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.
A pinkish-yellow portion of the midbrain situated in the rostral mesencephalic tegmentum. It receives a large projection from the contralateral half of the CEREBELLUM via the superior cerebellar peduncle and a projection from the ipsilateral MOTOR CORTEX.
A reflex found in normal infants consisting of dorsiflexion of the HALLUX and abduction of the other TOES in response to cutaneous stimulation of the plantar surface of the FOOT. In adults, it is used as a diagnostic criterion, and if present is a NEUROLOGIC MANIFESTATION of dysfunction in the CENTRAL NERVOUS SYSTEM.
Intraoperative computer-assisted 3D navigation and guidance system generally used in neurosurgery for tracking surgical tools and localize them with respect to the patient's 3D anatomy. The pre-operative diagnostic scan is used as a reference and is transferred onto the operative field during surgery.
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.
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)
Degeneration of distal aspects of a nerve axon following injury to the cell body or proximal portion of the axon. The process is characterized by fragmentation of the axon and its MYELIN SHEATH.
The 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.
A front limb of a quadruped. (The Random House College Dictionary, 1980)
A diagnostic technique that incorporates the measurement of molecular diffusion (such as water or metabolites) for tissue assessment by MRI. The degree of molecular movement can be measured by changes of apparent diffusion coefficient (ADC) with time, as reflected by tissue microstructure. Diffusion MRI has been used to study BRAIN ISCHEMIA and tumor response to treatment.
Absent or reduced sensitivity to cutaneous stimulation.
The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.
A general term referring to a mild to moderate degree of muscular weakness, occasionally used as a synonym for PARALYSIS (severe or complete loss of motor function). In the older literature, paresis often referred specifically to paretic neurosyphilis (see NEUROSYPHILIS). "General paresis" and "general paralysis" may still carry that connotation. Bilateral lower extremity paresis is referred to as PARAPARESIS.
A physical property showing different values in relation to the direction in or along which the measurement is made. The physical property may be with regard to thermal or electric conductivity or light refraction. In crystallography, it describes crystals whose index of refraction varies with the direction of the incident light. It is also called acolotropy and colotropy. The opposite of anisotropy is isotropy wherein the same values characterize the object when measured along axes in all directions.
Marked impairments in the development of motor coordination such that the impairment interferes with activities of daily living. (From DSM-V)
Neurons which activate MUSCLE CELLS.
An abnormal response to a stimulus applied to the sensory components of the nervous system. This may take the form of increased, decreased, or absent reflexes.
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.
Subjective cutaneous sensations (e.g., cold, warmth, tingling, pressure, etc.) that are experienced spontaneously in the absence of stimulation.
Use of electric potential or currents to elicit biological responses.
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)
A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
Recording of the changes in electric potential of muscle by means of surface or needle electrodes.
A species of the genus MACACA which inhabits Malaya, Sumatra, and Borneo. It is one of the most arboreal species of Macaca. The tail is short and untwisted.
The region of the upper limb between the metacarpus and the FOREARM.
A nervous tissue specific protein which is highly expressed in NEURONS during development and NERVE REGENERATION. It has been implicated in neurite outgrowth, long-term potentiation, SIGNAL TRANSDUCTION, and NEUROTRANSMITTER release. (From Neurotoxicology 1994;15(1):41-7) It is also a substrate of PROTEIN KINASE C.
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.
A region extending from the PONS & MEDULLA OBLONGATA through the MESENCEPHALON, characterized by a diversity of neurons of various sizes and shapes, arranged in different aggregations and enmeshed in a complicated fiber network.
Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.
The use of diffusion ANISOTROPY data from diffusion magnetic resonance imaging results to construct images based on the direction of the faster diffusing molecules.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The 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.
Pathologic conditions which feature SPINAL CORD damage or dysfunction, including disorders involving the meninges and perimeningeal spaces surrounding the spinal cord. Traumatic injuries, vascular diseases, infections, and inflammatory/autoimmune processes may affect the spinal cord.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
The function of opposing or restraining the excitation of neurons or their target excitable cells.
Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).
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.
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.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
The duct which coveys URINE from the pelvis of the KIDNEY through the URETERS, BLADDER, and URETHRA.
Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.
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.
Force exerted when gripping or grasping.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
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.
Assessment of sensory and motor responses and reflexes that is used to determine impairment of the nervous system.
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.
Neural tracts connecting one part of the nervous system with another.
Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.
The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.
The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.
Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.
The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
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.
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.
The time from the onset of a stimulus until a response is observed.
The physical activity of a human or an animal as a behavioral phenomenon.
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.
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.
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
Contractile tissue that produces movement in animals.

Spinal cord-evoked potentials and muscle responses evoked by transcranial magnetic stimulation in 10 awake human subjects. (1/997)

Transcranial magnetic stimulation (TCMS) causes leg muscle contractions, but the neural structures in the brain that are activated by TCMS and their relationship to these leg muscle responses are not clearly understood. To elucidate this, we concomitantly recorded leg muscle responses and thoracic spinal cord-evoked potentials (SCEPs) after TCMS for the first time in 10 awake, neurologically intact human subjects. In this report we provide evidence of direct and indirect activation of corticospinal neurons after TCMS. In three subjects, SCEP threshold (T) stimulus intensities recruited both the D wave (direct activation of corticospinal neurons) and the first I wave (I1, indirect activation of corticospinal neurons). In one subject, the D, I1, and I2 waves were recruited simultaneously, and in another subject, the I1 and I2 waves were recruited simultaneously. In the remaining five subjects, only the I1 wave was recruited first. More waves were recruited as the stimulus intensity increased. The presence of D and I waves in all subjects at low stimulus intensities verified that TCMS directly and indirectly activated corticospinal neurons supplying the lower extremities. Leg muscle responses were usually contingent on the SCEP containing at least four waves (D, I1, I2, and I3).  (+info)

A clinical study of motor evoked potentials using a triple stimulation technique. (2/997)

Amplitudes of motor evoked potentials (MEPs) are usually much smaller than those of motor responses to maximal peripheral nerve stimulation, and show marked variation between normal subjects and from one stimulus to another. Consequently, amplitude measurements have low sensitivity to detect central motor conduction failures due to the broad range of normal values. Since these characteristics are mostly due to varying desynchronization of the descending action potentials, causing different degrees of phase cancellation, we applied the recently developed triple stimulation technique (TST) to study corticospinal conduction to 489 abductor digiti minimi muscles of 271 unselected patients referred for possible corticospinal dysfunction. The TST allows resynchronization of the MEP, and thereby a quantification of the proportion of motor units activated by the transcranial stimulus. TST results were compared with those of conventional MEPs. In 212 of 489 sides, abnormal TST responses suggested conduction failure of various degrees. By contrast, conventional MEPs detected conduction failures in only 77 of 489 sides. The TST was therefore 2.75 times more sensitive than conventional MEPs in disclosing corticospinal conduction failures. When the results of the TST and conventional MEPs were combined, 225 sides were abnormal: 145 sides showed central conduction failure, 13 sides central conduction slowing and 67 sides both conduction failure and slowing. It is concluded that the TST is a valuable addition to the study of MEPs, since it improves detection and gives quantitative information on central conduction failure, an abnormality which appears to be much more frequent than conduction slowing. This new technique will be useful in following the natural course and the benefit of treatments in disorders affecting central motor conduction.  (+info)

Corticospinal excitability modulation to hand muscles during movement imagery. (3/997)

Motor evoked potentials (MEPs) to magnetic transcranial stimulation (TCS) were recorded from right abductor digiti minimi (ADM) and first dorsal interosseous (FDI) muscles, sharing the same peripheral innervation but engaged in two different motor demands. In seven healthy and trained subjects, the latencies, amplitudes and variability of MEPs were investigated under the following, randomly intermingled, conditions: full muscular and mental relaxation; mental simulation of selective index finger or little finger abduction; mental non-motor activity (arithmetical calculation); and real motor task (little and index finger abduction). The whole procedure was performed by continuous audiovisual monitoring of electromyographic 'silence' in the tested muscles. The maximal facilitatory effects (= latency shortening and amplitude increase) on MEPs were induced by the real motor task. An amplitude potentiation of MEPs in both tested muscles was present during non-motor mental activity, in comparison to basal values. A further amplitude potentiation, without latency shifts, was confined to the muscle acting as 'prime mover' for the mentally simulated movement, according to the motor program dispatched but not executed by the subject. Similar results were also found in the F-wave, showing that mental simulation affects spinal motoneuronal excitability as well, although -- due to the lack of MEP and F-wave latency shift -- the main effect takes place at cortical level. The study shows that movement imagery can focus specific facilitation on the prime-mover muscle for the mentally simulated movement. This is mainly evident on FDI muscle, which controls fingers (i.e. the index) with highly corticalized motor representation.  (+info)

Axon guidance of outgrowing corticospinal fibres in the rat. (4/997)

This review is concerned with the development of the rat corticospinal tract (CST). The CST is a long descending central pathway, restricted to mammals, which is involved both in motor and sensory control. The rat CST is a very useful model in experimental research on the development of fibre systems in mammals because of its postnatal outgrowth throughout the spinal cord as well as its experimental accessibility. Hence mechanisms underlying axon outgrowth and subsequent target cell finding can be studied relatively easily. In this respect the corticospinal tract forms an important example and model system for the better understanding of central nervous system development in general.  (+info)

Brief theta-burst stimulation induces a transcription-dependent late phase of LTP requiring cAMP in area CA1 of the mouse hippocampus. (5/997)

