Motor Neurons: Neurons which activate MUSCLE CELLS.Motor Neuron Disease: Diseases characterized by a selective degeneration of the motor neurons of the spinal cord, brainstem, or motor cortex. Clinical subtypes are distinguished by the major site of degeneration. In AMYOTROPHIC LATERAL SCLEROSIS there is involvement of upper, lower, and brainstem motor neurons. In progressive muscular atrophy and related syndromes (see MUSCULAR ATROPHY, SPINAL) the motor neurons in the spinal cord are primarily affected. With progressive bulbar palsy (BULBAR PALSY, PROGRESSIVE), the initial degeneration occurs in the brainstem. In primary lateral sclerosis, the cortical neurons are affected in isolation. (Adams et al., Principles of Neurology, 6th ed, p1089)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.Survival of Motor Neuron 1 Protein: A SMN complex protein that is essential for the function of the SMN protein complex. In humans the protein is encoded by a single gene found near the inversion telomere of a large inverted region of CHROMOSOME 5. Mutations in the gene coding for survival of motor neuron 1 protein may result in SPINAL MUSCULAR ATROPHIES OF CHILDHOOD.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Motor Cortex: Area of the FRONTAL LOBE concerned with primary motor control located in the dorsal PRECENTRAL GYRUS immediately anterior to the central sulcus. It is comprised of three areas: the primary motor cortex located on the anterior paracentral lobule on the medial surface of the brain; the premotor cortex located anterior to the primary motor cortex; and the supplementary motor area located on the midline surface of the hemisphere anterior to the primary motor cortex.Survival of Motor Neuron 2 Protein: A SMN complex protein that is closely-related to SURVIVAL OF MOTOR NEURON 1 PROTEIN. In humans, the protein is encoded by an often duplicated gene found near the inversion centromere of a large inverted region of CHROMOSOME 5.Evoked Potentials, Motor: The electrical response evoked in a muscle or motor nerve by electrical or magnetic stimulation. Common methods of stimulation are by transcranial electrical and TRANSCRANIAL MAGNETIC STIMULATION. It is often used for monitoring during neurosurgery.Amyotrophic Lateral Sclerosis: A degenerative disorder affecting upper MOTOR NEURONS in the brain and lower motor neurons in the brain stem and SPINAL CORD. Disease onset is usually after the age of 50 and the process is usually fatal within 3 to 6 years. Clinical manifestations include progressive weakness, atrophy, FASCICULATION, hyperreflexia, DYSARTHRIA, dysphagia, and eventual paralysis of respiratory function. Pathologic features include the replacement of motor neurons with fibrous ASTROCYTES and atrophy of anterior SPINAL NERVE ROOTS and corticospinal tracts. (From Adams et al., Principles of Neurology, 6th ed, pp1089-94)Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Muscular Atrophy, Spinal: A group of disorders marked by progressive degeneration of motor neurons in the spinal cord resulting in weakness and muscular atrophy, usually without evidence of injury to the corticospinal tracts. Diseases in this category include Werdnig-Hoffmann disease and later onset SPINAL MUSCULAR ATROPHIES OF CHILDHOOD, most of which are hereditary. (Adams et al., Principles of Neurology, 6th ed, p1089)Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Axons: Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.SMN Complex Proteins: A complex of proteins that assemble the SNRNP CORE PROTEINS into a core structure that surrounds a highly conserved RNA sequence found in SMALL NUCLEAR RNA. They are found localized in the GEMINI OF COILED BODIES and in the CYTOPLASM. The SMN complex is named after the Survival of Motor Neuron Complex Protein 1, which is a critical component of the complex.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Nerve Tissue ProteinsMolecular Motor Proteins: Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).Electric Stimulation: Use of electric potential or currents to elicit biological responses.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.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.Neuromuscular Diseases: A general term encompassing lower MOTOR NEURON DISEASE; PERIPHERAL NERVOUS SYSTEM DISEASES; and certain MUSCULAR DISEASES. Manifestations include MUSCLE WEAKNESS; FASCICULATION; muscle ATROPHY; SPASM; MYOKYMIA; MUSCLE HYPERTONIA, myalgias, and MUSCLE HYPOTONIA.Ganglia, Invertebrate: Clusters of neuronal cell bodies in invertebrates. Invertebrate ganglia may also contain neuronal processes and non-neuronal supporting cells. Many invertebrate ganglia are favorable subjects for research because they have small numbers of functional neuronal types which can be identified from one animal to another.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.Interneurons: Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.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.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Cholinergic Neurons: Neurons whose primary neurotransmitter is ACETYLCHOLINE.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Aplysia: An opisthobranch mollusk of the order Anaspidea. It is used frequently in studies of nervous system development because of its large identifiable neurons. Aplysiatoxin and its derivatives are not biosynthesized by Aplysia, but acquired by ingestion of Lyngbya (seaweed) species.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Dopaminergic Neurons: Neurons whose primary neurotransmitter is DOPAMINE.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Anterior Horn Cells: MOTOR NEURONS in the anterior (ventral) horn of the SPINAL CORD which project to SKELETAL MUSCLES.Neuromuscular Junction: The synapse between a neuron and a muscle.Dendrites: Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.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.Bulbar Palsy, Progressive: A motor neuron disease marked by progressive weakness of the muscles innervated by cranial nerves of the lower brain stem. Clinical manifestations include dysarthria, dysphagia, facial weakness, tongue weakness, and fasciculations of the tongue and facial muscles. The adult form of the disease is marked initially by bulbar weakness which progresses to involve motor neurons throughout the neuroaxis. Eventually this condition may become indistinguishable from AMYOTROPHIC LATERAL SCLEROSIS. Fazio-Londe syndrome is an inherited form of this illness which occurs in children and young adults. (Adams et al., Principles of Neurology, 6th ed, p1091; Brain 1992 Dec;115(Pt 6):1889-1900)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.Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.GABAergic Neurons: Neurons whose primary neurotransmitter is GAMMA-AMINOBUTYRIC ACID.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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.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.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.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Animals, Newborn: Refers to animals in the period of time just after birth.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.