Nerve Fibers: 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.Nerve Fibers, Unmyelinated: A class of nerve fibers as defined by their nerve sheath arrangement. The AXONS of the unmyelinated nerve fibers are small in diameter and usually several are surrounded by a single MYELIN SHEATH. They conduct low-velocity impulses, and represent the majority of peripheral sensory and autonomic fibers, but are also found in the BRAIN and SPINAL CORD.Nerve Fibers, Myelinated: 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.Sciatic Nerve: 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.Peripheral Nerves: 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.Axons: Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.Neural Conduction: The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.Optic Nerve: 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.Dietary Fiber: The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.Muscle Fibers, Skeletal: 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.Sural Nerve: A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Spinal Nerve Roots: 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.Myelin Sheath: 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.Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Mineral Fibers: Long, pliable, cohesive natural or manufactured filaments of various lengths. They form the structure of some minerals. The medical significance lies in their potential ability to cause various types of PNEUMOCONIOSIS (e.g., ASBESTOSIS) after occupational or environmental exposure. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p708)Nerve Endings: 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.Microscopy, Electron: 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.Schwann Cells: Neuroglial cells of the peripheral nervous system which form the insulating myelin sheaths of peripheral axons.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Nociceptors: 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.Adrenergic Fibers: Nerve fibers liberating catecholamines at a synapse after an impulse.Muscle Fibers, Fast-Twitch: 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.Muscle Fibers, Slow-Twitch: 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.Ophthalmic Nerve: 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.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Cats: 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)Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Retinal Ganglion Cells: 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.Cotton Fiber: 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.Mechanoreceptors: 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.Ganglia, Spinal: 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.Peripheral Nerve Injuries: Injuries to the PERIPHERAL NERVES.Optic Nerve Diseases: 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.Nerve Block: 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.Capsaicin: An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.Trigeminal Nerve: 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.Optic Disk: 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.Cochlear 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.Peripheral Nervous System Diseases: 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.Ubiquitin Thiolesterase: A thioester hydrolase which acts on esters formed between thiols such as DITHIOTHREITOL or GLUTATHIONE and the C-terminal glycine residue of UBIQUITIN.Tomography, Optical Coherence: 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.Spinal Nerves: 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.Sensory Receptor Cells: 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.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Ranvier's Nodes: 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.Wallerian Degeneration: 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.Rats, Sprague-Dawley: 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.Tibial Nerve: 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.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Calcitonin Gene-Related Peptide: 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.Stress Fibers: 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.Median Nerve: 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.Substance P: 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.Nerve Crush: Treatment of muscles and nerves under pressure as a result of crush injuries.Muscles: Contractile tissue that produces movement in animals.Diabetic Neuropathies: 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)Ulnar Nerve: 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.Facial Nerve: 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.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Nerve Degeneration: 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.Purkinje Fibers: Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Neurofilament Proteins: 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)Nerve Growth Factors: Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.Glaucoma: 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)Histocytochemistry: 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.Muscle Contraction: 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.Sympathetic Nervous System: 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.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Mossy Fibers, Hippocampal: 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).Peripheral Nervous System: 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.Denervation: The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)Peroneal Nerve: 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.Motor Neurons: Neurons which activate MUSCLE CELLS.Muscle, Skeletal: 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.Radial Nerve: 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.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Nerve Growth Factor: 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.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Femoral Nerve: A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.Nerve Tissue: Differentiated tissue of the central nervous system composed of NERVE CELLS, fibers, DENDRITES, and specialized supporting cells.Neurons: 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.Diagnostic Techniques, Ophthalmological: Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.Reflex: 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.Mandibular Nerve: 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.Vagus Nerve: 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).Autonomic Fibers, Preganglionic: 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.Sensation: 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.Neuronal Tract-Tracers: Substances used to identify the location and to characterize the types of NEURAL PATHWAYS.Glossopharyngeal Nerve: 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.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Birefringence: 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)Contactin 1: A contactin subtype that is predominantly expressed in the CEREBELLUM; HIPPOCAMPUS; NEOCORTEX; and HYPOTHALAMUS.Mice, Neurologic Mutants: Mice which carry mutant genes for neurologic defects or abnormalities.Nerve Compression Syndromes: 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.Phrenic Nerve: 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.Tetrodotoxin: 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.Vestibulocochlear Nerve: 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.Retina: 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.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.Cantharidin: 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.Nerve Tissue ProteinsCranial Nerves: Twelve pairs of nerves that carry general afferent, visceral afferent, special afferent, somatic efferent, and autonomic efferent fibers.Trochlear Nerve: The 4th cranial nerve. The trochlear nerve carries the motor innervation of the superior oblique muscles of the eye.Hindlimb: 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)Chronaxy: 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.Thermosensing: The sensation of cold, heat, coolness, and warmth as detected by THERMORECEPTORS.Membrane Potentials: 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).Axonal Transport: 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)Rabbits: 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.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Ophthalmoscopy: Examination of the interior of the eye with an ophthalmoscope.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Axotomy: 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.Tongue: 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.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Visual Field Tests: Method of measuring and mapping the scope of vision, from central to peripheral of each eye.Animals, Newborn: Refers to animals in the period of time just after birth.Olfactory Nerve: 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.Electrophysiology: 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.TRPV Cation Channels: 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.Hyperalgesia: 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.Lidocaine: 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.Lasers: 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.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Sodium Channels: 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.NAV1.6 Voltage-Gated Sodium Channel: 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.Mustard Plant: 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.Synaptic Transmission: 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.Synapses: 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.Neuralgia: Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.Rats, Inbred Strains: 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.Scanning Laser Polarimetry: 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.Disease Models, Animal: 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.Optic Nerve Injuries: 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.Intraocular Pressure: The pressure of the fluids in the eye.Pain Threshold: Amount of stimulation required before the sensation of pain is experienced.Macaca fascicularis: 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.Mononeuropathies: 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.Urinary Bladder: 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.Accessory Nerve: 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.Splanchnic Nerves: 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.Myofibrils: The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .Chorda Tympani Nerve: 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.Microscopy, Confocal: 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.Presynaptic Terminals: 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.Glaucoma, Open-Angle: Glaucoma in which the angle of the anterior chamber is open and the trabecular meshwork does not encroach on the base of the iris.Vasoactive Intestinal Peptide: 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).Elastic Tissue: Connective tissue comprised chiefly of elastic fibers. Elastic fibers have two components: ELASTIN and MICROFIBRILS.Cholinergic Fibers: Nerve fibers liberating acetylcholine at the synapse after an impulse.Lingual Nerve: 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.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Microscopy, Immunoelectron: Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.Receptor, trkA: 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.Thiolester HydrolasesOculomotor Nerve: 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.Reference Values: 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.Fluorescent Antibody Technique: 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.Neuromuscular Junction: The synapse between a neuron and a muscle.Evoked Potentials: 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.Photography: Method of making images on a sensitized surface by exposure to light or other radiant energy.Neuroglia: 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.Cochlear Nucleus: 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.Mice, Inbred C57BLPain Measurement: 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.Myosin Heavy Chains: The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.Rana temporaria: A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.Touch: Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.Retinal Neurons: 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.Cerebellum: The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.Trigeminal Ganglion: 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.Neuropeptide Y: 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.Rana pipiens: A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.Asbestos: Asbestos. Fibrous incombustible mineral composed of magnesium and calcium silicates with or without other elements. It is relatively inert chemically and used in thermal insulation and fireproofing. Inhalation of dust causes asbestosis and later lung and gastrointestinal neoplasms.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Glass: Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Thoracic Nerves: 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.Corpus Callosum: Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Cornea: 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)Tomography: Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane.Anesthetics, Local: 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.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Abducens Nerve: 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.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Reaction Time: The time from the onset of a stimulus until a response is observed.Autonomic Fibers, Postganglionic: Nerve fibers which project from cell bodies of AUTONOMIC GANGLIA to SYNAPSES on target organs.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Pressoreceptors: Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.Acetylcholinesterase: 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 188.8.131.52.Neuroma: A tumor made up of nerve cells and nerve fibers. (Dorland, 27th ed)Parasympathetic Nervous System: 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.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Guinea Pigs: 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.Recurrent Laryngeal Nerve: 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.Sciatic Neuropathy: 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)
Congenital insensitivity to pain with anhidrosis
In addition, patients typically lack unmyelinated and small myelinated nerve fibers in the dorsal root ganglion. Both are ... though they lack innervations by small diameter neurons. CIPA is caused by a genetic mutation which prevents the formation of ... and results of nerve conduction studies". Am. J. Med. Genet. 92 (5): 353-60. doi:10.1002/1096-8628(20000619)92:5. 3.0.CO;2-C. ... or any real nerve-related sensations (including feeling the need to urinate); however, patients can still feel pressure. CIPA ...