Memory storage in the mammalian brain can be divided into a short-term phase that is independent of new protein synthesis and a long-term phase that requires synthesis of new RNA and proteins. A cellular model for these two phases has emerged from studies of long-term potentiation (LTP) in the three major excitatory synaptic pathways in the hippocampus. One especially effective protocol for inducing robust and persistent LTP is "theta-burst" stimulation, which is designed to mimic the firing patterns of hippocampal neurons recorded during exploratory behavior in intact awake animals. Unlike LTP induced by non-theta tetanization regimens, little is known about the biochemical mechanisms underlying theta-burst LTP in the hippocampus. In the present study, we examined theta-burst LTP in the Schaffer collateral pathway. We found that 3 sec of theta-burst stimulation induced a robust and persistent potentiation (theta L-LTP) in mouse hippocampal slices. This theta L-LTP was dependent on NMDA receptor activation. The initial or early phase of theta-LTP did not require either protein or RNA synthesis and was independent of cAMP-dependent protein kinase (PKA) activation. In contrast, the late phase of theta-LTP required synthesis of proteins and RNA and was blocked by inhibitors of PKA. Prior induction of theta-LTP also occluded the potentiation elicited by chemical activation of PKA. Our results show that, like non-theta LTP, theta-induced LTP in area CA1 of the mouse hippocampus also involves transcription, translation, and PKA and suggest that cAMP-mediated gene transcription may be a common mechanism responsible for the late phases of LTP induced by both theta and non-theta patterns of stimulation.  (+info)

Reactive oxygen species mediate activity-dependent neuron-glia signaling in output fibers of the hippocampus. (6/997)

Nonsynaptic signaling is becoming increasingly appreciated in studies of activity-dependent changes in the nervous system. We investigated the types of neuronal activity that elicit nonsynaptic communication between neurons and glial cells in hippocampal output fibers. High-frequency, but not low-frequency, action potential firing in myelinated CA1 axons of the hippocampus resulted in increased phosphorylation of the oligodendrocyte-specific protein myelin basic protein (MBP). This change was blocked by tetrodotoxin, indicating that axonally generated action potentials were necessary to regulate the phosphorylation state of MBP. Furthermore, scavengers of the reactive oxygen species superoxide and hydrogen peroxide and nitric oxide synthase inhibitors prevented activation of this neuron-glia signaling pathway. These results indicate that, during periods of increased neuronal activity in area CA1 of the hippocampus, reactive oxygen and nitrogen species are generated, which diffuse to neighboring oligodendrocytes and result in post-translational modifications of MBP, a key structural protein in myelin. Thus, in addition to their well-known capacity for activity-dependent neuron-neuron signaling, hippocampal pyramidal neurons possess a mechanism for activity-dependent neuron-glia signaling.  (+info)

Inosine stimulates extensive axon collateral growth in the rat corticospinal tract after injury. (7/997)

The purine nucleoside inosine has been shown to induce axon outgrowth from primary neurons in culture through a direct intracellular mechanism. For this study, we investigated the effects of inosine in vivo by examining whether it would stimulate axon growth after a unilateral transection of the corticospinal tract. Inosine applied with a minipump to the rat sensorimotor cortex stimulated intact pyramidal cells to undergo extensive sprouting of their axons into the denervated spinal cord white matter and adjacent neuropil. Axon growth was visualized by anterograde tracing with biotinylated dextran amine and by immunohistochemistry with antibodies to GAP-43. Thus, inosine, a naturally occurring metabolite without known side effects, might help to restore essential circuitry after injury to the central nervous system.  (+info)

MR-revealed myelination in the cerebral corticospinal tract as a marker for Pelizaeus-Merzbacher's disease with proteolipid protein gene duplication. (8/997)

BACKGROUND AND PURPOSE: Pelizaeus-Merzbacher's disease (PMD) is caused by mutations in the proteolipid protein (PLP) gene. Recent studies have shown that an increased PLP dosage, resulting from total duplication of the PLP gene, invariably causes the classic form of PMD. The purpose of this study was to compare the MR findings of PMD attributable to PLP duplication with those of PMD arising from a missense mutation. METHODS: Seven patients with PMD, three with a PLP missense mutation in either exon 2 or 5 (patients 1-3), and four with PLP duplication (patient 4 having larger PLP duplication than patients 5-7) were clinically classified as having either the classic or connatal form of PMD. Cerebral MR images were obtained to analyze the presence of myelination and T1 and T2 shortening in the deep gray matter. Multiple MR studies were performed in six of the seven patients to analyze longitudinal changes. RESULTS: Four patients (patients 1-4) were classified as having connatal PMD, whereas the other three (patients 5-7) were classified as having classic PMD. Myelination in the cerebral corticospinal tract, optic radiation, and corpus callosum was observed in three cases of classic PMD with PLP duplication. In patient 4, myelination extended to the internal capsule, corona radiata, and centrum semiovale over a 3-year period. No myelination was observed in three PMD cases with a PLP point mutation. T2 shortening in the deep gray matter was recognized in all patients with PMD. CONCLUSION: The presence of myelination in the cerebral corticospinal tract with diffuse white matter hypomyelination on MR images could be a marker for PMD with PLP duplication. It is suggested that progression of myelination may be present in connatal PMD with large PLP duplication.  (+info)

The pyramidal tracts, also known as the corticospinal tracts, are bundles of nerve fibers that run through the brainstem and spinal cord, originating from the cerebral cortex. These tracts are responsible for transmitting motor signals from the brain to the muscles, enabling voluntary movement and control of the body.

The pyramidal tracts originate from the primary motor cortex in the frontal lobe of the brain and decussate (cross over) in the lower medulla oblongata before continuing down the spinal cord. The left pyramidal tract controls muscles on the right side of the body, while the right pyramidal tract controls muscles on the left side of the body.

Damage to the pyramidal tracts can result in various motor impairments, such as weakness or paralysis, spasticity, and loss of fine motor control, depending on the location and extent of the damage.

The red nucleus is a round-shaped collection of neurons located in the midbrain, specifically in the rostral part of the mesencephalon. It is called "red" due to its deep red color, which comes from the rich vascularization and numerous iron-containing red blood cells present in the region.

The red nucleus plays a crucial role in the motor system, primarily involved in controlling and coordinating movements, particularly on the contralateral side of the body. It is part of the rubrospinal tract, which descends from the red nucleus to the spinal cord and helps regulate fine motor movements and muscle tone.

There are two main types of neurons present in the red nucleus: magnocellular (large cells) and parvocellular (small cells). Magnocellular neurons form the rubrospinal tract, while parvocellular neurons project to the inferior olivary nucleus, which is part of the cerebellum. The connections between the red nucleus, cerebellum, and spinal cord allow for the integration and coordination of motor information and the execution of smooth movements.

Damage to the red nucleus can result in various motor impairments, such as ataxia (lack of muscle coordination), tremors, and weakness on the contralateral side of the body.

The Babinski reflex, also known as the plantar reflex, is a physiological response that originates from the spinal cord when the sole of the foot is stimulated. It is named after Joseph François Felix Babinski, a French neurologist who described it in 1896.

In a normal, healthy adult, this stimulation typically results in the downward flexion of the big toe and the fanning out of the other toes. However, in infants and young children, as well as in some individuals with certain neurological conditions, the opposite response may occur - the big toe extends upward (dorsiflexes) while the other toes fan out. This is known as the Babinski reflex and can be a sign of damage to the brain or spinal cord, particularly to the nerve pathways that run from the cortex to the spinal cord.

It's important to note that the presence of an extensor plantar response (Babinski reflex) in adults is considered abnormal and may indicate a neurological disorder such as a brain injury, spinal cord injury, multiple sclerosis, or motor neuron disease. However, it's worth mentioning that certain medications, intoxication, or temporary conditions like sleep deprivation can also cause an abnormal plantar response, so further evaluation is necessary to confirm any diagnosis.

Neuronavigation is a surgical technique that uses imaging technology, such as MRI or CT scans, to create a 3D map of the patient's brain in real-time during surgery. This allows surgeons to accurately locate and navigate to specific areas of the brain with greater precision and less invasiveness, improving surgical outcomes and reducing the risk of complications.

The neuronavigation system typically consists of a computer workstation, tracking systems, and instruments that are equipped with sensors. The system is able to track the position and orientation of these instruments relative to the patient's brain, allowing the surgeon to visualize the location of the instruments on the 3D map in real-time.

Neuronavigation has become an essential tool in many neurosurgical procedures, including tumor resection, functional neurosurgery, and deep brain stimulation. It enables surgeons to perform more complex surgeries with increased safety and efficacy, ultimately improving the quality of care for patients undergoing these procedures.

The motor cortex is a region in the frontal lobe of the brain that is responsible for controlling voluntary movements. It is involved in planning, initiating, and executing movements of the limbs, body, and face. The motor cortex contains neurons called Betz cells, which have large cell bodies and are responsible for transmitting signals to the spinal cord to activate muscles. Damage to the motor cortex can result in various movement disorders such as hemiplegia or paralysis on one side of the body.

"Cat" is a common name that refers to various species of small carnivorous mammals that belong to the family Felidae. The domestic cat, also known as Felis catus or Felis silvestris catus, is a popular pet and companion animal. It is a subspecies of the wildcat, which is found in Europe, Africa, and Asia.