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).Motor Skills Disorders: Marked impairments in the development of motor coordination such that the impairment interferes with activities of daily living. (From DSM-V)Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.Brain Stem: The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.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)Neuropeptides: Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Neural Conduction: The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.Choline O-Acetyltransferase: An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.Ganglia: Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.Grasshoppers: Plant-eating orthopterans having hindlegs adapted for jumping. There are two main families: Acrididae and Romaleidae. Some of the more common genera are: Melanoplus, the most common grasshopper; Conocephalus, the eastern meadow grasshopper; and Pterophylla, the true katydid.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.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)Locomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Central Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.Reaction Time: The time from the onset of a stimulus until a response is observed.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Behavior, Animal: The observable response an animal makes to any situation.Medulla Oblongata: The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.Excitatory Postsynaptic Potentials: Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.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.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.Mice, Inbred C57BLMuscle, 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.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Olfactory Receptor Neurons: Neurons in the OLFACTORY EPITHELIUM with proteins (RECEPTORS, ODORANT) that bind, and thus detect, odorants. These neurons send their DENDRITES to the surface of the epithelium with the odorant receptors residing in the apical non-motile cilia. Their unmyelinated AXONS synapse in the OLFACTORY BULB of the BRAIN.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.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)Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Leeches: Annelids of the class Hirudinea. Some species, the bloodsuckers, may become temporarily parasitic upon animals, including man. Medicinal leeches (HIRUDO MEDICINALIS) have been used therapeutically for drawing blood since ancient times.Cyclic AMP Response Element-Binding Protein: A protein that has been shown to function as a calcium-regulated transcription factor as well as a substrate for depolarization-activated CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASES. This protein functions to integrate both calcium and cAMP signals.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.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.Muscles: Contractile tissue that produces movement in animals.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.Rhombencephalon: The posterior of the three primitive cerebral vesicles of an embryonic brain. It consists of myelencephalon, metencephalon, and isthmus rhombencephali from which develop the major BRAIN STEM components, such as MEDULLA OBLONGATA from the myelencephalon, CEREBELLUM and PONS from the metencephalon, with the expanded cavity forming the FOURTH VENTRICLE.Paralysis: A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Pyramidal Cells: Projection neurons in the CEREBRAL CORTEX and the HIPPOCAMPUS. Pyramidal cells have a pyramid-shaped soma with the apex and an apical dendrite pointed toward the pial surface and other dendrites and an axon emerging from the base. The axons may have local collaterals but also project outside their cortical region.Spinal Muscular Atrophies of Childhood: A group of recessively inherited diseases that feature progressive muscular atrophy and hypotonia. They are classified as type I (Werdnig-Hoffman disease), type II (intermediate form), and type III (Kugelberg-Welander disease). Type I is fatal in infancy, type II has a late infantile onset and is associated with survival into the second or third decade. Type III has its onset in childhood, and is slowly progressive. (J Med Genet 1996 Apr:33(4):281-3)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.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.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.Astrocytes: A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.Neurogenesis: Formation of NEURONS which involves the differentiation and division of STEM CELLS in which one or both of the daughter cells become neurons.Periodicity: The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).Nerve Growth Factors: Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Mesencephalon: The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems.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.FMRFamide: A molluscan neuroactive peptide which induces a fast excitatory depolarizing response due to direct activation of amiloride-sensitive SODIUM CHANNELS. (From Nature 1995; 378(6558): 730-3)Serotonin: A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Neurites: In tissue culture, hairlike projections of neurons stimulated by growth factors and other molecules. These projections may go on to form a branched tree of dendrites or a single axon or they may be reabsorbed at a later stage of development. "Neurite" may refer to any filamentous or pointed outgrowth of an embryonal or tissue-culture neural cell.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Kinesin: A microtubule-associated mechanical adenosine triphosphatase, that uses the energy of ATP hydrolysis to move organelles along microtubules toward the plus end of the microtubule. The protein is found in squid axoplasm, optic lobes, and in bovine brain. Bovine kinesin is a heterotetramer composed of two heavy (120 kDa) and two light (62 kDa) chains. EC 3.6.1.-.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.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Recruitment, Neurophysiological: The spread of response if stimulation is prolonged. (Campbell's Psychiatric Dictionary, 8th ed.)Nervous System: The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)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.Cranial Nerves: Twelve pairs of nerves that carry general afferent, visceral afferent, special afferent, somatic efferent, and autonomic efferent fibers.Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Homeodomain Proteins: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.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.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.Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.RNA-Binding Proteins: Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.Serotonergic Neurons: Neurons whose primary neurotransmitter is SEROTONIN.Astacoidea: A superfamily of various freshwater CRUSTACEA, in the infraorder Astacidea, comprising the crayfish. Common genera include Astacus and Procambarus. Crayfish resemble lobsters, but are usually much smaller.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.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.Tyrosine 3-Monooxygenase: An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.Efferent Pathways: Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.