C tactile afferent
CT afferents belong to group C nerve fibers, and are unmyelinated, have a small diameter and slow conduction velocity. CT ... C tactile (CT) afferents are a class of nerve fibers that innervate the human skin. ... CT afferents project to the insular cortex in the brain, and the firing frequency of CT fibers correlate with perceived ... Vallbo, Åke; Olausson, Håkan; Wessberg, Johan; Norrsell, Ulf (1993). "A system of unmyelinated afferents for innocuous ...
The corpuscle is 30-140 μm in length and 40-60 μm in diameter. A single nerve fiber meanders between the lamellae and ... Tactile corpuscles are encapsulated unmyelinated nerve endings, which consist of flattened supportive cells arranged as ... They are a type of nerve ending in the skin that is responsible for sensitivity to light touch. In particular, they have their ... Any physical deformation in the corpuscle will cause an action potential in the nerve. Since they are rapidly adapting or ...
Gate control theory
... unmyelinated, slow "C" fiber that carries the longer-term throbbing and chronic pain. Large-diameter Aβ fibers are ... and large diameter (touch, pressure, vibration) nerve fibers carry information from the site of injury to two destinations in ... unmyelinated) and thick (myelinated) fibers in 1959. The fast (myelinated) fibers block the slow (unmyelinated) fibers, "fast ... Thin fiber activity impedes the inhibitory cells (tending to allow the transmission cell to fire) and large diameter fiber ...
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 ... The cochlear nerve (also auditory or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve ... There, its fibers synapse with the cell bodies of the cochlear nucleus. In mammals, cochlear nerve fibers are classified as ...
Because fibers are mixed in most nerves, it is usually essential to record from an individual nerve fiber at a time to explore ... This is true for fibers of different functions as well as fibers of different size. Basically fiber diameter is closely related ... unmyelinated C-afferents and small myelinated Aδ fibers. Most studies are focused on C nociceptiors. The nociceptive C-fibers ... With regard to fiber diameter there are two main categories: A-fibers are large and conduct impulses at high or moderate speed ...
Dorsal root of spinal nerve
The lateral division of the dorsal root contains lightly myelinated and unmyelinated fibres of small diameter. These carry pain ... "Spinal Root Nerve Fibers" Dorsal Root - Cell Centered Database. ... Nerve fibres with the ventral root then combine to form a ... The dorsal root of spinal nerve (or posterior root of spinal nerve) is one of two "roots" which emerge from the spinal cord. It ... The dura is opened and arranged to show the nerve roots. Scheme showing structure of a typical spinal nerve. Ventral root ...
A delta fiber
... they send impulses faster than unmyelinated C fibers, but more slowly than other, more thickly myelinated group A nerve fibers ... The fibers terminate at Rexed laminae I and V. Aδ fibers are thin (2 to 5 μm in diameter), myelinated axons with moderate ... An A delta fiber, alpha delta fiber, or Aδ fiber is an afferent nerve fiber of a nociceptor. Aδ fibers carry cold, pressure and ... Aδ fibers serve to receive and transmit information primarily relating to acute pain - described as sharp, immediate, and ...
Group C nerve fiber
The C group fibers are unmyelinated and have a small diameter and low conduction velocity. They include postganglionic fibers ... and nerve fibers at the dorsal roots (IV fiber). These fibers carry sensory information. Damage or injury to nerve fibers ... C fibers are one class of nerve fiber found in the nerves of the somatic sensory system. They are afferent fibers, conveying ... A nerve fibers B nerve fibers Free nerve ending Nociceptor Pain and nociception Sensory neuron Thermoreceptor Purves, Dale; et. ...
... group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. These groups ... and identified several types of nerve fiber, establishing a relationship between the diameter of an axon and its conductance ... Nerve fibers are classed into three types - group A nerve fibers, ... An axon (from Greek ἄξων áxōn, axis) or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that typically ...
All nerve fibers are sensitive to LAs, but due to a combination of diameter and myelination, fibers have different ... Although type B fibers are thicker than type C fibers, they are myelinated, thus are blocked before the unmyelinated, thin C ... Peripheral nerve block is injection of LA in the vicinity of a peripheral nerve to anesthetize that nerve's area of innervation ... Small and large peripheral nerves can be anesthetized individually (peripheral nerve block) or in anatomic nerve bundles ( ...
The insulation must be proportional to the diameter of the fiber inside. The optimal ratio of axon diameter divided by the ... impulse speed of myelinated axons increases linearly with the axon diameter, whereas the impulse speed of unmyelinated cells ... oligodendrocytes are closely related to nerve cells, and, like all other glial cells, oligodendrocytes provide a supporting ... total fiber diameter (which includes the myelin) is 0.6. In contrast, satellite oligodendrocytes are functionally distinct from ...
However, the myelin layer does not ensure a perfect regeneration of the nerve fiber. Some regenerated nerve fibers do not find ... In unmyelinated fibers, electrical impulses (action potentials) travel as continuous waves, but, in myelinated fibers, they " ... The latter is markedly faster than the former, at least for axons over a certain diameter. Myelin decreases capacitance and ... and PNS nerves (e.g. the sciatic nerve and the auditory nerve, which also appear white) each comprise thousands to millions of ...
... and specifically the progressive myelination of nerve axon fibers in the central nervous system. This is a non-simultaneous ... they found that myelinogenesis in the rat optic nerve initially commences with axons the largest diameters before proceeding to ... long allowed for experimental observation of myelinogenesis in a model organism nerve that consists entirely of unmyelinated ... In the optic nerve, the oligodendrocyte cells divided for the final time at five days, with the onset of myelin formation ...
Node of Ranvier
Myelination of nerve fibers. The complex changes that the Schwann cell undergoes during the process of myelination of ... The size and the spacing of the internodes vary with the fiber diameter in a curvilinear relationship that is optimized for ... of voltage-gated sodium and potassium channels is in striking contrast to their diffuse distribution in unmyelinated fibers. ... Soon afterwards, he discovered gaps in sheaths of nerve fibers, which were later called the Nodes of Ranvier. This discovery ...
As the nerve cell matures, these type III IFs are replaced by more complex type IV neurofilaments expanding the diameter of ... In such mice, there was a "34% reduction in the number of L5 unmyelinated sensory fibers that correlated with a decreased ... Nerve growth factor (NGF) plays the major role in the regulation of peripherin. It is both a transcriptional inducer and post- ... In nerve cells, for example, the expressions of different types of IFs relates to the change in shape during development. Early ...
... s are a variety of glial cell that keep peripheral nerve fibres (both myelinated and unmyelinated) alive. In ... influencing transcriptional cascades and shaping the morphology of the myelinated nerve fibers. Schwann cells are involved in ... without an increase in axonal diameter. In this sense, Schwann cells are the peripheral nervous system's analogues of the ... Nerves in the PNS consist of many axons myelinated by Schwann cells. If damage occurs to a nerve, the Schwann cells will aid in ...