Domestic cats are often kept as pets because of their companionship, playful behavior, and ability to hunt vermin. They are also valued for their ability to provide emotional support and therapy to people. Cats are obligate carnivores, which means that they require a diet that consists mainly of meat to meet their nutritional needs.

Cats are known for their agility, sharp senses, and predatory instincts. They have retractable claws, which they use for hunting and self-defense. Cats also have a keen sense of smell, hearing, and vision, which allow them to detect prey and navigate their environment.

In medical terms, cats can be hosts to various parasites and diseases that can affect humans and other animals. Some common feline diseases include rabies, feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and toxoplasmosis. It is important for cat owners to keep their pets healthy and up-to-date on vaccinations and preventative treatments to protect both the cats and their human companions.

Wallerian degeneration is a process that occurs following damage to the axons of neurons (nerve cells). After an axon is severed or traumatically injured, it undergoes a series of changes including fragmentation and removal of the distal segment of the axon, which is the part that is separated from the cell body. This process is named after Augustus Waller, who first described it in 1850.

The degenerative changes in the distal axon are characterized by the breakdown of the axonal cytoskeleton, the loss of myelin sheath (the fatty insulating material that surrounds and protects the axon), and the infiltration of macrophages to clear away the debris. These events lead to the degeneration of the distal axon segment, which is necessary for successful regeneration of the injured nerve.

Wallerian degeneration is a crucial process in the nervous system's response to injury, as it enables the regrowth of axons and the reestablishment of connections between neurons. However, if the regenerative capacity of the neuron is insufficient or the environment is not conducive to growth, functional recovery may be impaired, leading to long-term neurological deficits.

The pons is a part of the brainstem that lies between the medulla oblongata and the midbrain. Its name comes from the Latin word "ponte" which means "bridge," as it serves to connect these two regions of the brainstem. The pons contains several important structures, including nerve fibers that carry signals between the cerebellum (the part of the brain responsible for coordinating muscle movements) and the rest of the nervous system. It also contains nuclei (clusters of neurons) that help regulate various functions such as respiration, sleep, and facial movements.

A forelimb is a term used in animal anatomy to refer to the upper limbs located in the front of the body, primarily involved in movement and manipulation of the environment. In humans, this would be equivalent to the arms, while in quadrupedal animals (those that move on four legs), it includes the structures that are comparable to both the arms and legs of humans, such as the front legs of dogs or the forepaws of cats. The bones that make up a typical forelimb include the humerus, radius, ulna, carpals, metacarpals, and phalanges.

Diffusion Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging technique that uses magnetic fields and radio waves to produce detailed images of the body's internal structures, particularly the brain and nervous system. In diffusion MRI, the movement of water molecules in biological tissues is measured and analyzed to generate contrast in the images based on the microstructural properties of the tissue.

Diffusion MRI is unique because it allows for the measurement of water diffusion in various directions, which can reveal important information about the organization and integrity of nerve fibers in the brain. This technique has been widely used in research and clinical settings to study a variety of neurological conditions, including stroke, traumatic brain injury, multiple sclerosis, and neurodegenerative diseases such as Alzheimer's disease.

In summary, diffusion MRI is a specialized type of MRI that measures the movement of water molecules in biological tissues to generate detailed images of the body's internal structures, particularly the brain and nervous system. It provides valuable information about the microstructural properties of tissues and has important applications in both research and clinical settings.

Hyperesthesia is a medical term that refers to an increased sensitivity to sensory stimuli, including touch, pain, or temperature. It can affect various parts of the body and can be caused by different conditions, such as nerve damage, multiple sclerosis, or complex regional pain syndrome. Hyperesthesia can manifest as a heightened awareness of sensations, which can be painful or uncomfortable, and may interfere with daily activities. It is essential to consult a healthcare professional for an accurate diagnosis and appropriate treatment if experiencing symptoms of hyperesthesia.

Neural conduction is the process by which electrical signals, known as action potentials, are transmitted along the axon of a neuron (nerve cell) to transmit information between different parts of the nervous system. This electrical impulse is generated by the movement of ions across the neuronal membrane, and it propagates down the length of the axon until it reaches the synapse, where it can then stimulate the release of neurotransmitters to communicate with other neurons or target cells. The speed of neural conduction can vary depending on factors such as the diameter of the axon, the presence of myelin sheaths (which act as insulation and allow for faster conduction), and the temperature of the environment.

Paresis is a medical term that refers to a partial loss of voluntary muscle function. It is often described as muscle weakness, and it can affect one or several parts of the body. Paresis can be caused by various conditions, including nerve damage, stroke, spinal cord injuries, multiple sclerosis, and infections like polio or botulism. The severity of paresis can range from mild to severe, depending on the underlying cause and the specific muscles involved. Treatment for paresis typically focuses on addressing the underlying condition causing it.

Anisotropy is a medical term that refers to the property of being directionally dependent, meaning that its properties or characteristics vary depending on the direction in which they are measured. In the context of medicine and biology, anisotropy can refer to various biological structures, tissues, or materials that exhibit different physical or chemical properties along different axes.

For example, certain types of collagen fibers in tendons and ligaments exhibit anisotropic behavior because they are stronger and stiffer when loaded along their long axis compared to being loaded perpendicular to it. Similarly, some brain tissues may show anisotropy due to the presence of nerve fibers that are organized in specific directions, leading to differences in electrical conductivity or diffusion properties depending on the orientation of the measurement.

Anisotropy is an important concept in various medical fields, including radiology, neurology, and materials science, as it can provide valuable information about the structure and function of biological tissues and help guide diagnostic and therapeutic interventions.

Motor skills disorders are conditions that affect a person's ability to perform coordinated movements. These movements can be simple, such as buttoning a shirt, or complex, such as playing a musical instrument. Motor skills disorders can make it difficult for a person to perform everyday activities and can impact their quality of life.

There are two main types of motor skills: fine motor skills and gross motor skills. Fine motor skills involve the small movements of the hands, fingers, and wrists, such as writing or using utensils. Gross motor skills involve larger movements of the arms, legs, and torso, such as crawling, walking, or running.

Motor skills disorders can affect either fine or gross motor skills, or both. Some common types of motor skills disorders include:

* Developmental coordination disorder (DCD): a condition that affects a child's ability to perform coordinated movements and is often diagnosed in early childhood. Children with DCD may have difficulty with tasks such as tying their shoes, buttoning their clothes, or using scissors.
* Cerebral palsy: a group of disorders that affect movement and muscle tone, caused by damage to the brain before, during, or after birth. Cerebral palsy can cause stiff or floppy muscles, uncontrolled movements, and difficulty with balance and coordination.
* Dyspraxia: a condition that affects a person's ability to plan and perform coordinated movements. People with dyspraxia may have difficulty with tasks such as writing, buttoning their clothes, or playing sports.
* Ataxia: a group of disorders that affect coordination and balance, caused by damage to the cerebellum (the part of the brain that controls movement). Ataxia can cause unsteady gait, poor coordination, and difficulty with fine motor tasks.

Motor skills disorders can be caused by a variety of factors, including genetics, injury, illness, or developmental delays. Treatment for motor skills disorders may include physical therapy, occupational therapy, speech therapy, and medication. In some cases, surgery may also be necessary to treat the underlying cause of the disorder.

Motor neurons are specialized nerve cells in the brain and spinal cord that play a crucial role in controlling voluntary muscle movements. They transmit electrical signals from the brain to the muscles, enabling us to perform actions such as walking, talking, and swallowing. There are two types of motor neurons: upper motor neurons, which originate in the brain's motor cortex and travel down to the brainstem and spinal cord; and lower motor neurons, which extend from the brainstem and spinal cord to the muscles. Damage or degeneration of these motor neurons can lead to various neurological disorders, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA).

An abnormal reflex in a medical context refers to an involuntary and exaggerated response or lack of response to a stimulus that is not expected in the normal physiological range. These responses can be indicative of underlying neurological disorders or damage to the nervous system. Examples include hyperreflexia (overactive reflexes) and hyporeflexia (underactive reflexes). The assessment of reflexes is an important part of a physical examination, as it can provide valuable information about the functioning of the nervous system.

Evoked potentials (EPs) are medical tests that measure the electrical activity in the brain or spinal cord in response to specific sensory stimuli, such as sight, sound, or touch. These tests are often used to help diagnose and monitor conditions that affect the nervous system, such as multiple sclerosis, brainstem tumors, and spinal cord injuries.

There are several types of EPs, including:

1. Visual Evoked Potentials (VEPs): These are used to assess the function of the visual pathway from the eyes to the back of the brain. A patient is typically asked to look at a patterned image or flashing light while electrodes placed on the scalp record the electrical responses.
2. Brainstem Auditory Evoked Potentials (BAEPs): These are used to evaluate the function of the auditory nerve and brainstem. Clicking sounds are presented to one or both ears, and electrodes placed on the scalp measure the response.
3. Somatosensory Evoked Potentials (SSEPs): These are used to assess the function of the peripheral nerves and spinal cord. Small electrical shocks are applied to a nerve at the wrist or ankle, and electrodes placed on the scalp record the response as it travels up the spinal cord to the brain.
4. Motor Evoked Potentials (MEPs): These are used to assess the function of the motor pathways in the brain and spinal cord. A magnetic or electrical stimulus is applied to the brain or spinal cord, and electrodes placed on a muscle measure the response as it travels down the motor pathway.

EPs can help identify abnormalities in the nervous system that may not be apparent through other diagnostic tests, such as imaging studies or clinical examinations. They are generally safe, non-invasive procedures with few risks or side effects.