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.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Neurotransmitter Agents: Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.LIM-Homeodomain Proteins: A subclass of LIM domain proteins that include an additional centrally-located homeodomain region that binds AT-rich sites on DNA. Many LIM-homeodomain proteins play a role as transcriptional regulators that direct cell fate.Caenorhabditis elegans Proteins: Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.Embryo, Mammalian: The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Myenteric Plexus: One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)Movement Disorders: Syndromes which feature DYSKINESIAS as a cardinal manifestation of the disease process. Included in this category are degenerative, hereditary, post-infectious, medication-induced, post-inflammatory, and post-traumatic conditions.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Brain-Derived Neurotrophic Factor: A member of the nerve growth factor family of trophic factors. In the brain BDNF has a trophic action on retinal, cholinergic, and dopaminergic neurons, and in the peripheral nervous system it acts on both motor and sensory neurons. (From Kendrew, The Encyclopedia of Molecular Biology, 1994)Pons: The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.Growth Cones: Bulbous enlargement of the growing tip of nerve axons and dendrites. They are crucial to neuronal development because of their pathfinding ability and their role in synaptogenesis.RNA-Binding Protein FUS: A multifunctional heterogeneous-nuclear ribonucleoprotein that may play a role in homologous DNA pairing and recombination. The N-terminal portion of protein is a potent transcriptional activator, while the C terminus is required for RNA binding. The name FUS refers to the fact that genetic recombination events result in fusion oncogene proteins (ONCOGENE PROTEINS, FUSION) that contain the N-terminal region of this protein. These fusion proteins have been found in myxoid liposarcoma (LIPOSARCOMA, MYXOID) and acute myeloid leukemia.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.Substantia Nigra: The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Proprioception: Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.Receptors, N-Methyl-D-Aspartate: A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Corpus Striatum: Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.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.Prosencephalon: The anterior of the three primitive cerebral vesicles of the embryonic brain arising from the NEURAL TUBE. It subdivides to form DIENCEPHALON and TELENCEPHALON. (Stedmans Medical Dictionary, 27th ed)Rotarod Performance Test: A performance test based on forced MOTOR ACTIVITY on a rotating rod, usually by a rodent. Parameters include the riding time (seconds) or endurance. Test is used to evaluate balance and coordination of the subjects, particular in experimental animal models for neurological disorders and drug effects.Neuroprotective Agents: Drugs intended to prevent damage to the brain or spinal cord from ischemia, stroke, convulsions, or trauma. Some must be administered before the event, but others may be effective for some time after. They act by a variety of mechanisms, but often directly or indirectly minimize the damage produced by endogenous excitatory amino acids.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Microelectrodes: Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Mice, Neurologic Mutants: Mice which carry mutant genes for neurologic defects or abnormalities.Excitatory Amino Acid Antagonists: Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Neurotoxins: Toxic substances from microorganisms, plants or animals that interfere with the functions of the nervous system. Most venoms contain neurotoxic substances. Myotoxins are included in this concept.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.Forelimb: A front limb of a quadruped. (The Random House College Dictionary, 1980)Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Nitrergic Neurons: Nerve cells where transmission is mediated by NITRIC OXIDE.Receptors, AMPA: A class of ionotropic glutamate receptors characterized by their affinity for the agonist AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid).Nephropidae: Family of large marine CRUSTACEA, in the order DECAPODA. These are called clawed lobsters because they bear pincers on the first three pairs of legs. The American lobster and Cape lobster in the genus Homarus are commonly used for food.Parkinson Disease: A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)Stilbamidines: STILBENES with AMIDINES attached.Spinal Cord Injuries: Penetrating and non-penetrating injuries to the spinal cord resulting from traumatic external forces (e.g., WOUNDS, GUNSHOT; WHIPLASH INJURIES; etc.).Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.GABA Antagonists: Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.Pyramidal Tracts: Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts.Motor Neurons, Gamma: Motor neurons which activate the contractile regions of intrafusal SKELETAL MUSCLE FIBERS, thus adjusting the sensitivity of the MUSCLE SPINDLES to stretch. Gamma motor neurons may be "static" or "dynamic" according to which aspect of responsiveness (or which fiber types) they regulate. The alpha and gamma motor neurons are often activated together (alpha gamma coactivation) which allows the spindles to contribute to the control of movement trajectories despite changes in muscle length.Electrophysiological Phenomena: The electrical properties, characteristics of living organisms, and the processes of organisms or their parts that are involved in generating and responding to electrical charges.Adrenergic Neurons: Neurons whose primary neurotransmitter is EPINEPHRINE.Rats, Transgenic: Laboratory rats that have been produced from a genetically manipulated rat EGG or rat EMBRYO, MAMMALIAN. They contain genes from another species.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).DEAD Box Protein 20: A multifunctional protein that is both a DEAD-box RNA helicase and a component of the SMN protein complex.N-Methylaspartate: An amino acid that, as the D-isomer, is the defining agonist for the NMDA receptor subtype of glutamate receptors (RECEPTORS, NMDA).Inclusion Bodies: A generic term for any circumscribed mass of foreign (e.g., lead or viruses) or metabolically inactive materials (e.g., ceroid or MALLORY BODIES), within the cytoplasm or nucleus of a cell. Inclusion bodies are in cells infected with certain filtrable viruses, observed especially in nerve, epithelial, or endothelial cells. (Stedman, 25th ed)Ganglia, Sympathetic: Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.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.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.Inhibitory Postsynaptic Potentials: Hyperpolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during NEUROTRANSMISSION. They are local changes which diminish responsiveness to excitatory signals.Denervation: The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.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.