Michael A Henry, et al, Unmyelinated nerve fibers in the human dental pulp express markers for myelinated fibers and show ... Intrapulp pressure have an effect on the sensory nerves of varying diameters: blocking larger diameter Aδ-fibres and activating ... Key factors in testing are the enamel and dentine thickness and the number of nerve fibers underlying the pulp. Pulp nerve ... The dull aches are associated with C-fibers and slow Aδ-fibers. As inflammation intensifies, the A-fibers are increasingly ...
There are also unmyelinated axons). Myelin is white, making parts of the brain filled exclusively with nerve fibers appear as ... would become a cable a few centimeters in diameter, extending more than a kilometer. These axons transmit signals in the form ... Most of the space in the brain is taken up by axons, which are often bundled together in what are called nerve fiber tracts. A ... Some types of worms, such as leeches, also have an enlarged ganglion at the back end of the nerve cord, known as a "tail brain ...
Hursh JB (1939). "Conduction velocity and diameter of nerve fibers". American Journal of Physiology. 127: 131-39.. ... scales can be used to understand the dependence of the conduction velocity on the diameter of the neuron in unmyelinated fibers ... Tasaki I (1939). "Electro-saltatory transmission of nerve impulse and effect of narcosis upon nerve fiber". Am. J. Physiol. 127 ... Note that these Purkinje fibers are muscle fibers and not related to the Purkinje cells, which are neurons found in the ...
Hursh JB (1939). "Conduction velocity and diameter of nerve fibers". American Journal of Physiology. 127: 131-39. Lillie RS ( ... scales can be used to understand the dependence of the conduction velocity on the diameter of the neuron in unmyelinated fibers ... Tasaki I (1939). "Electro-saltatory transmission of nerve impulse and effect of narcosis upon nerve fiber". Am. J. Physiol. 127 ... Huxley A (1949). "Direct determination of membrane resting potential and action potential in single myelinated nerve fibers". ...
There are also unmyelinated axons). Myelin is white, making parts of the brain filled exclusively with nerve fibers appear as ... would become a cable a few centimeters in diameter, extending more than a kilometer. These axons transmit signals in the ... Most of the space in the brain is taken up by axons, which are often bundled together in what are called nerve fiber tracts. A ... He postulated that nerves activate muscles mechanically by carrying a mysterious substance he called pneumata psychikon, ...
... and large diameter (touch, pressure, vibration) nerve fibers carry information from the site of injury to two destinations in ... than the unmyelinated C fiber (0.5-2 m/s). Pain evoked by the A-delta fibers is described as sharp and is felt first. This is ... These A-delta and C fibers connect with "second order" nerve fibers in the central gelatinous substance of the spinal cord ( ... spinal cord fibers dedicated to carrying A-delta fiber pain signals, and others that carry both A-delta and C fiber pain ...
... in unmyelinated fibres has been found in clusters associated with lipid rafts along DRG fibers both in vitro and in vivo ... Nav1.8 is expressed specifically in the dorsal root ganglion (DRG), in unmyelinated, small-diameter sensory neurons called C- ... Therefore, nociceptors are easily sensitised by agents such as bradykinin and nerve growth factor, which are released at the ... In myelinated fibres, VGSCs are located at the nodes of Ranvier; however, in unmyelinated fibres, the exact location of VGSCs ...
The essential features are that: the terminal portions of autonomic nerve fibers are varicose and mobile; transmitters are ... The unmyelinated, preterminal axons with very long varicose branches are present in small axon bundles and varicose terminal ... These varicose axons resemble strings of beads with varicosities 0.5-2.0 μ in diameter and 1 to 3 μ in length and separated by ... Nerve terminals may take different forms in different tissues. Nerve terminals appear like a button in the CNS, end plates in ...
... is a process that results when a nerve fiber is cut or crushed and the part of the axon distal to the ... Thomas, PK; King, RH (1 October 1974). "The degeneration of unmyelinated axons following nerve section: an ultrastructural ... Another factor that affects degradation rate is the diameter of the axon: larger axons require a longer time for the ... Within 4 days of the injury, the distal end of the portion of the nerve fiber proximal to the lesion sends out sprouts towards ...
GALAMBOS, R. (Sep 1956). "Suppression of auditory nerve activity by stimulation of efferent fibers to cochlea" (PDF). J ... 0.77 µm compared to 0.37 µm diameter for shell neurons). In contrast, the MOCS contains myelinated nerve fibres which innervate ... The LOCS (originating from both the intrinsic and shell neurons) contains unmyelinated fibres that synapse with the dendrites ... Its nerve fibres, the olivocochlear bundle (OCB), form part of the vestibulocochlear nerve (VIIIth cranial nerve, also known as ...
Group C nerve fiber - Wikipedia
The C group fibers are unmyelinated and have a small diameter and low conduction velocity. They include postganglionic fibers ... and nerve fibers at the dorsal roots (IV fiber). These fibers carry sensory information. Damage or injury to nerve fibers ... C fibers are one class of nerve fiber found in the nerves of the somatic sensory system. They are afferent fibers, conveying ... A nerve fibers B nerve fibers Free nerve ending Nociceptor Pain and nociception Sensory neuron Thermoreceptor Purves, Dale; et. ...
NEUROLOGY Flashcards by Joe Cioccio | Brainscape
000699 - B6.Cg-Dock7|m| Lepr|db|/+ +/J
small numbers of very large unmyelinated fibers (up to 1.6 micrometers). (MGI Ref ID J:6323)*smaller diameter nerve fibers in ... shift of unmyelinated fibers to smaller diameters. (MGI Ref ID J:6323)*significantly shifted to smaller diameter fibers by 25 ... unmyelinated fiber density increase in the sural, peroneal, and vagus nerves. (MGI Ref ID J:6323)*unmyelinated fibers reduced ... myelinated fiber density increases in most nerves (not the peroneal and phrenic nerves) ...
Dorsal root of spinal nerve - Wikipedia
The lateral division of the dorsal root contains lightly myelinated and unmyelinated fibres of small diameter. These carry pain ... "Spinal Root Nerve Fibers" Dorsal Root - Cell Centered Database. ... Nerve fibres with the ventral root then combine to form a ... The dorsal root of spinal nerve (or posterior root of spinal nerve) is one of two "roots" which emerge from the spinal cord. It ... The dura is opened and arranged to show the nerve roots. Scheme showing structure of a typical spinal nerve. Ventral root ...
Free Anatomy Flashcards about A&P I Chapter 11
Group C nerve fibers. Unmyelinated - smalles diameter - no saltatory conduction.. Synapses between axon ending of 1 neuron & ... nerve fibers in PNS. Vital to regen. of damaged peripheral nerve fibers. ... Group A nerve fibers. Thick myelin sheaths & diameter - Somatic sensory & motor - sense skin, skeletal muscles, & joints. ... Gray matter contains __ fibers.. Unmyelinated. Neuorons are grouped structurally according to __.. Numbers of processes ...
Stanley foundation neuropathology consortium PowerPoint (PPT) Presentations, Stanley foundation neuropathology consortium PPTs ...
NOCICEPTORS:1-5MM DIAMETER NERVE FIBERS. A-DELTA: Responsible for temperature and fast or first pain. Is myelinated Conduction ... C-FIBERS: Responsible for slow or second pain, and temperature. Is unmyelinated ... What neuropathologists do!. Perform autopsies to examine : CNS [brain, spinal cord]; PNS [peripheral nerves, end-organ nerves ...