Paresthesia is a medical term that describes an abnormal sensation such as tingling, numbness, prickling, or burning, usually in the hands, feet, arms, or legs. These sensations can occur without any obvious cause, often described as "pins and needles" or falling asleep in a limb. However, persistent paresthesia can be a sign of an underlying medical condition, such as nerve damage, diabetes, multiple sclerosis, or a vitamin deficiency. It is important to consult with a healthcare professional if experiencing persistent paresthesia to determine the cause and appropriate treatment.

Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.

In a medical context, electric stimulation may be used for various purposes such as:

1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.

It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.

A hindlimb, also known as a posterior limb, is one of the pair of extremities that are located distally to the trunk in tetrapods (four-legged vertebrates) and include mammals, birds, reptiles, and amphibians. In humans and other primates, hindlimbs are equivalent to the lower limbs, which consist of the thigh, leg, foot, and toes.

The primary function of hindlimbs is locomotion, allowing animals to move from one place to another. However, they also play a role in other activities such as balance, support, and communication. In humans, the hindlimbs are responsible for weight-bearing, standing, walking, running, and jumping.

In medical terminology, the term "hindlimb" is not commonly used to describe human anatomy. Instead, healthcare professionals use terms like lower limbs or lower extremities to refer to the same region of the body. However, in comparative anatomy and veterinary medicine, the term hindlimb is still widely used to describe the corresponding structures in non-human animals.

I'm sorry for any confusion, but "Macaca" is not a medical term. It is the name of a genus that includes several species of monkeys, commonly known as macaques. These primates are often used in biomedical research due to their similarities with humans in terms of genetics and physiology. If you have any questions related to medicine or health, I would be happy to try to help answer them.

An axon is a long, slender extension of a neuron (a type of nerve cell) that conducts electrical impulses (nerve impulses) away from the cell body to target cells, such as other neurons or muscle cells. Axons can vary in length from a few micrometers to over a meter long and are typically surrounded by a myelin sheath, which helps to insulate and protect the axon and allows for faster transmission of nerve impulses.

Axons play a critical role in the functioning of the nervous system, as they provide the means by which neurons communicate with one another and with other cells in the body. Damage to axons can result in serious neurological problems, such as those seen in spinal cord injuries or neurodegenerative diseases like multiple sclerosis.

Electromyography (EMG) is a medical diagnostic procedure that measures the electrical activity of skeletal muscles during contraction and at rest. It involves inserting a thin needle electrode into the muscle to record the electrical signals generated by the muscle fibers. These signals are then displayed on an oscilloscope and may be heard through a speaker.

EMG can help diagnose various neuromuscular disorders, such as muscle weakness, numbness, or pain, and can distinguish between muscle and nerve disorders. It is often used in conjunction with other diagnostic tests, such as nerve conduction studies, to provide a comprehensive evaluation of the nervous system.

EMG is typically performed by a neurologist or a physiatrist, and the procedure may cause some discomfort or pain, although this is usually minimal. The results of an EMG can help guide treatment decisions and monitor the progression of neuromuscular conditions over time.

"Macaca nemestrina," also known as the pig-tailed macaque, is not a medical term but a species name in biology. It refers to a specific species of monkey that is native to Southeast Asia. The pig-tailed macaque is a medium-sized monkey with a reddish-brown fur and a distinctive tail that resembles a pig's tail. They are omnivorous and live in social groups that can range from a few individuals to several hundred.

While "Macaca nemestrina" may not have a direct medical definition, these monkeys have been used as models in biomedical research due to their close genetic relationship with humans. Some studies involving pig-tailed macaques have contributed to our understanding of various human diseases and conditions, such as infectious diseases, neurological disorders, and reproductive health. However, it is important to note that the use of animals in research remains a controversial topic, and ethical considerations must be taken into account when conducting such studies.

A medical definition of the wrist is the complex joint that connects the forearm to the hand, composed of eight carpal bones arranged in two rows. The wrist allows for movement and flexibility in the hand, enabling us to perform various activities such as grasping, writing, and typing. It also provides stability and support for the hand during these movements. Additionally, numerous ligaments, tendons, and nerves pass through or near the wrist, making it susceptible to injuries and conditions like carpal tunnel syndrome.

GAP-43 protein, also known as growth-associated protein 43 or B-50, is a neuronal protein that is highly expressed during development and axonal regeneration. It is involved in the regulation of synaptic plasticity, nerve impulse transmission, and neurite outgrowth. GAP-43 is localized to the growth cones of growing axons and is thought to play a role in the guidance and navigation of axonal growth during development and regeneration. It is a member of the calcium/calmodulin-dependent protein kinase substrate family and undergoes phosphorylation by several protein kinases, including PKC (protein kinase C), which regulates its function. GAP-43 has been implicated in various neurological disorders, such as Alzheimer's disease, Parkinson's disease, and schizophrenia.

Movement disorders are a group of neurological conditions that affect the control and coordination of voluntary movements. These disorders can result from damage to or dysfunction of the cerebellum, basal ganglia, or other parts of the brain that regulate movement. Symptoms may include tremors, rigidity, bradykinesia (slowness of movement), akathisia (restlessness and inability to remain still), dystonia (sustained muscle contractions leading to abnormal postures), chorea (rapid, unpredictable movements), tics, and gait disturbances. Examples of movement disorders include Parkinson's disease, Huntington's disease, Tourette syndrome, and dystonic disorders.

The reticular formation is not a single structure but rather a complex network of interconnected neurons located in the brainstem, extending from the medulla oblongata through the pons and mesencephalon (midbrain) up to the diencephalon (thalamus and hypothalamus). It forms part of the reticular activating system, which is involved in regulating arousal, awareness, and sleep-wake cycles.

The reticular formation plays a crucial role in various functions such as:

1. Modulation of sensory input: The neurons in the reticular formation receive inputs from all senses (visual, auditory, tactile, etc.) and help filter and prioritize this information before it reaches higher cognitive areas.

2. Control of motor function: The reticular formation contributes to the regulation of muscle tone, posture, and locomotion by modulating the activity of motor neurons in the spinal cord.

3. Regulation of autonomic functions: The reticular formation is involved in controlling heart rate, blood pressure, respiration, and other visceral functions through its connections with the autonomic nervous system.

4. Consciousness and arousal: The ascending reticular activating system (ARAS) originates from the reticular formation and projects to the thalamus and cerebral cortex, where it helps maintain wakefulness and arousal. Damage to the ARAS can lead to coma or other states of altered consciousness.

5. Sleep-wake cycle regulation: The reticular formation contains cells that release neurotransmitters like histamine, serotonin, and orexin/hypocretin, which are essential for sleep-wake regulation. Dysfunction in these circuits has been implicated in various sleep disorders, such as narcolepsy and insomnia.

Urinary Tract Infections (UTIs) are defined as the presence of pathogenic microorganisms, typically bacteria, in any part of the urinary system, which includes the kidneys, ureters, bladder, and urethra, resulting in infection and inflammation. The majority of UTIs are caused by Escherichia coli (E. coli) bacteria, but other organisms such as Klebsiella, Proteus, Staphylococcus saprophyticus, and Enterococcus can also cause UTIs.

UTIs can be classified into two types based on the location of the infection:

1. Lower UTI or bladder infection (cystitis): This type of UTI affects the bladder and urethra. Symptoms may include a frequent and urgent need to urinate, pain or burning during urination, cloudy or strong-smelling urine, and discomfort in the lower abdomen or back.

2. Upper UTI or kidney infection (pyelonephritis): This type of UTI affects the kidneys and can be more severe than a bladder infection. Symptoms may include fever, chills, nausea, vomiting, and pain in the flanks or back.

UTIs are more common in women than men due to their shorter urethra, which makes it easier for bacteria to reach the bladder. Other risk factors for UTIs include sexual activity, use of diaphragms or spermicides, urinary catheterization, diabetes, and weakened immune systems.

UTIs are typically diagnosed through a urinalysis and urine culture to identify the causative organism and determine the appropriate antibiotic treatment. In some cases, imaging studies such as ultrasound or CT scan may be necessary to evaluate for any underlying abnormalities in the urinary tract.

Diffusion Tensor Imaging (DTI) is a type of magnetic resonance imaging (MRI) technique that allows for the measurement and visualization of water diffusion in biological tissues, particularly in the brain. DTI provides information about the microstructural organization and integrity of nerve fibers within the brain by measuring the directionality of water diffusion in the brain's white matter tracts.

In DTI, a tensor is used to describe the three-dimensional diffusion properties of water molecules in each voxel (three-dimensional pixel) of an MRI image. The tensor provides information about the magnitude and direction of water diffusion, which can be used to calculate various diffusion metrics such as fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). These metrics provide insights into the structural properties of nerve fibers, including their orientation, density, and integrity.

DTI has numerous clinical applications, such as in the diagnosis and monitoring of neurological disorders like multiple sclerosis, traumatic brain injury, and neurodegenerative diseases. It can also be used for presurgical planning to identify critical white matter tracts that need to be preserved during surgery.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

In the context of medicine and healthcare, "movement" refers to the act or process of changing physical location or position. It involves the contraction and relaxation of muscles, which allows for the joints to move and the body to be in motion. Movement can also refer to the ability of a patient to move a specific body part or limb, which is assessed during physical examinations. Additionally, "movement" can describe the progression or spread of a disease within the body.