Motor fibers injuries may involve lower motor neurons, sympathetic fibers, and or both. Assessment items include: Sensory ... Motor fibers that allow movement of skeletal muscle. Sympathetic fibers that innervate the skin and blood vessels of the four ... In assessment, sensory-motor defects may be mild, moderate, or severe. Damage to motor fibers results in paralysis of the ... Motor and sensory functions distal to the point of injury are completely lost over time leading to Wallerian Degeneration due ...
The medial rectus is innervated by motor neurons in the oculomotor nucleus and nerve. The refractive index of the eye's lens ... Ocular motor control neurons Neurons that are interposed between the afferent and efferent limbs of this circuit and include ... the efferent limb and the ocular motor neurons that are between the afferent and efferent limb. The afferent limb of the ... The oculomotor neurons functions to send its axons in the oculomotor nerve, to control the medial rectus, and converge the two ...
... generating skeletal movement and are innervated by alpha motor neurons. Alpha motor neuron Beta motor neuron Extrafusal muscle ... They are innervated by gamma motor neurons and beta motor neurons. It is by the sensory information from these two intrafusal ... They constitute the muscle spindle and are innervated by two axons, one sensory and one motor. Intrafusal muscle fibers are ... fiber Gamma motor neuron Type Ia sensory fiber Type II sensory fiber Casagrand, Janet (2008) Action and Movement: Spinal ...
The siphon is additionally innervated by about 30 peripheral motor neurons. Kandel and colleagues used preparations of Aplysia ... A stimulus to the siphon (weak or moderate) is mediated by abdominal ganglion (55%) and by peripheral motor neurons (45%) and ... In the abdominal ganglion has seven central motor neurons been found that also produce movements of the siphon. LDS1, LDS2, ... By using preparations of Aplysia californica six central motor neurons have been found in the abdominal ganglion that produce ...
... somatic efferent motor neurons innervate skeletal muscle, and are always excitatory. Visceral efferent neurons innervate smooth ... A neuroeffector junction is a site where a motor neuron releases a neurotransmitter to affect a target-non-neuronal-cell. This ... ICC are innervated and transmitters reach high enough concentration to activate post-junctional signaling pathways in ICC. If ... In skeletal muscles, the junctions are mostly of the same distance and size because they innervate such definite structures of ...
Research found that the CB1 receptor is expressed presynaptically by motor neurons that innervate visceral organs. Cannabinoid- ... CB1 is present in neurons of the enteric nervous system and in sensory terminals of vagal and spinal neurons in the ... Emerging data in the field also points to FAAH being expressed in postsynaptic neurons complementary to presynaptic neurons ... Neuron. 54 (5): 801-12. doi:10.1016/j.neuron.2007.05.020. PMC 2001295 . PMID 17553427. Bacci A, Huguenard JR, Prince DA (2004 ...
In the mature synapse each muscle fiber is innervated by one motor neuron. However, during development many of the fibers are ... Synaptic communication between neurons leads to the establishment of functional neural circuits that mediate sensory and motor ... CNTF: Ciliary neurotrophic factor is another protein that acts as a survival factor for motor neurons. CNTF acts via a receptor ... Initially he thought that the extra limb was inducing proliferation of motor neurons, but he and his colleagues later showed ...
They propagate in the spinal cord, the motor neurons and the set of muscle fibers they innervate. This results in a twitch ... Old adults show evidence that remaining motor units may become larger as motor units innervate collateral muscle fibers. In ... These decreases may be partially due to losses of alpha motor neurons. By the age of 70, these losses occur in both proximal ... Normal aging movement control in humans is about the changes in the muscles, motor neurons, nerves, sensory functions, gait, ...
The PRF descends the reticulospinal tract where it innervates motor neurons and spinal interneurons. It is the main auditory ... Nearly all neurons are stained for GABA, especially in the central part of the nucleus, and the remaining GABA negative cells ... A modest number of GABA-stained neurons are arranged in small groups, generally in the center of the nucleus, whereas glycine- ... Glycinergic axon terminals, on the other hand, are more finely localized, with the majority of recipient neurons located ...
There it helps to maintain an upright and balanced posture by stimulating extensor motor neurons in the legs. It also ... innervates muscles of the trunk, thus additionally aiding in body posture. The lateral vestibular nuclei receive input from ...
... affects all peripheral nerves including sensory neurons, motor neurons, but rarely affects the autonomic ... All the oculomotor muscles innervated by the third nerve may be affected, but those that control pupil size are usually well- ... Loss of motor function results in dorsiflexion, contractures of the toes, loss of the interosseous muscle function that leads ... Therefore, diabetic neuropathy can affect all organs and systems, as all are innervated. There are several distinct syndromes ...
The inferior gluteal nerve is the main motor neuron that innervates the gluteus maximus muscle. It is responsible for the ... The largest muscle of the posterior hip, gluteus maximus, is innervated by the inferior gluteal nerve. It branches out and then ... findings in inferior gluteal innervated muscles and eight of the ten also had abnormalities in superior gluteal innervated ...
The other branch innervates the inhibitory interneuron, which in turn innervates the alpha motor neuron that synapses onto the ... One branch innervates the alpha motor neuron that causes the homonymous muscle to contract, producing the reflex. ... However, if a "misfiring" of motor neurons occurs, causing simultaneous contraction of opposing muscles, a tear can occur. For ... Because the interneuron is inhibitory, it prevents the opposing alpha motor neuron from firing, thereby reducing the ...
Each alpha motor neuron and the extrafusal muscle fibers innervated by it make up a motor unit. The connection between the ... Intrafusal muscle fiber Type Ia sensory fiber Type II sensory fiber Alpha motor neuron Gamma motor neuron Beta motor neuron ... Extrafusal muscle fibers are the skeletal standard muscle fibers that are innervated by alpha motor neurons and generate ... which are innervated by sensory nerve endings in central noncontractile parts and by gamma motor neurons in contractile ends ...