JCI - Neuro-immune crosstalk and allergic inflammation
Most nociceptors are small-diameter, unmyelinated, slowly conducting nerves referred to as C-fibers. Nociceptors express not ... Mast cell-derived tumor necrosis factor can promote nerve fiber elongation in the skin during contact hypersensitivity in mice ... Sensory nerves and neuroendocrine cells regulate asthma pathophysiology. Recent studies have shown that sensory nerves also ... The autonomic nervous system is further divided into the sympathetic nerves and the parasympathetic nerves. The PNS has various ...
Osteogenetic f | definition of osteogenetic f by Medical dictionary
... 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 ... unmyelinated fibers nerve fibers that lack the myelin sheath.. vasomotor fibers unmyelinated nerve fibers going chiefly to ... unmyelinated fs nerve fibers that lack a myelin sheath; see myelin.. visceral fs (visceral nerve fs) nerve fibers, afferent ... gray fibers unmyelinated nerve fibers found largely in the sympathetic nerves.. insoluble fiber that not soluble in water, ...
Metabotropic Glutamate Receptor 5 Upregulation in A-Fibers after Spinal Nerve Injury: 2-Methyl-6-(Phenylethynyl)-Pyridine (MPEP...
... these are unlikely to be present solely on unmyelinated C-fibers.. The notion that A-fibers may mediate pain after nerve injury ... of A-fibers, as well as the small-diameter C-fiber population. Together, these results suggest that capsaicin or RTX treatment ... Furthermore, A-fibers in the uninjured L4 DRG after L5 spinal nerve ligation that have increased mGluR5 are the same A-fibers ... There are differences between spinal nerve ligation and partial nerve section, the main one being that, after spinal nerve ...
nervous system Flashcards by Kim Crouse | Brainscape
PPT - Medical Physics PowerPoint Presentation - ID:2201654
Unmyelinated nerve fiber: They are nerves in which the axons have no myelin sleeve (sheath). ... diameter) have propagation velocities of 20 to 50. * m/sec, whereas the myelinated fibers in man (~10 ... Myelinated nerve fiber: They are nerves in which the membranes of axons are covered witha fatty insulating layer called myelin ... C] Types of Nerve Fibers. Examination of the axons of various neurons with an electron microscope indicates there aretwo ...
Physical Medicine and Rehabilitation for Charcot-Marie-Tooth Disease: Background, Pathophysiology, Epidemiology
A study by Duchesne et al indicated that in addition to myelinated nerve fibers, small unmyelinated fibers are also involved in ... suggested that neurologic dysfunction and clinical disability in CMT-1A are caused by loss or damage to large-diameter motor ... 10] Pain and temperature sensations usually are not affected, because they are carried by unmyelinated (type C) nerve fibers. ... Nerve conduction study showing decreased nerve conduction velocity in the median nerve in an 18-year-old woman with Charcot- ...
Use of Capsaicin Cream for Abdominal Wall Scar Pain - Letters to the Editor - American Family Physician
Capsaicin-sensitive nerves are nociceptors that give rise to small diameter, unmyelinated C fibers (rarely, Ad fibers). The ... Capsaicin may also be useful in other types of abdominal wall pain in which local irritation of nerve endings may be ... Suleiman and Johnston,1 such as rectus nerve entrapment and postherpetic neuralgia. ...
Large kindred evaluation of mitofusin 2 novel mutation, extremes of neurologic presentations, and preserved nerve mitochondria....
C, Myelinated diameter histograms of myelinated fibers (MF) show reduced fiber density of the patients nerve and decreased ... Mitochondrial qualitative axonal evaluation in myelinated large and small unmyelinated fibers of patient VI-9 (A-B), and 100 ... Despite histologically significant loss of nerve fibers, the mitochondria were not distinguishable from diseased sural nerve ... Selected pathologic abnormalities of the sural nerve of patient V1-9. A, Systematically sampled teased fibers. Of 109 evaluated ...
PRIME PubMed | Peripheral neuropathy in myotonic dystrophy: a nerve biopsy study
... a nerve biopsy study. Download Prime PubMed App to iPhone, iPad, or Android ... with preferential loss of large myelinated fibers. Unmyelinated fiber densities and diameters were normal. Teased fiber studies ... with preferential loss of large myelinated fibers. Unmyelinated fiber densities and diameters were normal. Teased fiber studies ... AdultFemaleHumansMaleMicroscopy, ElectronMiddle AgedMuscular DystrophiesNerve Fibers, MyelinatedNeural ConductionPeripheral ...
Quantitative analysis of the retinal ganglion cell layer and optic nerve of the barn owl Tyto alba
... was studied by quantitative analysis of the retina and optic nerve. Cell counts in the ganglion cell layer of the whole-mounted ... Electron microscopy of a single, complete section of the optic nerve revealed a bimodal fiber diameter spectrum (modes at 0.3 ... unmyelinated). Therefore, roughly half of the cells in the retinal ganglion cell layer do not send axons into the optic nerve. ... unmyelinated) to 6.05 microns (myelinated, sheath included). The total axon count for the optic nerve was estimated from sample ...
Cochlear nerve - Wikipedia
They have relatively small diameters, are unipolar, and are unmyelinated.. Cochlear nuclear complex. In mammals, the ... In humans, there are on average 30,000 nerve fibers within the cochlear nerve. 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 ... 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 ...
Neural control of the kidney: functionally specific renal sympathetic nerve fibers | Regulatory, Integrative and Comparative...
... are unmyelinated fibers with a size range of 0.4-2.5 μm. However, when the distribution of fiber diameters was examined, it was ... that the diameters of the nerve fibers involved in the antidiuretic response are greater than the diameters of the nerve fibers ... Anatomic features of renal nerve fibers.. When characterized as to myelination and size, the renal nerves appear to be rather ... By analogy with somatic nerves where stimulation threshold is inversely related to fiber diameter, this suggests ...
Metabolic regulator LKB1 is crucial for Schwann cell-mediated axon maintenance. - PubMed - NCBI
e) Sciatic nerve fiber g-ratios are shown as a function of axon diameter in 12-month-old control and AMPKβ1/2-SCKO mice. Note ... p, q) Quantification of myelinated (p) and unmyelinated axons (q) in sciatic nerves from LKB1fl/fl control and LKB1-SCKO mice ... Note reduced nerve size and axon numbers in mutant saphenous nerves, but no differences in quadriceps nerves from 12-month-old ... a, b) Sciatic nerve g-ratios as a function of axon diameter (a). Note improvement of g-ratio deficits as LKB1-SCKO mutants age ...
Disturbance of Oligodendrocyte Function Plays a Key Role in the Pathogenesis of Schizophrenia and Major Depressive Disorder
At P10, most nerves in the CC of DBZ-KO mice are observed to be unmyelinated and small in diameter (Figure 4(e)). This result ... the average diameter of the nerve fibers was reported to be smaller in the CC of WIRS-exposed mice than those of controls ( ... There were also fewer immunoreactive nerve fibers passing the CC of DBZ-KO mice and their projections to the cingulate (Cg) or ... Repeated exposure to WIRS upregulates NDRG1 phosphorylation in the fiber tracts via SGK1 activation. (a) In situ hybridization ...
Myelin speeds the conduction of nerve impulses by a factor of 10 compared to unmyelinated fibers of the same diameter. * ... To attain the same inter-hemispheric travel time for nerve impulses using unmyelinated axons would require scaling up brain ... Reducing currents surrounding myelinated fibers, which reduces the "cross-talk" between adjacent fibers, permitting closer ... The primary impact is two-fold: on conduction speed and on the metabolic costs of nerve impulses. Beyond these, however, the ...
The C group fibers are unmyelinated and have a small diameter and low conduction velocity. They include Postganglionic fibers ... Group C nerve fiber. Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral ... Group C nerve fiber. Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral ... C fibers are one class of nerve fiber found in the nerves of the somatic sensory system. They are afferent fibers, conveying ...