Spinal cord diseases refer to a group of conditions that affect the spinal cord, which is a part of the central nervous system responsible for transmitting messages between the brain and the rest of the body. These diseases can cause damage to the spinal cord, leading to various symptoms such as muscle weakness, numbness, pain, bladder and bowel dysfunction, and difficulty with movement and coordination.

Spinal cord diseases can be congenital or acquired, and they can result from a variety of causes, including infections, injuries, tumors, degenerative conditions, autoimmune disorders, and genetic factors. Some examples of spinal cord diseases include multiple sclerosis, spina bifida, spinal cord injury, herniated discs, spinal stenosis, and motor neuron diseases such as amyotrophic lateral sclerosis (ALS).

The treatment for spinal cord diseases varies depending on the underlying cause and severity of the condition. Treatment options may include medication, physical therapy, surgery, and rehabilitation. In some cases, the damage to the spinal cord may be irreversible, leading to permanent disability or paralysis.

Myelinated nerve fibers are neuronal processes that are surrounded by a myelin sheath, a fatty insulating substance that is produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. This myelin sheath helps to increase the speed of electrical impulse transmission, also known as action potentials, along the nerve fiber. The myelin sheath has gaps called nodes of Ranvier where the electrical impulses can jump from one node to the next, which also contributes to the rapid conduction of signals. Myelinated nerve fibers are typically found in the peripheral nerves and the optic nerve, but not in the central nervous system (CNS) tracts that are located within the brain and spinal cord.

Brain mapping is a broad term that refers to the techniques used to understand the structure and function of the brain. It involves creating maps of the various cognitive, emotional, and behavioral processes in the brain by correlating these processes with physical locations or activities within the nervous system. Brain mapping can be accomplished through a variety of methods, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scans, electroencephalography (EEG), and others. These techniques allow researchers to observe which areas of the brain are active during different tasks or thoughts, helping to shed light on how the brain processes information and contributes to our experiences and behaviors. Brain mapping is an important area of research in neuroscience, with potential applications in the diagnosis and treatment of neurological and psychiatric disorders.

Neural inhibition is a process in the nervous system that decreases or prevents the activity of neurons (nerve cells) in order to regulate and control communication within the nervous system. It is a fundamental mechanism that allows for the balance of excitation and inhibition necessary for normal neural function. Inhibitory neurotransmitters, such as GABA (gamma-aminobutyric acid) and glycine, are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, reducing its likelihood of firing an action potential. This results in a decrease in neural activity and can have various effects depending on the specific neurons and brain regions involved. Neural inhibition is crucial for many functions including motor control, sensory processing, attention, memory, and emotional regulation.

The gastrointestinal (GI) tract, also known as the digestive tract, is a continuous tube that starts at the mouth and ends at the anus. It is responsible for ingesting, digesting, absorbing, and excreting food and waste materials. The GI tract includes the mouth, esophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, colon, rectum, anus), and accessory organs such as the liver, gallbladder, and pancreas. The primary function of this system is to process and extract nutrients from food while also protecting the body from harmful substances, pathogens, and toxins.

Functional laterality, in a medical context, refers to the preferential use or performance of one side of the body over the other for specific functions. This is often demonstrated in hand dominance, where an individual may be right-handed or left-handed, meaning they primarily use their right or left hand for tasks such as writing, eating, or throwing.

However, functional laterality can also apply to other bodily functions and structures, including the eyes (ocular dominance), ears (auditory dominance), or legs. It's important to note that functional laterality is not a strict binary concept; some individuals may exhibit mixed dominance or no strong preference for one side over the other.

In clinical settings, assessing functional laterality can be useful in diagnosing and treating various neurological conditions, such as stroke or traumatic brain injury, where understanding any resulting lateralized impairments can inform rehabilitation strategies.

The cerebral cortex is the outermost layer of the brain, characterized by its intricate folded structure and wrinkled appearance. It is a region of great importance as it plays a key role in higher cognitive functions such as perception, consciousness, thought, memory, language, and attention. The cerebral cortex is divided into two hemispheres, each containing four lobes: the frontal, parietal, temporal, and occipital lobes. These areas are responsible for different functions, with some regions specializing in sensory processing while others are involved in motor control or associative functions. The cerebral cortex is composed of gray matter, which contains neuronal cell bodies, and is covered by a layer of white matter that consists mainly of myelinated nerve fibers.

The spinal cord is a major part of the nervous system, extending from the brainstem and continuing down to the lower back. It is a slender, tubular bundle of nerve fibers (axons) and support cells (glial cells) that carries signals between the brain and the rest of the body. The spinal cord primarily serves as a conduit for motor information, which travels from the brain to the muscles, and sensory information, which travels from the body to the brain. It also contains neurons that can independently process and respond to information within the spinal cord without direct input from the brain.

The spinal cord is protected by the bony vertebral column (spine) and is divided into 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each segment corresponds to a specific region of the body and gives rise to pairs of spinal nerves that exit through the intervertebral foramina at each level.

The spinal cord is responsible for several vital functions, including:

1. Reflexes: Simple reflex actions, such as the withdrawal reflex when touching a hot surface, are mediated by the spinal cord without involving the brain.
2. Muscle control: The spinal cord carries motor signals from the brain to the muscles, enabling voluntary movement and muscle tone regulation.
3. Sensory perception: The spinal cord transmits sensory information, such as touch, temperature, pain, and vibration, from the body to the brain for processing and awareness.
4. Autonomic functions: The sympathetic and parasympathetic divisions of the autonomic nervous system originate in the thoracolumbar and sacral regions of the spinal cord, respectively, controlling involuntary physiological responses like heart rate, blood pressure, digestion, and respiration.

Damage to the spinal cord can result in various degrees of paralysis or loss of sensation below the level of injury, depending on the severity and location of the damage.

The urinary tract is a system in the body responsible for producing, storing, and eliminating urine. It includes two kidneys, two ureters, the bladder, and the urethra. The kidneys filter waste and excess fluids from the blood to produce urine, which then travels down the ureters into the bladder. When the bladder is full, urine is released through the urethra during urination. Any part of this system can become infected or inflamed, leading to conditions such as urinary tract infections (UTIs) or kidney stones.

Locomotion, in a medical context, refers to the ability to move independently and change location. It involves the coordinated movement of the muscles, bones, and nervous system that enables an individual to move from one place to another. This can include walking, running, jumping, or using assistive devices such as wheelchairs or crutches. Locomotion is a fundamental aspect of human mobility and is often assessed in medical evaluations to determine overall health and functioning.

Evoked potentials, motor, are a category of tests used in clinical neurophysiology to measure the electrical activity generated by the nervous system in response to a stimulus that specifically activates the motor pathways. These tests can help assess the integrity and function of the motor neurons, which are responsible for controlling voluntary muscle movements.

During a motor evoked potentials test, electrodes are placed on the scalp or directly on the surface of the brain or spinal cord. A stimulus is then applied to the motor cortex or peripheral nerves, causing the muscles to contract. The resulting electrical signals are recorded and analyzed to evaluate the conduction velocity, amplitude, and latency of the motor responses.

Motor evoked potentials tests can be useful in diagnosing various neurological conditions, such as multiple sclerosis, spinal cord injuries, and motor neuron diseases. They can also help monitor the progression of these conditions and assess the effectiveness of treatments.

Hand strength refers to the measure of force or power that an individual can generate using the muscles of the hand and forearm. It is often assessed through various tests, such as grip strength dynamometry, which measures the maximum force exerted by the hand when squeezing a device called a handgrip dynanometer. Hand strength is important for performing daily activities, maintaining independence, and can be indicative of overall health and well-being. Reduced hand strength may be associated with conditions such as neuromuscular disorders, arthritis, or injuries.

An action potential is a brief electrical signal that travels along the membrane of a nerve cell (neuron) or muscle cell. It is initiated by a rapid, localized change in the permeability of the cell membrane to specific ions, such as sodium and potassium, resulting in a rapid influx of sodium ions and a subsequent efflux of potassium ions. This ion movement causes a brief reversal of the electrical potential across the membrane, which is known as depolarization. The action potential then propagates along the cell membrane as a wave, allowing the electrical signal to be transmitted over long distances within the body. Action potentials play a crucial role in the communication and functioning of the nervous system and muscle tissue.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

A neurological examination is a series of tests used to evaluate the functioning of the nervous system, including both the central nervous system (the brain and spinal cord) and peripheral nervous system (the nerves that extend from the brain and spinal cord to the rest of the body). It is typically performed by a healthcare professional such as a neurologist or a primary care physician with specialized training in neurology.

During a neurological examination, the healthcare provider will assess various aspects of neurological function, including:

1. Mental status: This involves evaluating a person's level of consciousness, orientation, memory, and cognitive abilities.
2. Cranial nerves: There are 12 cranial nerves that control functions such as vision, hearing, smell, taste, and movement of the face and neck. The healthcare provider will test each of these nerves to ensure they are functioning properly.
3. Motor function: This involves assessing muscle strength, tone, coordination, and reflexes. The healthcare provider may ask the person to perform certain movements or tasks to evaluate these functions.
4. Sensory function: The healthcare provider will test a person's ability to feel different types of sensations, such as touch, pain, temperature, vibration, and proprioception (the sense of where your body is in space).
5. Coordination and balance: The healthcare provider may assess a person's ability to perform coordinated movements, such as touching their finger to their nose or walking heel-to-toe.
6. Reflexes: The healthcare provider will test various reflexes throughout the body using a reflex hammer.

The results of a neurological examination can help healthcare providers diagnose and monitor conditions that affect the nervous system, such as stroke, multiple sclerosis, Parkinson's disease, or peripheral neuropathy.