A single motor neuron is able to innervate multiple muscle fibers, thereby causing the fibers to contract at the same time. ... The brain sends electrochemical signals through the nervous system to the motor neuron that innervates several muscle fibers. ... A neuromuscular junction is a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is the site ... The time between a stimulus to the motor nerve and the subsequent contraction of the innervated muscle is called the latent ...
A lower motor neuron exits to the sacral plexus exiting through the spinal levels L5-S2. From the sacral plexus, the lower ... The tibial nerve innervates the semitendinosus as well as the other hamstring muscles, the semimembranosus and biceps femoris. ... motor neuron travels down the sciatic nerve. The sciatic nerve branches into the deep fibular nerve and the tibial nerve. ...
Upper motor neuron damage will not lead to atrophy or fasciculations, but only weakness of the innervated muscles. When the ... The hypoglossal nerve (XII) is unique in that it is innervated from both the motor cortex of both hemispheres of the brain. ... Damage to the nerve at lower motor neuron level may lead to fasciculations or atrophy of the muscles of the tongue. The ... Bell's Palsy is the result of an idiopathic (unknown cause), unilateral lower motor neuron lesion of the facial nerve and is ...
These ganglia form the basis for the peripheral nervous system's (PNS) sensory and motor neurons that innervate various parts ... The axons of motor neurons and sensory neurons develop from the neural tube region and through each of successive somite's ... The confinement of the axons arising from the dorsal root ganglia (DRG), the neural crest cells and the motor neurons from ... Neurons, which form the elemental unit of the nervous system, receive messages from their dendrites, relay the information as ...
The inner circular layer is innervated by both excitatory and inhibitory motor neurons, while the outer longitudinal layer is ... The physical contractions of the smooth muscle cells can be caused by action potentials in efferent motor neurons of the ... These efferent motor neuronns of the enteric nervous system are cholinergic and adrenergic neurons. ... innervated by mainly excitatory neurons. These action potentials cause the smooth muscle cells to contract or relax, depending ...
The first has mixed sensory and motor nerves innervating swimmerets while the second has sensory and motor neurons that ... Each ganglion contains the body of one motor giant neuron (MoG), powerful and large bodied motor neurons whose projections ... It then excites the motor neurons in the fast extensor muscles while directly exciting an inhibitory neuron that prevents ... The paper stated that command neurons were neurons (or small sets of neurons) carrying the entire command signal for a natural ...
... transition to sideways-walking gaits in brachyurans was accompanied by a reduction in the number of motor neurons innervating ...
... of the condition results from neuronal plasticity associated with bladder afferents and motor neurons innervating the external ...
In cases of motor neuron neurapraxia, symptoms consist of flaccid paralysis of the muscles innervated by the injured nerve or ... Neurapraxia is a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due ... there must be a complete and relatively rapid recovery of motor and sensory function once nerve conduction has been restored; ...
... preferentially replicating in and destroying motor neurons within the spinal cord, brain stem, or motor cortex. This leads to ... When spinal neurons die, Wallerian degeneration takes place, leading to weakness of those muscles formerly innervated by the ... Terminal sprouting may generate a few significantly enlarged motor neurons doing work previously performed by as many as four ... One mechanism involved in recovery is nerve terminal sprouting, in which remaining brainstem and spinal cord motor neurons ...
At this point, the nerve signal will synapse from the upper motor neurons to the lower motor neurons. The signal will travel ... The femoral nerve innervates the quadriceps femoris, a fourth of which is the rectus femoris. When the rectus femoris receives ... The signal starts with the upper motor neurons carrying the signal from the precentral gyrus down through the internal capsule ... the primary motor area of the brain). These neurons send a nerve signal that is carried by the corticospinal tract down the ...
The motor part of the spindle is provided by motor neurons: up to a dozen gamma motor neurons and one or two beta motor neurons ... Fusimotor neurons are classified as static or dynamic according to the type of muscle fibers they innervate and their effects ... Gamma motor neurons supply only muscle fibres within the spindle, whereas beta motor neurons supply muscle fibres both within ... muscle fibres within the spindle by up to a dozen gamma motor neurons and to a lesser extent by one or two beta motor neurons[ ...
The distal subtype corresponds to cord lesions at either C5/6 or C6/7 that affect anterior horn cells innervating C7-T1 nerve ... motor neurone disease. Introduction. Compressive spinal cord lesions typically result in a combination of upper motor neurone ... motor neurone disease. This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 ... Isolated lower motor neurone weakness affecting the upper limbs due to a compressive cervical cord lesion was first reported by ...
Hox6 gene activity is required during two critical phases of motor neuron development: first as motor axons select a trajectory ... The establishment of connections between motor neurons and limb muscles is mediated through the actions of genes encoding Hox ... However, the specific requirements for Hox genes in motor neuron specification and patterns of muscle connectivity are poorly ... This work indicates that Hox proteins execute their critical functions in motor neurons through intrinsic modules that confer ...
Motor neurons with limb-innervating character in the cervical spinal cord are sculpted by apoptosis based on the Hox code in ... Motor neurons with limb-innervating character in the cervical spinal cord are sculpted by apoptosis based on the Hox code in ... Motor neurons with limb-innervating character in the cervical spinal cord are sculpted by apoptosis based on the Hox code in ... Motor neurons with limb-innervating character in the cervical spinal cord are sculpted by apoptosis based on the Hox code in ...