Wheeless' Textbook of Orthopaedics
Nerve Entrapment:. - w/ entrapment, nerve fibers are not affected uniformly;. - superficially located fibers tend to bear the ... large diameter, heavily myelinated fibers are more sensitive to compression than poorly myelinated fibers;. - thus fibers ... subserving light touch and motor fibers are more likely to be involved in compression neuropathy than unmyelinated pain fibers; ... in most cases nerve has an intact perineural sheath - may result from chronic nerve compression and irritation which causes ...
Afferent Pharmaceuticals Announces Data Supporting Potential Utility of Proprietary P2X3 Antagonists in Regulating Bladder...
C fiber afferent nerves that have dense innervations in visceral organs, skin and joints. These small diameter fibers transmit ... P2X3 receptors are preclinically well-validated targets, highly specific to unmyelinated, ... Validated in numerous preclinical models, P2X3 is highly specific to types of sensory nerves (C fiber afferents) that transmit ... P2X3-containing fibers have been broadly implicated for treating chronic inflammatory, visceral and neuropathic pain. Results ...
Histology of the Peripheral Nerves and Light Microscopy - NYSORA
... and organization of the peripheral nerves and insight into how the characteristics of the peripheral nerves relate to the ... In unmyelinated fibers, conduction velocity is proportional to the square root of fiber diameter and is much slower compared to ... CLASSIFICATION OF NERVE FIBERS. Nerve fibers are classified according to axonal diameter, conduction velocity, type of receptor ... Peripheral nerves contain fascicles of nerve fibers consisting of axons. In peripheral nerve fibers, axons are ensheathed by ...
Visual Neuroscience: Volume 12 - Issue 2 | Cambridge Core
The optic nerve of S. leucodon contains 1790 fibers ranging in diameter from 0.07-2.30 μm (mean = 0.57 μm), whereas in S. ... The unique presence of unmyelinated fibers in the optic nerve is discussed in relation to the possible conservation of a single ... and in fibers in the nerve fiber layer and optic nerve. In the newborn retina, immunoreactivities for these two receptor ... and axons in the nerve fiber layer and optic nerve. A similar pattern of immunostaining persisted throughout the first ...
Clinical Pharmacology of Local Anesthetics - NYSORA
... drugs bind to produce nerve blocks has been cloned and mutated. This chapter focuses on mechanisms of anesthesia and toxicity, ... Unmyelinated fibers are relatively resistant to LAs, despite their smaller diameter, due to dispersal of Na channels throughout ... Both normal conduction and the way in which LAs inhibit conduction differ between myelinated and unmyelinated nerve fibers. ... fibers at lower concentrations than are required to block larger fibers of the same type. As a group, unmyelinated fibers are ...
Somaesthesia | Article about somaesthesia by The Free Dictionary
It receives input from small-diameter myelinated and unmyelinated peripheral nerve fibers carrying pain and temperature ... One major part, the lemniscal system, receives input from large-diameter myelinated peripheral nerve fibers (for example, those ... the sensory endings of certain peripheral nerve fibers) which differ not only in their sensitivities to different types of ...
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Grünenthal Group - Patients - Pain Management - Pain Glossary
C-fibers C-fibers are unmyelinated, thin nerve fibers with an axon diameter of approx. 1 µm and a conduction velocity of approx ... A delta fibers A delta fibers are slightly myelinated, thin nerve fibers with an axon diameter of 3-5 µm and a conduction ... Neuralgia Neuralgia (nerve pain) denotes a pain in the innervations area of a nerve or nerve root as the result of ... as well as peripheral nerve stimulation and transcutaneous nerve stimulation (TENS), in which the proximal nerve sections are ...
Afferent fibersPeripheral nervouAxon diameterFree nerve eNociceptiveNeuronSciatic nerveAction potentialsNociceptorsEfferent fibersSurrounding myelinatedConduction studiesCranial and spinal nervesMuscle fibersAfferentsMyelin sheathsThinly myelinatedNeuropathySpinal nervesEpidermal nerve fibersLarge diameter fibersBiopsyTypes of sensorySomatic sensorReceptorsProximalNeuropathic painAutonomic fibersDensitySensationOptic NerveElectrical stimulationSmall myelinatedDorsal RootSural nerveInnervate the skinImpulses from visceral organsAxonal
- They are afferent fibers, conveying input signals from the periphery to the central nervous system. (wikipedia.org)
- Sensory nerve fibers that carry a message to the central nervous system are labeled afferent fibers. (glowm.com)
- If afferent fibers are stimulated, alone or in combination with efferent fibers, a therapeutically effective amount of electrical stimulation is applied to activate afferent pathways in a manner approximating natural afferent activity. (patentsencyclopedia.com)
- The afferent fibers may be associated with primary receptors of muscle spindles, golgi tendon organs, secondary receptors of muscle spindles, joint receptors, touch receptors, and other types of mechanoreceptors and/or proprioceptors. (patentsencyclopedia.com)
- If efferent fibers are stimulated, alone or in combination with afferent fibers, a therapeutically effective amount of electrical stimulation is applied to activate intrafusal and/or extrafusal muscle fibers, which results in an indirect activation of afferent fibers associated therewith. (patentsencyclopedia.com)
- Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral nervous system. (wikipedia.org)
- The nervous system can be divided into the central nervous system, including the brain and spinal cord, and the peripheral nervous system, which includes each of the 31 paired spinal nerves and the 12 paired cranial nerves. (glowm.com)
- Since nociceptive afferent and sympathetic efferent fibers of the peripheral nervous system contribute to the pathophysiology of inflammation, and since a known side effect of gold therapy is a polyneuropathy, we tested the hypothesis that gold is toxic to small-diameter peripheral nerve fibers in the rat. (nih.gov)
- This is connected to the rest of the body by a route of nerves known as the peripheral nervous system. (cram.com)
- In the peripheral nervous system , each individual unmyelinated axon is cradled in Schwann cells peripheral glial cells cf. (mussenhealth.us)
- Obtain an understanding of the normal histological appearance of selected central and peripheral nervous system tissues namely spinal cord, cerebellum and peripheral nerve. (edu.au)
- Small fiber neuropathy occurs when the small fibers of the peripheral nervous system are damaged. (healthfitnessseek.com)
- A delta fibers A delta fibers are slightly myelinated, thin nerve fibers with an axon diameter of 3-5 µm and a conduction velocity of approx. (grunenthal.com)
- Myelinated and unmyelinated fiber, endoneurial capillary morphology, and the presence and distribution of autophagy structures were comparable between groups at baseline, except for a smaller myelinated axon diameter in subjects with T2DM and IGT compared to NGT. (lu.se)
- Myelin sheath thickness positively correlated with the axon diameter. (elsevier.com)
- These observations support the belief that sensitivity to local anesthetics is inversely proportional to axon diameter. (asahq.org)
- [1,These well established clinical observations are consistent with the long-held belief that sensitivity to local anesthetics is inversely proportional to axon diameter (conduction velocity). (asahq.org)
Free nerve e7
- 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. (thefreedictionary.com)
- Our human body is equipped with c - unmyelinated and also c- slightly myelinated free nerve endings that function by transmitting both pain and itch. (her-motorcycle.com)
- Sensory nerve endings are divided into two groups morphologically: mechanoreceptors and free nerve endings (Fig. 1, inset). (scholarpedia.org)
- The first is that of persistent stimulation of free nerve endings at the site of injury with pain transmitted via the small diameter A delta and C fibers to the central somatosensory cortex. (parjournal.net)
- [ 5 ] Following nerve injury, the proximal free nerve endings are unmyelinated, and these small diameter fibers have increased electrical activity and are stimulated at lower thresholds. (parjournal.net)