Interneurons are a type of neuron that is located entirely within the central nervous system (CNS), including the brain and spinal cord. They are called "inter" neurons because they connect and communicate with other nearby neurons, forming complex networks within the CNS. Interneurons receive input from sensory neurons and/or other interneurons and then send output signals to motor neurons or other interneurons.

Interneurons are responsible for processing information and modulating neural circuits in the CNS. They can have either excitatory or inhibitory effects on their target neurons, depending on the type of neurotransmitters they release. Excitatory interneurons release neurotransmitters such as glutamate that increase the likelihood of an action potential in the postsynaptic neuron, while inhibitory interneurons release neurotransmitters such as GABA (gamma-aminobutyric acid) or glycine that decrease the likelihood of an action potential.

Interneurons are diverse and can be classified based on various criteria, including their morphology, electrophysiological properties, neurochemical characteristics, and connectivity patterns. They play crucial roles in many aspects of CNS function, such as sensory processing, motor control, cognition, and emotion regulation. Dysfunction or damage to interneurons has been implicated in various neurological and psychiatric disorders, including epilepsy, Parkinson's disease, schizophrenia, and autism spectrum disorder.

Neural pathways, also known as nerve tracts or fasciculi, refer to the highly organized and specialized routes through which nerve impulses travel within the nervous system. These pathways are formed by groups of neurons (nerve cells) that are connected in a series, creating a continuous communication network for electrical signals to transmit information between different regions of the brain, spinal cord, and peripheral nerves.

Neural pathways can be classified into two main types: sensory (afferent) and motor (efferent). Sensory neural pathways carry sensory information from various receptors in the body (such as those for touch, temperature, pain, and vision) to the brain for processing. Motor neural pathways, on the other hand, transmit signals from the brain to the muscles and glands, controlling movements and other effector functions.

The formation of these neural pathways is crucial for normal nervous system function, as it enables efficient communication between different parts of the body and allows for complex behaviors, cognitive processes, and adaptive responses to internal and external stimuli.

Nerve degeneration, also known as neurodegeneration, is the progressive loss of structure and function of neurons, which can lead to cognitive decline, motor impairment, and various other symptoms. This process occurs due to a variety of factors, including genetics, environmental influences, and aging. It is a key feature in several neurological disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. The degeneration can affect any part of the nervous system, leading to different symptoms depending on the location and extent of the damage.

The brainstem is the lower part of the brain that connects to the spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls many vital functions such as heart rate, breathing, and blood pressure. It also serves as a relay center for sensory and motor information between the cerebral cortex and the rest of the body. Additionally, several cranial nerves originate from the brainstem, including those that control eye movements, facial movements, and hearing.

In medical terms, a hand is the part of the human body that is attached to the forearm and consists of the carpus (wrist), metacarpus, and phalanges. It is made up of 27 bones, along with muscles, tendons, ligaments, and other soft tissues. The hand is a highly specialized organ that is capable of performing a wide range of complex movements and functions, including grasping, holding, manipulating objects, and communicating through gestures. It is also richly innervated with sensory receptors that provide information about touch, temperature, pain, and proprioception (the sense of the position and movement of body parts).

Respiratory tract infections (RTIs) are infections that affect the respiratory system, which includes the nose, throat (pharynx), voice box (larynx), windpipe (trachea), bronchi, and lungs. These infections can be caused by viruses, bacteria, or, less commonly, fungi.

RTIs are classified into two categories based on their location: upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs). URTIs include infections of the nose, sinuses, throat, and larynx, such as the common cold, flu, laryngitis, and sinusitis. LRTIs involve the lower airways, including the bronchi and lungs, and can be more severe. Examples of LRTIs are pneumonia, bronchitis, and bronchiolitis.

Symptoms of RTIs depend on the location and cause of the infection but may include cough, congestion, runny nose, sore throat, difficulty breathing, wheezing, fever, fatigue, and chest pain. Treatment for RTIs varies depending on the severity and underlying cause of the infection. For viral infections, treatment typically involves supportive care to manage symptoms, while antibiotics may be prescribed for bacterial infections.

Cerebral infarction, also known as a "stroke" or "brain attack," is the sudden death of brain cells caused by the interruption of their blood supply. It is most commonly caused by a blockage in one of the blood vessels supplying the brain (an ischemic stroke), but can also result from a hemorrhage in or around the brain (a hemorrhagic stroke).

Ischemic strokes occur when a blood clot or other particle blocks a cerebral artery, cutting off blood flow to a part of the brain. The lack of oxygen and nutrients causes nearby brain cells to die. Hemorrhagic strokes occur when a weakened blood vessel ruptures, causing bleeding within or around the brain. This bleeding can put pressure on surrounding brain tissues, leading to cell death.

Symptoms of cerebral infarction depend on the location and extent of the affected brain tissue but may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; and severe headache with no known cause. Immediate medical attention is crucial for proper diagnosis and treatment to minimize potential long-term damage or disability.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Afferent neurons, also known as sensory neurons, are a type of nerve cell that conducts impulses or signals from peripheral receptors towards the central nervous system (CNS), which includes the brain and spinal cord. These neurons are responsible for transmitting sensory information such as touch, temperature, pain, sound, and light to the CNS for processing and interpretation. Afferent neurons have specialized receptor endings that detect changes in the environment and convert them into electrical signals, which are then transmitted to the CNS via synapses with other neurons. Once the signals reach the CNS, they are processed and integrated with other information to produce a response or reaction to the stimulus.

Computer-assisted image processing is a medical term that refers to the use of computer systems and specialized software to improve, analyze, and interpret medical images obtained through various imaging techniques such as X-ray, CT (computed tomography), MRI (magnetic resonance imaging), ultrasound, and others.

The process typically involves several steps, including image acquisition, enhancement, segmentation, restoration, and analysis. Image processing algorithms can be used to enhance the quality of medical images by adjusting contrast, brightness, and sharpness, as well as removing noise and artifacts that may interfere with accurate diagnosis. Segmentation techniques can be used to isolate specific regions or structures of interest within an image, allowing for more detailed analysis.

Computer-assisted image processing has numerous applications in medical imaging, including detection and characterization of lesions, tumors, and other abnormalities; assessment of organ function and morphology; and guidance of interventional procedures such as biopsies and surgeries. By automating and standardizing image analysis tasks, computer-assisted image processing can help to improve diagnostic accuracy, efficiency, and consistency, while reducing the potential for human error.

"Macaca mulatta" is the scientific name for the Rhesus macaque, a species of monkey that is native to South, Central, and Southeast Asia. They are often used in biomedical research due to their genetic similarity to humans.

A synapse is a structure in the nervous system that allows for the transmission of signals from one neuron (nerve cell) to another. It is the point where the axon terminal of one neuron meets the dendrite or cell body of another, and it is here that neurotransmitters are released and received. The synapse includes both the presynaptic and postsynaptic elements, as well as the cleft between them.

At the presynaptic side, an action potential travels down the axon and triggers the release of neurotransmitters into the synaptic cleft through exocytosis. These neurotransmitters then bind to receptors on the postsynaptic side, which can either excite or inhibit the receiving neuron. The strength of the signal between two neurons is determined by the number and efficiency of these synapses.

Synapses play a crucial role in the functioning of the nervous system, allowing for the integration and processing of information from various sources. They are also dynamic structures that can undergo changes in response to experience or injury, which has important implications for learning, memory, and recovery from neurological disorders.

Reaction time, in the context of medicine and physiology, refers to the time period between the presentation of a stimulus and the subsequent initiation of a response. This complex process involves the central nervous system, particularly the brain, which perceives the stimulus, processes it, and then sends signals to the appropriate muscles or glands to react.

There are different types of reaction times, including simple reaction time (responding to a single, expected stimulus) and choice reaction time (choosing an appropriate response from multiple possibilities). These measures can be used in clinical settings to assess various aspects of neurological function, such as cognitive processing speed, motor control, and alertness.

However, it is important to note that reaction times can be influenced by several factors, including age, fatigue, attention, and the use of certain medications or substances.

"Motor activity" is a general term used in the field of medicine and neuroscience to refer to any kind of physical movement or action that is generated by the body's motor system. The motor system includes the brain, spinal cord, nerves, and muscles that work together to produce movements such as walking, talking, reaching for an object, or even subtle actions like moving your eyes.

Motor activity can be voluntary, meaning it is initiated intentionally by the individual, or involuntary, meaning it is triggered automatically by the nervous system without conscious control. Examples of voluntary motor activity include deliberately lifting your arm or kicking a ball, while examples of involuntary motor activity include heartbeat, digestion, and reflex actions like jerking your hand away from a hot stove.

Abnormalities in motor activity can be a sign of neurological or muscular disorders, such as Parkinson's disease, cerebral palsy, or multiple sclerosis. Assessment of motor activity is often used in the diagnosis and treatment of these conditions.

Skeletal muscle, also known as striated or voluntary muscle, is a type of muscle that is attached to bones by tendons or aponeuroses and functions to produce movements and support the posture of the body. It is composed of long, multinucleated fibers that are arranged in parallel bundles and are characterized by alternating light and dark bands, giving them a striped appearance under a microscope. Skeletal muscle is under voluntary control, meaning that it is consciously activated through signals from the nervous system. It is responsible for activities such as walking, running, jumping, and lifting objects.