How many motor neurons innervate each muscle fiber?. * Q: Are business owners required to file a profit and loss form with ...
Preference in slow motor neurons innervating type I or IIa muscle fibers. Together they form a unique fingerprint. * Motor ... Reappraisal of VAChT-Cre : Preference in slow motor neurons innervating type I or IIa muscle fibers. / Misawa, Hidemi; Inomata ... Reappraisal of VAChT-Cre : Preference in slow motor neurons innervating type I or IIa muscle fibers. In: Genesis. 2016. ... title = "Reappraisal of VAChT-Cre: Preference in slow motor neurons innervating type I or IIa muscle fibers", ...
innervating synonyms, innervating pronunciation, innervating translation, English dictionary definition of innervating. tr.v. ... which then transmit the commands via further circuits to motor neurons innervating muscles.. Neurons in spinal cord send Cc of ... To accomplish joint movement, a muscle fiber receives a neural signal from an innervating alpha motor neuron.. Introduction to ... sup][1] Compared with those neurons innervating the distal muscles of limbs, LMNs innervating axial muscles, such as the ...
E, The RP1, -3, -4, -5, and the V-neurons innervate the ventral longitudinal muscles. F, Motorneurons innervating the ventral ... U motorneuron innervating muscle DO1; (B) the motorneuron that innervates muscle LT1. C, The motorneurons that innervate muscle ... NB 4-2 gives rise to the RP2 motorneuron that innervates muscle DA2 and a distinct set of two motorneurons that innervate ... The other motorneurons derived from NB 7-1 (the two mediolateral U neurons and the motorneurons that most likely innervate ...
... generating skeletal movement and are innervated by alpha motor neurons. Alpha motor neuron Beta motor neuron Extrafusal muscle ... They are innervated by gamma motor neurons and beta motor neurons. It is by the sensory information from these two intrafusal ... They constitute the muscle spindle and are innervated by two axons, one sensory and one motor. Intrafusal muscle fibers are ... fiber Gamma motor neuron Type Ia sensory fiber Type II sensory fiber Casagrand, Janet (2008) Action and Movement: Spinal ...
An alpha motor neuron and the muscle fibers it innervates is a motor unit. A motor neuron pool contains the cell bodies of all ... Such motor units are made up of a single motor neuron and the muscle fibers that it innervates." "Motor neurons themselves fall ... Small motor neurons innervate slow-twitch fibers; intermediate-sized motor neurons innervate fast-twitch, fatigue-resistant ... "Small motor neurons innervate slow-twitch fibers; intermediate-sized motor neurons innervate fast-twitch, fatigue-resistant ...
The trial demonstrated remarkable improvements in motor milestones and rates of survival in the patients. This review focuses ... is characterized by the deterioration of alpha motor neurons in the brainstem and spinal cord. Currently, there is no cure for ... Alpha motor neurons innervate the skeletal muscles; thus, degeneration of these neurons results in a myriad of symptoms that ... Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy. J Neurosci. 2012;32: ...
6. MOTOR:  Lower motor neuron in the area of the lesion eg. C5-6 that innervate biceps muscle. LMN  Corticospinal tract (UMN ... 9. Horner syndrome :  Lesion on sympathetic fibers which innervate the head region.  Preganglionic neuron : intermediolateral ... 7. Muscle paralysis:  LMN paralysis : LMN in the spinal cord at the level of the lesion (C3,4,5,6..)  C3-4 innervate ... horn of the T1 segment of the spinal cord  Postganglionics neuron: superior cervical ganglion  Pupillary constriction: due to ...
Motor fibers injuries may involve lower motor neurons, sympathetic fibers, and or both. Assessment items include: Sensory ... Motor fibers that allow movement of skeletal muscle. Sympathetic fibers that innervate the skin and blood vessels of the four ... In assessment, sensory-motor defects may be mild, moderate, or severe. Damage to motor fibers results in paralysis of the ... Motor and sensory functions distal to the point of injury are completely lost over time leading to Wallerian Degeneration due ...
Todays study investigated the central connections of electric motor neurons innervating Posted on May 14, 2019. by ... Todays study investigated the central connections of electric motor neurons innervating the thyroarytenoid laryngeal muscles ... Viral infection of neurons was discovered through immunocytochemical labeling from the green fluorescent Lac-Z or protein. ... In addition, to TR-701 inhibition confirm that only TA motorneurons were being infected initially, four animals were given PRV- ...
the supply of nerves to organs and tissues, which provides for... Explanation of innervate ... Find out information about innervate. The distribution of nerves to a part. The amount of nerve stimulation received by a part ... Each nucleus contains around 6,000-7,000 neurons, about half of which are somatic motor neurons that directly innervate the ... Because axons from the Para II neurons innervate the velar lobes, it was suggested that the ASO is also involved in regulating ...
Muscles innervated by somatic motor neurons of facial nerve Stapedius, stylohyoid, posterio belly of digastric, mimetic muscles ... Pregang cell bodies are in dorsal motor nucleus of 10 in medulla, pregang fibers pass in vagus nerve t o thorax and abdomen and ...
A 3D model of human skeletal muscle innervated with stem cell-derived motor neurons enables epsilon-subunit targeted myasthenic ... A 3D model of human skeletal muscle innervated with stem cell-derived motor neurons enables epsilon-subunit targeted myasthenic ... These junctions demonstrated many of the hallmarks of motor neuron innervated muscles, including localised calcium transients ... Can the system be used with other motor neuron subtypes (i.e. MMC vs. LMC) and/or other muscle subtypes? ...