- Feelings of deep pressure (from a poke, for instance) are generated from Pacinian corpuscles (the only other type of phasic tactile mechanoreceptor), which are located deeper in the dermis, and some free nerve endings. (meddic.jp)
- this is signalled exclusively by free nerve endings. (meddic.jp)
- Nociceptive information is transmitted from the periphery to the central nervous system (CNS) by thin myelinated Aδ fibers and unmyelinated, small-diameter C fibers ( 2 ). (sciencemag.org)
- Firing of the Aβ fibers activates the inhibitory interneuron, reducing the chances that the projection neuron will fire, even in the presence of a firing nociceptive fiber. (wikipedia.org)
- A subset of nociceptive nerve fibers that terminate in the skin, respond to one or more chemicals that make us itch. (her-motorcycle.com)
- Our laboratory is devoted to investigate the neurobiological aspects of nerve degeneration and its consequences of neuroapthic pain, particularly focusing on small myelinated and unmyelinated nociceptive nerves (small-fibers) and their central pathways. (ntu.edu.tw)
- These nerve fibers terminate in the skin and are responsible for the transmission of thermal and nociceptive stimuli. (ntu.edu.tw)
- A parallel focus in this laboratory is to use the previously described technique to diagnose human neuropathies involving small-diameter nociceptive nerves (small-fiber neuropathy). (ntu.edu.tw)
- The pain seems to be lessened when the area is rubbed because activation of nonnociceptive fibers inhibits the firing of nociceptive ones in the laminae (Kandel et al. (bionity.com)
- Wrap their processes around neuron fibers to produce insulating coverings called myelin sheaths. (studystack.com)
- 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. (wikipedia.org)
- This differentiated regulation occurs via mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. (physiology.org)
- Firing of C fibers inhibits the inhibitory interneuron (indirectly), increasing the chances that the projection neuron will fire. (wikipedia.org)
- An inhibitory connection may exist with Aβ and C fibers, which may form a synapse on the same projection neuron. (bionity.com)
- The Aβ fiber, on the other hand, forms an excitatory connection with the inhibitory interneuron, thus decreasing the projection neuron's chance of firing (like the C fiber, the Aβ fiber also has an excitatory connection on the projection neuron itself). (bionity.com)
- Thus, depending on the relative rates of firing of C and Aβ fibers, the firing of the nonnociceptive fiber may inhibit the firing of the projection neuron and the transmission of pain stimuli (Kandel et al. (bionity.com)
- A neuron is also called a nerve cell. (differencebetween.net)
- If we talk about unmyelinated neuron, this means the axon is not covered by this myelin sheath. (differencebetween.net)
- The junction between the terminal of a neuron and either another neuron or a muscle or gland cell, over which nerve impulses pass. (lumenlearning.com)
- Autonomic drugs: The release of transmitter from vesicles in the nerve ending require the entry of ------ into the neuron. (cram.com)
- And this first pathway that I described is a pathway that involves a type of neuron called an alpha, I'm sorry, called a type A delta neuron, or nerve fiber. (coursera.org)
- Metabotropic glutamate receptor 5 (mGluR5) protein increased after sciatic nerve section in ipsilateral L4 and L5 DRG neuronal profiles, with most of the increase occurring in myelinated A-fiber somata. (jneurosci.org)
- mGluR5 also increased in lamina II of the ipsilateral spinal cord and the proximal sciatic nerve stump in this model. (jneurosci.org)
- Interestingly, after partial sciatic nerve section, mGluR5 expression did not change in either L4 or L5 DRG neuronal profiles. (jneurosci.org)
- Both spinal nerve ligation and sciatic nerve partial section produced significant mechanical and thermal hyperalgesia and tactile allodynia. (jneurosci.org)
- After partial sciatic nerve section, the mGluR5-specific antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) had no effect on any of these behaviors. (jneurosci.org)
- a) Western blots of sciatic nerve lysates from P30 LKB1 fl/fl control and LKB1-SCKO mouse probed with the indicated antibodies shows marked reduction of LKB1 protein expression in the mutant. (nih.gov)
- Blue: DAPI, scale bars: 20 μm (c) Representative light and electron micrographs (bottom panel) of transverse sciatic nerve sections from LKB1 fl/fl control and LKB1-SCKO mice at the indicated ages. (nih.gov)
- d) Immunofluorescence of longitudinal frozen sciatic nerve (P21) sections using the indicated stage-specific markers shows marked increases in SCs expressing Oct6, Sox2 (arrows), and Egr2 in LKB1-SCKO nerves as compared to LKB1 fl/fl control nerves, while there is no difference in the number of S100-positive SCs. (nih.gov)
- We investigated the effects of treadmill training (10 weeks) on hindlimb motor function and nerve morphometric parameters in diabetic rats submitted to sciatic nerve crush. (scielo.br)
- diabetic with sciatic nerve crush or trained diabetic with sciatic nerve crush. (scielo.br)
- Hindlimb motor function was evaluated weekly by assessing sciatic functional indices, and the proximal and distal portions of the sciatic nerve were used for morphometric analysis. (scielo.br)
- The non-diabetic with sciatic nerve crush, trained non-diabetic with sciatic nerve crush, diabetic with sciatic nerve crush and trained diabetic with sciatic nerve crush groups showed normal sciatic functional index from the 4th,4th,9th and 7th week post-injury, respectively. (scielo.br)
- Morphometric alterations in the proximal nerve portion of the diabetic with sciatic nerve crush and non-diabetic with sciatic nerve crush groups were either prevented or reverted to values similar to the non-diabetic group by treadmill training. (scielo.br)
- Diabetic condition promoted delay in sciatic nerve regeneration. (scielo.br)
- Longitudinal section of fiber bundles from the sciatic nerve after staining the myelin sheaths black using osmium tetroxide. (mussenhealth.us)
- In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma. (wikipedia.org)
- Alle H, Roth A, Geiger JRP: Energy-Efficient Action Potentials in Hippocampal Mossy Fibers. (biomedcentral.com)
- 1. A method comprising the step of: stimulating afferent nerve fibers in a predetermined manner to generate a stochastic response of action potentials in the nerve fibers in an animal to reduce a perception of pain by the animal. (patentsencyclopedia.com)
- wherein the predetermined manner of stimulation of the afferent nerve fibers comprises the application of electrical stimulation to the afferent nerve fibers, wherein the electrical stimulation comprises a stimulation parameter derived from the characteristic of the responsive action potentials. (patentsencyclopedia.com)
- C fiber receptors include: C fiber nociceptors responsible for the second, burning pain C fiber warming specific receptors responsible for warmth ultra-slow histamine-selective C fibers responsible for itch tactile C fibers sensual touch includes CT fibres, also known as C low-threshold mechanoreceptors (CLTM), which are unmyelinated afferents found in human hairy skin, and have a low mechanical threshold (wikipedia.org)
- Capsaicin-sensitive nerves are nociceptors that give rise to small diameter, unmyelinated C fibers (rarely, Ad fibers). (aafp.org)
- Tests that are used to directly investigate the integrity of the somatic innervation of the pelvic floor muscles and urinary and anal sphincters include electromyography (EMG), nerve conduction studies such as the pudendal nerve terminal motor latency (PNTML), and the electrophysiologic evaluation of the sacral reflexes. (glowm.com)
- This chapter reviews normal pelvic floor neuroanatomy, discusses the clinical evaluation of sacral nervous system, and reviews the common neurophysiologic tests used to investigate pelvic floor dysfunction, including EMG, nerve conduction studies, and sacral reflex studies. (glowm.com)
- 10 The diagnosis of small fiber neuropathy with traditional methods including nerve conduction studies is difficult as small fibers are undetectable. (podiatrytoday.com)