Synaptic transmission is the process by which a neuron communicates with another cell, such as another neuron or a muscle cell, across a junction called a synapse. It involves the release of neurotransmitters from the presynaptic terminal of the neuron, which then cross the synaptic cleft and bind to receptors on the postsynaptic cell, leading to changes in the electrical or chemical properties of the target cell. This process is critical for the transmission of signals within the nervous system and for controlling various physiological functions in the body.

Brain neoplasms, also known as brain tumors, are abnormal growths of cells within the brain. These growths can be benign (non-cancerous) or malignant (cancerous). Benign brain tumors typically grow slowly and do not spread to other parts of the body. However, they can still cause serious problems if they press on sensitive areas of the brain. Malignant brain tumors, on the other hand, are cancerous and can grow quickly, invading surrounding brain tissue and spreading to other parts of the brain or spinal cord.

Brain neoplasms can arise from various types of cells within the brain, including glial cells (which provide support and insulation for nerve cells), neurons (nerve cells that transmit signals in the brain), and meninges (the membranes that cover the brain and spinal cord). They can also result from the spread of cancer cells from other parts of the body, known as metastatic brain tumors.

Symptoms of brain neoplasms may vary depending on their size, location, and growth rate. Common symptoms include headaches, seizures, weakness or paralysis in the limbs, difficulty with balance and coordination, changes in speech or vision, confusion, memory loss, and changes in behavior or personality.

Treatment for brain neoplasms depends on several factors, including the type, size, location, and grade of the tumor, as well as the patient's age and overall health. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence and manage any long-term effects of treatment.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