Motor Neurons Innervating the Direct Flight Muscles. (A and B) fruGAL4 generates expression in a motor neuron innervating the ... C-N) Axonal morphology of the motor neurons innervating the mnDFMs. The anti-HRP::Cy3 conjugate was used to reveal the neuronal ... The colocalization of FruM and Dsx in a subset of neurons in the TN1 cluster (arrowheads) of dsx-expressing neurons in the Msg ... Sexually Dimorphic Neuron Numbers in the Mesothoracic Ganglion. (A) Mean number of nuclei expressing β-Gal per hemisegment (±SD ...
The result that motor neurons following TMR behaved in a similar way as naturally innervated motor neurons has direct ... The second experiment sampled the motor neuron pool physiologically innervating the BBR muscle, and the third the motor neuron ... We compared the behavior of motor neurons innervating their physiological muscle targets with motor neurons from the same ... the motor neurons innervating the FDI had stronger common input in the delta band than both the same pool of motor neurons ...
ones that are innervated and are receiving signals from one neuron. This is this ones motor neuron motor unit. Keep in mind, ... A motor unit is going to be a somatic motor neuron and the fibers that it ... somatic motor neuron, for all intents and purposes were also going to ... Were going to have the axon from the somatic motor neuron coming to contact ...
The conference from which this volume originated surveyed research and theory on motor control mechanisms in the head-neck ... Without adequate head movement control, efficient spatial orientation and motor responses to visual and auditory stimuli could ... sensory-motor system. It was held in Fontainbleau, France, from July 17-24, 1989. The book provides a broad panorama of ... Chapter 36 Organization of the Motor Nuclei Innervating Epaxial Muscles in the Neck and Back Yuriko Sugiuchi, and Yoshikazu ...
innervate & other commonly used words, phrases, & idioms in the English language. ✔ Learn more! ... innervate mean? Learn the definition of Enervate vs. ... This is actually innervated by motor neurons, which are ... Because enervate sounds somewhat similar to both energize and innervate, it is sometimes treated as if it were synonymous with ... Its near homophone innervate-which is usually used in biological contexts with regard to nerves, though its sometimes used ...
Proctolin-expressing peptidergic motor neurons that innervate the hindgut (Fig. 1M).. dMP2 neurons undergo segment-specific ... The dMP2 `interneurons are Proctolin-expressing peptidergic motor neurons that innervate the Drosophila hindgut. We recently ... Why would only anterior dMP2s undergo apoptosis at stage 17? Since dMP2 neurons are motor neurons that exit the VNC, we ... actually exit the VNC and innervate the hindgut (Fig. 1J-L). Given that most, if not all, Drosophila motor neurons show signs ...
Most alpha motor neurons innervate between 500-1000 fibers in a motor unit. Intrinsic hand muscles, however, have alpha motor ... T/F) Gamma motor neurons may cause contraction of intrafusal muscle fibers, bringing about secondary effects once the change in ... When the tension in a tendon becomes high enough to damage the muscle or bone, the alpha motor neurons to the muscle are ... Alpha motor neurons conduct impulses in the (Aα/Aβ/Aδ) range of conduction velocities. ...
... and thus produce different populations of motor neurons from these cells in only 14 days. This discovery, published in Nature ... leading to more rapid progress in understanding diseases of the motor system, such as infantile spinal amyotrophy or ... Biotechnology, will make it possible to expand the production process for these neurons, ... The motor neurons that innervate muscle fibres are essential for motor activity. Their degeneration in many diseases causes ...
  • An MR scan of the lower limb muscles showed fatty infiltration (a sign of either a primary myopathy or denervation) in the quadriceps, adductors and tibialis anterior but sparing the hamstrings, that is, predominantly L2, L3, L4 and L5 innervated muscles (see figure 2A,B ). (bmj.com)
  • It has long been recognised that compressive cervical cord lesions may present as isolated lower motor neurone weakness of the upper limbs, a syndrome termed cervical spondylotic amyotrophy. (bmj.com)
  • We describe two patients presenting with isolated lower motor neurone weakness of the lower limbs in association with a compressive cord lesion at T11/12, a condition we have termed thoracic spondylotic amyotrophy. (bmj.com)
  • Isolated lower motor neurone weakness affecting the upper limbs due to a compressive cervical cord lesion was first reported by Brain and colleagues 1 in 1952 and has since been termed cervical spondylotic amyotrophy. (bmj.com)
  • 1 We describe two patients presenting with slowly progressive isolated lower motor neurone weakness affecting the lower limbs in association with a compressive spinal cord lesion at T11/12. (bmj.com)
  • In the present study, we crossed VAChT-Cre lines with a reporter line, CAG-Syp/tdTomato, in which synaptophysin-tdTomato fusion proteins are efficiently sorted to axon terminals, making it possible to label both cell bodies and axon terminals of motor neurons. (elsevier.com)
  • Sink and Whitington (1991a) described the location of all embryonic motorneurons in the CNS but were unable to resolve individual central and peripheral projections. (jneurosci.org)
  • light stimulation of peripheral skin receptors may not activate nociceptive (i.e., pain) neurons of the spinal cord. (wikibooks.org)
  • In REEP1-deficient mice, these neurons showed reduced complexity of the peripheral ER upon ultrastructural analysis. (jci.org)
  • In particular, the present invention includes methods for treating various repetitive and/or injurious motor activity symptoms of certain obsessive compulsive disorders by peripheral administration of a Clostridial toxin. (google.es)
  • Whereas, the premotoneurons for the Vmo include the mesencephalic nucleus (Vmes) neurons that are primary afferents whose cell bodies are located in the brain. (nii.ac.jp)
