripheral neuropathies are those affecting the large, myelinated motor and sensory fibers. (
  • alpha f's motor and proprioceptive fibers of the A type having conduction velocities of 70 to 120 meters per second and ranging from 13 to 22 micrometers in diameter. (
  • Each of our final results and also the connection between other individuals declare that several unmyelinated neural materials truly originated from myelinated fibers and so much of the anguish associated with tooth pain could actually entail the particular service regarding greater diameter nerves. (
  • The results showed that from the second sacral (S2) to the fourth sacral (S4) segment, the fiber diameter spectrum of myelinated fibers within each dorsal root was bimodal with two peaks at 5 microns and 10 microns, respectively. (
  • The fiber diameter of unmyelinated fibers of all these roots was unimodal with a single peak at 0.5 microns. (
  • The speed of conduction is dependent on the nerve fibre diameter, with the largest fibres conducting the fastest. (
  • Trigeminal nerve (CN V): want to learn more about it? (
  • The principal regulator of the sensory modalities of the head is the trigeminal nerve . (
  • While the trigeminal nerve (CN V) is largely a sensory nerve, it also mingles in the realm of motor supply. (
  • The goal of this article will be to discuss the anatomy, pathway, and distribution of the trigeminal nerve. (
  • Further discussion surrounding clinical examination to assess the integrity of the trigeminal nerve will also be included. (
  • As the name suggests, the trigeminal nerve is a tripartite entity made up of distinct terminal divisions. (
  • The acronym MOM can be used to recall the three branches of the trigeminal nerve. (
  • The ophthalmic branch is the first division of the trigeminal nerve. (
  • The branches of the ophthalmic division of the trigeminal nerve are summarized below. (
  • Additionally, the zygomatic , pterygopalatine , and the posterior superior alveolar nerves unite at the opening of the foramen rotundum to form the maxillary branch of the trigeminal nerve. (
  • We hope that this overview can elucidate the complex field of headache pathologies, and their link to the trigeminal nerve, to a broader field of young scientists. (
  • In this review we explore the trigeminal nerve, its related pain conditions and current treatments to emphasize its importance to headache pathophysiology. (
  • There are subsequently reduced numbers of motor fibres, each having increased motor unit territories and increased muscle fibre per motor units numbers. (
  • These collagen fibers are produced by fibroblasts located within the fascia. (
  • Type Aβ fibres from the skin are mostly dedicated to touch. (
  • Because these small fibers innervate skin and help control autonomic function, their neuropathy presents with neuropathic pain, reduced thermal and pain sensitivity, and autonomic dysfunction (e.g. abnormal sweating or facial flushing). (
  • The skin is innervated with around one million afferent nerve fibers. (
  • Small fibers in the skin relay sensory. (
  • This study demonstrated minor reductions in skin blood flow, skin temperatures, and C fiber perception thresholds immediately after 3 MHz, and 1 MHz US. (
  • Associated with each level is a spinal nerve that goes out and with regards to that sensory nerve innervates a band of skin at that level - sensory only. (
  • The dermatome is a slice of skin innervated by a nerve. (
  • Dermatomes are the area of skin innervated by a particular dorsal root. (
  • To address these issues, we transected the sciatic nerve in mice and compared the changes of epidermal thickness in different areas of the hind foot skin. (
  • The skin can detect patterns at a very fine and smaller scale, which suggests that nerve terminals are helped by epidermal sensors. (
  • Evolutionarily, the itch-scratch reflex developed in mammals as a defence mechanism to aid removal of harmful environmental threats such as irritant plant fibres or parasites from the surface of the skin [2] . (
  • Autonomic nerves that control functions such as blood pressure, heart rate, digestion and bladder. (
  • Applebaum AE, Vance WH, Coggeshall RE (1980) Segmental localization of sensory cell that innervate the bladder. (
  • Localization of afferent nerves next to the urothelium suggests that urothelial cells could be targets for neurotransmitters released from bladder nerves or that chemicals released by urothelial cells could alter afferent nerve excitability. (
  • Although oncological outcome is good with regard to recurrence and survival rates, it is well known that RHL might result in postoperative bladder impairments due to autonomic nerve disruption. (
  • RESULTS: The vesical plexus formed a group of nerve fibers branching off the ventral part of the inferior hypogastric plexus to innervate the bladder. (
  • This travels in parallel with the vestibular nerves through the internal auditory canal , through which it connects to the brainstem. (
  • Responses of FCs are further shaped by feed-forward inhibition, mainly through inhibitory tuberculo-ventral cells activated by AN fibers and cartwheel cells activated by parallel fibers ( 17 , 29 ⇓ - 31 ). (
  • With an acute nerve lesion, before the onset of nerve regeneration, there is a loss of motor nerve fibres in parallel with the loss of activatable muscle fibres. (
  • The basic concept of the Marr-Albus theory is that the climbing fiber serves as a "teaching signal", which induces a long-lasting change in the strength of synchronously activated parallel fiber inputs. (
  • Observations of long-term depression in parallel fiber inputs have provided support for theories of this type, but their validity remains controversial. (
  • citation needed] The inner hair cells transform the sound vibrations in the fluids of the cochlea into electrical signals that are then relayed via the auditory nerve to the auditory brainstem and to the auditory cortex. (
  • In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma. (
  • A reduction in the number of myelinated auditory nerve fibers leads to a reduced maximal firing rate of DCN principal cells, which cannot be restored by increasing auditory nerve fiber recruitment. (
  • It is well established that exposure to loud sound causes damage to the cochlea and results in an elevation of hearing thresholds ( 1 ) often accompanied by a reduction of auditory nerve (AN) firing rate ( 2 ⇓ - 4 ). (
  • From this basal cell layer plexus, nerve fibers ramify anteriorly toward the epithelial surface. (
  • for example, the sacral portion of the lumbosacral plexus gives rise to the sciatic nerves. (
  • The phrenic nerve in its early course close to its origin was giving a communicating branch to C5 root of brachial plexus and at the level of the root of neck just before entering the thorax, the phrenic nerve was placed anterior to the subclavian vein. (
  • These corpuscles are innervated via myelinated fibres from the subepidermal nerve plexus that lose their myelination as they enter the corpuscle. (
  • RESULTS: Myelinated and sensory fibres were detected at the inferior hypogastric plexus (IHP) level. (