- Thus study aims to characterize the local, nerve-specific effects of acupuncture on the median and ulnar nerves in the forearm, using nerve conduction studies and quantitative sensory test. (bioportfolio.com)
- We aimed to evaluate nerve conduction studies and gastrocnemius H reflex responses in rheumatoid arthritis (RA) patients and compared to the healthy adult subjects. (bioportfolio.com)
- To evaluate the ultrasound findings of the median nerve in patients with clinical assigned carpal tunnel syndrome but normal nerve conduction studies. (bioportfolio.com)
- EMG/NCS (nerve conduction studies) measures only the faster (large nerves) and does not exclude the possibility of small fiber neuropathy if it is normal. (feetdoc.com)
Cranial and spinal nerves1
- Results show most fibers are unmyelinated, yet recent findings in experimental animals suggest many pulpal afferents originate from fibers that are myelinated at more proximal locations. (biomedcentral.com)
- This preponderance of unmyelinated fibers contrasts sharply with the results of other studies performed in experimental animals that suggest a more extensive innervation of the dental pulp by myelinated afferents (see Discussion). (biomedcentral.com)
- Primary afferents are classified by their diameter, degree of myelination, and conduction velocity. (mhmedical.com)
- Some tissues, such as the cornea, are innervated only by Aδ and C fiber afferents. (mhmedical.com)
- TY - JOUR T1 - Peripheral neuropathy in myotonic dystrophy: a nerve biopsy study. (unboundmedicine.com)
- Peripheral neuropathy is a common complication in patients with diabetes mellitus and consists of several clinical syndromes that affect motor, sensory and autonomic nerves. (scielo.br)
- 2,3 Accordingly, a useful animal model for studying nerve fiber regeneration in diabetic neuropathy is the combination of surgically-induced nerve injury with STZ-induced hyperglycemia in rats. (scielo.br)
- Moreover, nerve regeneration in diabetes is essential for the reversal of peripheral neuropathy and also promotes the recovery of nerves from injury as a result of acute nerve compression and entrapment. (scielo.br)
- This study was designed to assess whether the presence of autophagy-related structures was associated with sural nerve fiber pathology, and to investigate if endoneurial capillary pathology could predict the development of T2DM and neuropathy. (lu.se)
- Can Low-Level Laser Therapy Have An Impact For Small Fiber Neuropathy? (podiatrytoday.com)
- In addition to reviewing diagnostic testing for small fiber neuropathy and current treatments, these authors discuss recent study results for low-level laser therapy. (podiatrytoday.com)
- One would determine the classification of neuropathy by the fiber type that is directly affected. (podiatrytoday.com)
- 4 Clinical examination using electrodiagnostics, including electromyography (EMG) and nerve conduction velocity studies, help classify the type of neuropathy. (podiatrytoday.com)
- 7 Demyelinating neuropathy consistently presents with decreased nerve conduction velocity, prolonged terminal latency, temporal dispersion and blocked conduction. (podiatrytoday.com)
- The clinical presentation of individuals with small fiber neuropathy includes pain, paresthesias, loss of two-point discrimination, loss of thermal perception, xerosis and sometimes diminished Achilles deep tendon reflex and loss of the superficial reflexes. (podiatrytoday.com)
- Therefore, the diagnosis of small fiber neuropathy often occurs as a result of positive sensory symptoms. (podiatrytoday.com)
- However, positive sensory symptoms are not associated with only small fiber neuropathy as pain is also a common symptom of large fiber disorders. (podiatrytoday.com)
- Patients with small fiber neuropathy may also present with negative symptoms including numbness, tightness and coldness. (podiatrytoday.com)
- The first signs of diabetic neuropathy typically result from small-diameter nerve fiber dysfunction. (bmj.com)
- This review synthesized the evidence for small-diameter nerve fiber neuropathy measured via quantitative sensory testing (QST) in patients with diabetes with and without painful and non-painful neuropathies. (bmj.com)
- [ 1 - 3 ] This categorization is broad and includes a range of etiologies such as trauma, lesions of the central nervous system, diabetic peripheral neuropathy, multiple sclerosis, and herpetic nerve lesions. (parjournal.net)
- The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy. (elsevier.com)
- Small fiber neuropathy (SFN) represents a subtype of peripheral neuropathies. (healthfitnessseek.com)
- Many patients diagnosed with small fiber neuropathy ask their physicians about their prognosis, and physicians are usually not sure about how. (healthfitnessseek.com)
- Etiology Of Diabetic Peripheral Neuropathy If you have diabetes, you likely know that it sometimes causes neuropathy or nerve damage. (healthfitnessseek.com)
- The symptoms of small fiber sensory neuropathy are primarily sensory in nature. (healthfitnessseek.com)
- I have been diagnosed with Small Fiber Neuropathy. (healthfitnessseek.com)
- Small fiber neuropathy constitutes a syndrome of peripheral nerve disorders. (healthfitnessseek.com)
- Symptoms of small fiber neuropathy typically start with burning feet and numb toes. (healthfitnessseek.com)
- Sure enough, that test, a biopsy of skin samples showing diminished numbers of nerves at various points along my legs, proved positive for small fiber peripheral neuropathy. (healthfitnessseek.com)
- A small fiber neuropathy occurs when damage to the peripheral nerves predominantly or entirely affects the small myelinated (Aδ) fibers or unmyelinated C. (healthfitnessseek.com)
- Small fiber peripheral neuropathy is a polyneuropathy that occurs from damage to small. (healthfitnessseek.com)
- Sensory symptoms of small fiber neuropathy are highly variable. (healthfitnessseek.com)
- The sensory symptoms of small-fiber neuropathy vary a great deal, but. (healthfitnessseek.com)
- Small fibre neuropathy is a type of neuropathy affecting small nerve fibres of the. (healthfitnessseek.com)
- EMGs can be used to detect abnormal electrical activity of muscle that can occur in many diseases and conditions, including muscular dystrophy, inflammation of muscles, pinched nerves and peripheral nerve damage or neuropathy. (feetdoc.com)
- Because the skin has a relatively consistent number (or density) of epidermal nerves at each anatomic site, and this density is consistent between different genders and age groups, a density below the normal curve is indicative of small fiber peripheral neuropathy. (feetdoc.com)
- Degenerative changes within epidermal nerves may be predictive of neuropathy prior to the onset of symptoms. (feetdoc.com)
Epidermal nerve fibers4
- The small (intra)epidermal nerve fibers (ENFs) now can be visualized with immunohistochemical techniques using the panaxonal marker anti-protein gene product 9.5 (PGP 9.5). (neurology.org)
- Normal means and ranges for the density of epidermal nerve fibers in a reference population have been established. (neurology.org)
- The density of epidermal nerve fibers decreases with age and is lower in men compared with women. (neurology.org)
- Virtually all epidermal nerve fibers are small fibers. (healthfitnessseek.com)
Large diameter fibers1
- The results of the nerve biopsy specimens suggested that the mitochondria are structurally abnormal in patients with MFN2 mutations. (nih.gov)
- Despite histologically significant loss of nerve fibers, the mitochondria were not distinguishable from diseased sural nerve biopsy specimens and healthy controls. (nih.gov)
- We examined sural nerve biopsy specimens from 42 patients with FAP ATTR Val30Met using electron microscopy, particularly focusing on the morphology of nerve microvascular endothelial cells. (biomedcentral.com)
- Epidermal nerve fiber density testing is the analysis of a 3mm punch biopsy of skin to quantify the number unmyelinated C‐fibers and myelinated A delta‐fibers within the epidermis (see description above). (feetdoc.com)
Types of sensory1
- Consists of nerve fibers that convey impulses to the CNS from sensory receptors t/o the body. (studystack.com)
- Capsaicin activates C fibers Vanilloid receptors, giving chili peppers a hot sensation. (wn.com)