  • Immunohistochemical tracing/labeling experiments on DRG neurons showed that, compared to putative reflex-connected urethral afferents, reflex-connected glans afferents had significantly more substance P (SP) immunoreactivity. (ufl.edu)
  • These afferents innervate the large ventral horseshoe neuropil (HN) in the core of each ganglion. (uncg.edu)
  • Furthermore, we discovered that some of the crayfish afferents innervate glomeruli within the HN. (uncg.edu)
  • Researchers at the Institute for Stem Cell Therapy and Exploration of Monogenic Diseases (I-Stem - Inserm/AFM/UEVE), in collaboration with CNRS and Paris Descartes University, have recently developed a new approach to better control the differentiation of human pluripotent stem cells, and thus produce different populations of motor neurons from these cells in only 14 days. (eurekalert.org)
  • However, the development and realisation of these clinical applications is often limited by the inability to obtain specialised cells such as motor neurons from human pluripotent stem cells in an efficient and targeted manner. (eurekalert.org)
  • Soft culture substrates improve the yield of functional motor neurons derived from human pluripotent stem cells. (nature.com)
  • The central nervous system has two distinct ways of controlling the force produced by a muscle through motor unit recruitment: spatial recruitment and temporal recruitment. (wikipedia.org)
  • While working in New York City in 1899, Bronislaw Onuf-Onufrowicz discovered this group of unique cells and originally identified it as "Group X." "Group X" was considered distinct by Onufrowicz because the cells were different in size from the surrounding neurons in the anterolateral group, suggesting that they were independent. (wikipedia.org)
  • The spinal cord consists of multiple neuronal cell types that are critical to motor control and arise from distinct progenitor domains in the developing neural tube. (pnas.org)
  • Next, using recent developments in Rabies virus retrograde tracing, I mapped the location of the motor neurons in the facial nucleus, finding two distinct neuron pools for the extrinsic (retractor) muscle Nasolabialis and the intrinsic (protractor) follicular muscle. (epfl.ch)
  • These distinct motor neuron populations received premotor input from different sources in the brainstem. (epfl.ch)
  • Single and dual retrograde neuronal tracing from the airways and esophagus revealed that distinct, but intermingled, subsets of neurons in the compact formation of the nucleus ambiguus (nAmb) innervate these two tissues. (pubmedcentralcanada.ca)
  • Defects in neural development can lead to malformations and a wide variety of sensory, motor, and cognitive impairments, including holoprosencephaly and other neurological disorders such as Rett syndrome, Down syndrome and intellectual disability. (wikipedia.org)
  • The neural plate is the source of the majority of neurons and glial cells of the CNS. (wikipedia.org)
  • Muscles are controlled by neural signals sent from the spinal cord by pools of motor neurons. (jneurosci.org)
  • At this juncture in our exploration of motor control, let's focus on one of the best studied paradigms for understanding the neural control of movement: the eye movement system. (coursera.org)
  • Spinal cord injury (SCI) significantly disrupts normal neural circuitry, leading to severe degradation of motor and sensory function. (pnas.org)
  • Single-cell RNAseq analysis confirmed CHX10 + cells within the differentiated population, which consisted primarily of neurons with some glial and neural progenitor cells. (pnas.org)
  • The findings appear counterintuitive, because an established hypothesis holds that in ALS, aka Lou Gehrig's disease, neural excitation produces excess glutamate that in turn damages motor neurons. (alzforum.org)
  • Previous research provides an incomplete picture of the brain nuclei that are directly connected with the neural gut-brain axis, and no studies have thoroughly assessed sensory-motor overlap in those nuclei. (unboundmedicine.com)
  • Our goal in this study was to comprehensively characterize the central sensory and motor circuitry associated with the neural gut-brain axis linked to a segment of the small intestine. (unboundmedicine.com)
  • This is the first study to exhaustively investigate the sensory-motor organization of the neural gut-brain axis, and is a step toward phenotyping the many central neuronal populations involved in GI control. (unboundmedicine.com)
  • TY - JOUR T1 - Central sensory-motor crosstalk in the neural gut-brain axis. (unboundmedicine.com)
  • Data-driven computational neural network models have been used to study mechanisms for generating the motor patterns for breathing and breathing related behaviors such as coughing. (frontiersin.org)
  • Two neural networks are the focus: the sonic-vocal basis of acoustic signaling ( Fig. 10.1 A ) and pectoral control of anterior appendages, fins, and forelimbs ( Fig. 10.1 B ). For context, we first briefly review vertebrate phylogeny and the ancestral "blueprint" for hindbrain motor phenotypes. (nap.edu)
  • Lamina IX is located predominantly in the medial aspect of the ventral horn, although there is some contribution to lamina IX from a collection of motor neurons located more laterally. (wikipedia.org)
  • Loss of the survival motor neuron gene ( SMN1 ) is responsible for spinal muscular atrophy (SMA), the most common inherited cause of infant mortality. (plos.org)
  • Based on the age of onset and disease severity, SMA has been classified into four main clinical types (I-IV) caused by homozygous loss or mutation of the Survival Motor Neuron 1 (SMN1) gene [ 2 ]. (plos.org)
  • The mouse lines have been used in various studies with selective genetic modifications in adult motor neurons. (elsevier.com)
  • Critically, the authors found that the system only worked when cells were grown in 3D culture, as their 2D counterparts failed to undergo the critical developmental switch in acetylcholine receptors that is a hallmark of mature adult motor neurons. (biologists.com)