- P2X3 receptors are preclinically well-validated targets, highly specific to unmyelinated, C fiber afferent nerves that have dense innervations in visceral organs, skin and joints. (drugs.com)
- Dr. Ford added, "A key advantage of targeting P2X3 receptors is that they have limited distribution beyond sensory nerves and no significant expression in the higher centers of the brain. (drugs.com)
- NE inhibits its own release at the noradrenergic nerve terminal through --------- receptors. (cram.com)
- Ach inhibits the release of NE from the noradrenergic nerve terminal by binding to --------- receptors. (cram.com)
- Dendrite: slender fiber extensions containing sensory receptors that conduct impulse toward soma (graded potentials short distance signals) Axon: single fiber extension that generate nerve impulses and conducts impulses away from soma. (healthdocbox.com)
- These algesic (pain-producing) chemicals usually act on receptors on the surface of nerve cells. (humankinetics.com)
- Endocytosis of other receptor tyrosine kinases, most notably receptors for nerve growth factor, serves a very different function. (tomhsiung.com)
- Meissner Corpuscle: 1 fiber: many receptors. (coursehero.com)
- Merkle Cell: 1 fiber: many receptors. (coursehero.com)
- 6. A method according to claim 1, wherein the afferent nerve fibers innervate neural receptors. (patentsencyclopedia.com)
- 8. A method according to claim 1, wherein the afferent nerve fibers are in neural communication with neural receptors and are stimulated at a location that is between the neural receptors and a central nervous system of the animal. (patentsencyclopedia.com)
- The nerve cell body, dendrites, and proximal part of the axon are within the CNS. (nysora.com)
- Treadmill training is able to accelerate hindlimb motor function recovery in diabetic injured rats and prevent or revert morphometric alterations in proximal nerve portions in non-diabetic and diabetic injured rats. (scielo.br)
- In a recent study in anaesthetized rats, we stimulated the pelvic nerve immediately proximal to the pelvic ganglion (Figure 1 ). (frontiersin.org)
- Damage or injury to nerve fibers causes neuropathic pain. (wikipedia.org)
- P2X3-containing fibers have been broadly implicated for treating chronic inflammatory, visceral and neuropathic pain. (drugs.com)
- In addition to the loss of sensations, the other major consequence of nerve injury is neuropathic pain. (ntu.edu.tw)
- The clinical manifestation of neuropathic pain is derived from the degeneration of large diameter or small diameter sensory nerves. (podiatrytoday.com)
- Somatic fibers innervate the skin and voluntary muscles whereas autonomic fibers innervate cardiac and smooth muscles. (podiatrytoday.com)
- In addition to the involvement of small somatic nerve fibers, researchers have also reported involvement of small autonomic fibers. (podiatrytoday.com)
- Most peripheral nerves are mixed and contain sensory and motor as well as autonomic fibers. (mhmedical.com)
- A study by Duchesne et al indicated that in addition to myelinated nerve fibers, small unmyelinated fibers are also involved in CMT-1A, with the authors finding significantly reduced intraepidermal nerve fiber density in patients with CMT-1A compared with healthy controls. (medscape.com)
- The myelinated fiber density was reduced in 11 of the 13 myotonic dystrophy patients, with preferential loss of large myelinated fibers. (unboundmedicine.com)
- Greater amyloid deposition was observed in early-onset cases than in late-onset cases, whereas reduced nerve fiber density was more conspicuous in late-onset cases than in early-onset cases. (biomedcentral.com)
- In the cross-section fiber density was highest in the naso-dorsal to the central part and lowest in the temporo-ventral part. (elsevier.com)
- However, when the retinal lesion was made in or around the central high density area, a non-retinotopic arrangement of the optic nerve fibers was suggested. (elsevier.com)
- The nerve fiber density within the human dental pulp is quite impressive [ 9 ] and multiple studies have characterized these fibers relative to the presence or absence of myelin with the use of the electron microscope. (biomedcentral.com)
- Because of their higher conduction velocity, Aδ fibers are responsible for the sensation of a quick shallow pain that is specific on one area, termed as first pain. (wikipedia.org)
- Large fiber sensory nerves or large fibers are responsible for the transmission of proprioception and vibration sensation. (podiatrytoday.com)
- This is a pilot study to define the time course, the incidence of sensation restoration and the improvement in nerve conduction in people with numbness by using topical geranium oil. (bioportfolio.com)
- The visual capacity of the common barn owl (Tyto alba) was studied by quantitative analysis of the retina and optic nerve. (nih.gov)
- It is characterized by optic nerve hypoplasia, pituitary gland hypoplasia, and midline brain abnormalities, including absence of septum pellucidum and corpus callosum dysgenesis. (bvsalud.org)
- CASE PRESENTATION: We report a case of a premature African newborn male baby born to nonconsanguineous parents who presented to our institution with agenesis of the septum pellucidum, unilateral optic nerve hypoplasia, and pituitary stalk hypoplasia. (bvsalud.org)
- Cross-section of a neonatal optic nerve. (nervenet.org)
- On the basis of light and electron microscopic observations of the cross-section, the total count of optic nerve fibers in the eastern chipmunk (Tamias Sibiricus asiaticus) was estimated to be 5.65 × 10 5 . (elsevier.com)
- A gross retinotopic organisation was verified among the optic nerve fibers in the cross-section after localised lesions by laser beam in the nasal and temporal periphery. (elsevier.com)
- The assertion that large-diameter nerve fibers have low thresholds and small-diameter fibers have high thresholds in response to electrical stimulation has been held in a nearly axiomatic regard in the field of neuromodulation and neuroprosthetics. (sciencemag.org)
- Electrical stimulation that suppresses "pain" signal conduction in peripheral nerves inhibits pain before these signals enter the CNS and diverge over multiple pathways. (sciencemag.org)
- 2000). In transcutaneous electrical stimulation (TENS), nonnociceptive fibers are selectively stimulated with electrodes in order to produce this effect and thereby lessen pain. (bionity.com)
- Another application of electrical stimulation of nerves is the treatment of radiating pain in the lower extremities by stimulating the sacral nerve roots at the bottom of the spinal cord [Paul F. WHITE, Shitong Li and Jen W. Chiu. (justia.com)
- Another example of electrical stimulation for treatment of medical conditions is vagus nerve stimulation (VNS, also known as vagal nerve stimulation). (justia.com)
- The dorsal root of spinal nerve (or posterior root of spinal nerve) is one of two "roots" which emerge from the spinal cord. (wikipedia.org)
- The dorsal root transmits sensory information, forming the afferent sensory root of a spinal nerve. (wikipedia.org)
- The lateral division of the dorsal root contains lightly myelinated and unmyelinated fibres of small diameter. (wikipedia.org)
- The medial division of the dorsal root contains myelinated fibres of larger diameter. (wikipedia.org)
- If the dorsal root of a spinal nerve were severed it would lead to numbness in certain areas of the body. (wikipedia.org)
- Sural nerve biopsies from 13 unselected myotonic dystrophy patients and 6 normal controls were studied morphometrically. (unboundmedicine.com)
- Patients and Methods: Sural nerve physiology and ultrastructural morphology were studied at baseline and 11 years later in subjects with normal glucose tolerance (NGT), IGT, and T2DM. (lu.se)
- Results: Subjects with T2DM had significantly lower sural nerve amplitude compared to subjects with NGT and IGT at baseline. (lu.se)
Impulses from visceral organs1
- Its thickness is directly related to conduction velocity, which increases with axonal diameter. (nysora.com)
- Usual pathologic alterations are axonal atrophy, demyelination, nerve fiber loss and disordered neural repair. (scielo.br)
- These may result in a conduction block to nerve impulses (due to MYELIN SHEATH dysfunction) or axonal loss. (bioportfolio.com)
- The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. (elsevier.com)