Involvement of the pyramidal tract at any level leads to pyramidal signs. The myelination of the pyramidal fibres is incomplete ... The pyramidal tracts include both the corticobulbar tract and the corticospinal tract. These are aggregations of efferent nerve ... The pyramidal tracts definitively encompass the corticospinal tracts, and many authors also include the corticobulbar tracts. ... The corticospinal tract contains the axons of the pyramidal cells, the largest of which are the Betz cells, located in the ...
... indicate that the pyramidal tract is affected at some point in its course. Pyramidal tract dysfunction can lead ... The upper motor neurons from the central nervous system descend through the pyramidal tracts (i.e., corticospinal tracts), ... see video) Parkinsonian-Pyramidal syndrome (PPS) is a combination of both pyramidal and parkinsonian signs that manifest in ... Lohia, Akash; McKenzie, Juanette (January 2020). Neuroanatomy, Pyramidal Tract Lesions. Treasure Island (FL): StatPearls ...
Lassek, A.M. (1941). "The pyramidal tract of the monkey". J. Comp. Neurol. 74 (2): 193-202. doi:10.1002/cne.900740202. S2CID ... 30: 238-264.{{cite journal}}: CS1 maint: multiple names: authors list (link) Evarts, E.V. (1968). "Relation of pyramidal tract ... Precentral sulcus Central sulcus The motor tract. Corticospinal tract Motor cortex Cortical homunculus Upper motor neuron ... pyramidal decussation), the axons travel down the spinal cord as the lateral corticospinal tract. Fibers that do not cross over ...
Lassek, A.M. (1941). "The pyramidal tract of the monkey". J. Comp. Neurol. 74 (2): 193-202. doi:10.1002/cne.900740202. S2CID ... Heffner, R. & Masterton, B. (1975). "Variation in form of the pyramidal tract and its relationship to digital dexterity". Brain ...
Kalischer postulated a pyramidal tract in birds. He was also among the first to prove that striatal rather than cortical areas ...
This phenomenon is associated with pyramidal tract lesions with moderate spasticity. Mondofacto Dictionary (definition of ...
... along with other extra-pyramidal tracts including the vestibulospinal, tectospinal, and reticulospinal tracts. The tract is ... The rubrospinal tract is a part of the nervous system. It is a part of the lateral indirect extra-pyramidal tract. In the ... the rubrospinal tract can assume almost all the duties of the corticospinal tract when the corticospinal tract is lesioned.[ ... coursing adjacent to the lateral corticospinal tract. In humans, the rubrospinal tract is one of several major motor control ...
This is in contrast to symptoms originating from the pyramidal tracts.[citation needed] Neuroleptic malignant syndrome Rabbit ...
They are lost as the pyramidal tracts gain functionality with progressive myelination. They may reappear in adults or children ... because of low myelination of the corticospinal tracts. As these tracts develop to adult form, the flexion-reflex circuit is ... with loss of function of the pyramidal system due to a variety of reasons. However, with the advent of Amiel Tison method of ...
Pyramidal signs- Various signs that indicate a condition of the pyramidal tracts. Dementia- Occurs in approximately one-quarter ...
WK (1907): A case of primary systemic degeneration of the pyramidal tracts. (Spastic Paraplegia). German Journal of Neurology ...
... motor impulses from brain through pyramidal tract (27 min). PMF 5040 - PMF 5041 - PMF 5042 - PMF 5043 - PMF 5044 (1947) - ...
Pyramid visible at center.) Sketch of the brainstem, with the pyramidal tract visible in red, and pyramidal decussation labeled ... The medullary pyramids contain the motor fibers of the pyramidal tracts - the corticospinal and corticobulbar tracts. Whiplash ... These are the corticobulbar and corticospinal fibers that make up the pyramidal tracts. About 90% of these fibers leave the ... The other 10% of the fibers stay uncrossed in the anterior corticospinal tract. The pyramidal decussation marks the border ...
The roots form a pyramidal tract to hold the trunk. They commonly have many thick stilt roots near the base, which provide ...
Pyramidal tracts Extrapyramidal tracts Command neuron Reticular formation Lemon, Roger N. (July 21, 2008). "Descending Pathways ... pyramidal tracts, which originate in the motor cortex, and extrapyramidal tracts, which originate in the brainstem (see ... Their axons traverse the neck in connectives, or tracts, and output onto neurons in the spinal cord (vertebrates) or ventral ... An example of the latter is the reticulospinal tract, which contributes to the unconscious regulation of locomotion and posture ...
... injuries to the pyramidal tract above the medulla generally cause contralateral hemiparesis (weakness on the opposite side as ... sleep paralysis Movement of the body is primarily controlled by the pyramidal (or corticospinal) tract, a pathway of neurons ... A case report describes a patient with a congenitally uncrossed pyramidal tract, who developed right-sided hemiparesis after a ... "Ipsilateral hemiparesis after putaminal hemorrhage due to uncrossed pyramidal tract" (PDF). Neurology. 54 (9): 1801-5. doi: ...
More specifically, the pyramidal tract neurons (PTNs) were targeted for measurement. The primary frequency recorded was between ... Melanopsin encodes the day-night cycle to the suprachiasmatic nucleus (SCN) via the retinohypothalamic tract. The SCN evokes a ...
The corticospinal tract is one of the pyramidal tracts, the other being the corticobulbar tract. The corticospinal tract ... There are two divisions of the corticospinal tract, the lateral corticospinal tract and the anterior corticospinal tract. The ... After patients are lesioned in some part of the pyramidal tracts, they are paralyzed on the corresponding side of the body. ... Then both tracts pass through the brain stem, from the pons and then to the medulla. The corticospinal tract, along with the ...
The exception is the corticospinal tracts(pyramidal tracts) in the brainstem and sometimes spinal cord. The brain pathology of ... matter abnormalities are relatively confined to the cerebrum while avoiding the cerebellum and many of the major fiber tracts ...
The corticobulbar tract is one of the pyramidal tracts, the other being the corticospinal tract. The corticobulbar tract ... The corticobulbar tract directly innervates the nuclei for cranial nerves V, VII, IX, and XII. The corticobulbar tract also ... The corticobulbar tract innervates cranial motor nuclei bilaterally with the exception of the lower facial nuclei (which ... In addition to endings in these motor neurons, fibers of the corticobulbar tract also end in the sensory nuclei of the ...
PPRF is not labeled, but is visible adjacent to the abducens nucleus Frontal eye field Cranial nerves Pyramidal tracts ... In neuroanatomy, corticomesencephalic tract is a descending nerve tract that originates in the frontal eye field (Brodmann area ... It runs rostral to the pyramidal tract in the posterior limb of the internal capsule. Then, it courses posteriorly toward the ... The corticomesencephalic tract originates from the frontal eye field in the caudal part of the middle frontal gyrus and the ...
The pyramidal tract is poorly developed, reflecting the reduction of its limbs. The sperm whale respiratory system has adapted ...
There is neurological damage to the pyramidal tract of the spinal cord. For these older patients, evidence of malnutrition is ... and pyramidal tract myelopathy, with ataxic polyneuropathy". The classification of TAN is still not settled, and researchers ...
"A case of rapid-onset dystonia-parkinsonism accompanied by pyramidal tract impairment". BMC Neurology. 16 (1): 218. doi:10.1186 ...
The pyramids house the pyramidal tracts-the corticospinal and the corticobulbar tracts of the nervous system. At the caudal ... A blood vessel blockage (such as in a stroke) will injure the pyramidal tract, medial lemniscus, and the hypoglossal nucleus. ... The gray matter of this nucleus is covered by a layer of nerve fibers that form the spinal tract of the trigeminal nerve. The ... The word bulbar can refer to the nerves and tracts connected to the medulla, and also by association to those muscles ...
However pons, pyramidal tract and corpus callosum were also involved in these cases. Wichman et al. in 1985 reported three ... identification of white matter tracts. CISS, axial + MPR imaging for evaluation of cerebellar folia, cranial nerves, ventricles ...
M1 finally generates the volley for the pyramidal tract, which then enters consciousness. During the early BP, BP1, the action ...
It was found that the ataxia of this study's participants affected the pyramidal tracts and peripheral nerves. Cerebellar ...
In cerebellar diseases, the movements are irregular and inaccurate; in case of the pyramidal tract lesion the motion may be ...
The motor pathway is the corticospinal (pyramidal) tract and the medial and lateral vestibular tracts. The first stage of the ... Sensorimotor integration is carried out by the cerebellum and by the dorsal column-medial lemniscus tract. ... the dorsal and ventral spinocerebellar tracts. Vision Vestibular apparatus Crucially, the brain can obtain sufficient ...
... affected individuals who exhibit additional pyramidal tract features should a … ... The N355K atlastin 1 mutation is associated with hereditary sensory neuropathy and pyramidal tract features L Leonardis 1 , M ... The N355K atlastin 1 mutation is associated with hereditary sensory neuropathy and pyramidal tract features L Leonardis et al. ... affected individuals who exhibit additional pyramidal tract features should also be screened for mutations in ATL1. ...
... The Amazing Brain: A Sharper Image of the Pyramidal Tract Posted on August 17th, 2021. by Dr. Francis Collins ... In the first second of the video, you see gray, fuzzy images from a diffusion MRI of the pyramidal tract. But, very quickly, a ... What you are viewing is a colorized, 3D reconstruction of a pyramidal tract, which are bundles of nerve fibers that originate ... The top of the pyramidal tract looks pretty good. However, looking lower down, you can see distortions in color and relatively ...
Pyramidal tract. Fibers of the corticospinal tract and corticobulbar tract originate from the sensorimotor cortex around the ... The remaining fibers make up the uncrossed (ie, direct) pyramidal pathway. A large part of direct pyramidal tract fibers ... The human pyramidal tract contains more than 1 million fibers. Most fibers are myelinated and have a small diameter (1-4mm); ... In humans, only 5% of the fibers of the corticospinal tract originate from Betz cells in area 4. The concept of pyramidal ...
... pyramidal tract; Sp5, spinal trigeminal nucleus; 12, hypoglossal nucleus. Bar = 500 μm. ...
... nucleus of the solitary tract; P1, postnatal day 1;pyr, pyramidal tract; tr, solitary tract. Scale bar: C-E, 1 mm; A, 200 μm. ... 1991b) Topographical projections from the cerebral cortex to the nucleus of the solitary tract in the cat. Exp Brain Res 85:75- ... 1998) Oxytocinergic inputs to the nucleus of the solitary tract and dorsal motor nucleus of the vagus in neonatal rats. J Comp ... A small number of infected neurons were observed in the lateral nucleus of the solitary tract, but none were observed in the AP ...
Pyramidal Tracts Actions. * Search in PubMed * Search in MeSH * Add to Search ... while minimizing direct activation of the corticospinal tract of internal capsule, which can elicit sensorimotor side-effects ...
... called tracts) within the brainstem. and spinal cord, especially the pyramidal tract, lateral corticospinal tract, and the ... called tracts) within the spinal cord and the brainstem, which is the part of the brain that connects to the spinal cord. HBSL ...
Pyramidal Tracts/cytology; Rats; Rats, Inbred F344 ... hippocampal CHAT activity and resulted in a loss of pyramidal ...
Synonym: Pyramidal Signs. Synonym: Pyramidal Tract Signs. Abnormal Temper Tantrums. Agenesis of Corpus Callosum. Synonym: ... Abnormal pyramidal sign Abnormal temper tantrums Agenesis of corpus callosum Anorexia Apathy Ataxia Basal ganglia gliosis ...
Pyramidal Tracts/drug effects; Pyramidal Tracts/metabolism; Pyramidal Tracts/pathology; Rats; Rats, Inbred F344; Receptors, ... Colchicine produced a dose-related decrease in the average width and length of the granule cell line; the pyramidal cells in ...
Visualizing and characterizing white matter fiber structure and architecture in the human pyramidal tract using diffusion ... Fiber tract following in the human brain using DT-MRI data. IEICE Trans. Inf. & Syst. E85-D(1):15-21. ... Tract Orientation and Angular Dispersion Deviation Indicator (TOADDI): A framework for single-subject analysis in diffusion ... A model for noise effects on fibre tract trajectories in diffusion tensor imaging: theory and simulations. New Journal of ...
The pyramidal tract has a predictable course through the centrum semiovale: a diffusion-tensor based tractography study. ... Visualization of the pyramidal tract in glioma surgery by integrating diffusion tensor imaging in functional neuronavigation. ... 8. Correlation between pyramidal tract degeneration and widespread white matter involvement in amyotrophic lateral sclerosis: a ... 7. [Role of diffusion tensor imaging in neuronavigation surgery of brain tumors involving pyramidal tracts].. Wu JS; Zhou LF; ...
The pyramidal tract and dentate nuclei had high signal intensity on diffusion-weighted images occurred at a b value of 1000 s/ ... Also noted was involvement of the pyramidal tract and the genu and splenium of the corpus callosum. In one patient (juvenile ... the previous case report presented findings of high signal intensity in the corticospinal tracts on images obtained at a b ...
... indicative of damage to the pyramidal tracts and a permanent upper motor neuron syndrome. (Ecobichon 1996) ... In severe cases, quadriplegia with foot and wrist drop are seen, as well as mild pyramidal signs. (Jokanovic, Stukalov et al. ... The prognosis for functional recovery depends on the degree of pyramidal involvement, with ataxia and paralysis representing a ...
Extrapyramidal Tracts A08.186.854.300 Pyramidal Tracts A08.186.854.348 Gray Matter A08.186.854.443 Spinal Cord Lateral Horn ... Extrapyramidal Tracts A08.612.380.730 Pyramidal Tracts A08.612.435 Internal Capsule A08.612.492 Medial Forebrain Bundle A08.612 ... Spinocerebellar Tracts A08.612.220.735 Spinothalamic Tracts A08.612.220.830 Visceral Afferents A08.612.220.860 Visual Pathways ... Biliary Tract A03.159.183 Bile Ducts A03.159.183.079 Bile Ducts, Extrahepatic A03.159.183.079.300 Common Bile Duct A03.159. ...
... pyramidal tract signs or amyotrophy. Genetic PD disorders or with a strong family history of PD. Presence of dementia (Montreal ...
The N355K atlastin 1 mutation is associated with hereditary sensory neuropathy and pyramidal tract features. Eur J Neurol. 2012 ... Within the long neurons of the corticospinal tracts, these problems can lead to cell death. As a result, the neurons are unable ... corticospinal tracts). These neurons send electrical signals that lead to voluntary muscle movement. In neurons, this protein ...
Grabel D, Ringer TM, Fitzek C, Fitzek S, Kohl M, Kaiser WA, Witte OW, Axer H: Wallerian degeneration of pyramidal tract after ... Longitudinal investigations on the anterograde and retrograde degeneration in the pyramidal tract following pontine infarction ... This minute change in the integrity of the motor tract system might have been due to axonal remodeling imposed by the ... Steiner CM, Barber PA, Smale PR: Functional potential in chronic stroke patients depends on corticospinal tract integrity. ...
During all voluntary movements, Aα and Aγ motor neurons are coactivated by the corticospinal (pyramidal) tract. As a result, ... This is achieved through the complex interaction of the musculoskeletal system with the pyramidal, extrapyramidal, and sensory ...
... pyramidal tracts, basal ganglia, brainstem nuclei, other brain regions and peripheral nerve. In addition, there may be visual ...
Currently, TMS is especially useful in assessing lesions in the pyramidal tract as well as in identifying the location of such ... When areas of pyramidal cells in the cerebral cortex which have dendritic protrusions at the pointed extremity are stimulated, ... because their source is located in the pyramidal cells of the cortex); (2) it is difficult to record activities that are ...
Pyramidal tract. Fibers of the corticospinal tract and corticobulbar tract originate from the sensorimotor cortex around the ... The remaining fibers make up the uncrossed (ie, direct) pyramidal pathway. A large part of direct pyramidal tract fibers ... The human pyramidal tract contains more than 1 million fibers. Most fibers are myelinated and have a small diameter (1-4mm); ... In humans, only 5% of the fibers of the corticospinal tract originate from Betz cells in area 4. The concept of pyramidal ...
... and demonstrated that they possess selective connectivity with intratelecephalic or pyramidal tract neurons. Even when two ... subtypes targeted the same pyramidal cell type, their synaptic targeting proved selective for particular dendritic compartments ...
... pyramidal_tract] 15 ec[external_capsule] 16 ex[extreme_capsule] 17 ilf[inferior_longitudinal_fasciculus] 18 slf[superior_ ...
Pyramidal tract structure (body structure) {72217004 , SNOMED-CT } Parent/Child (Relationship Type) Entire pyramidal tract ( ... Central nervous system tract structure (body structure) {57592002 , SNOMED-CT } Cerebral tracts (body structure) {360567002 , ... Structure of pyramidal decussation (body structure) {44375006 , SNOMED-CT } Structure of ventral corticospinal tract (body ... Structure of lateral corticospinal tract (body structure) {461002 , SNOMED-CT } Structure of pontine portion of corticospinal ...
Tract, Corticobulbar. Tract, Corticospinal. Tract, Pyramidal. Tracts, Corticobulbar. Tracts, Corticospinal. Tracts, Pyramidal. ... Pyramidal Tract Tract, Pyramidal Tracts, Pyramidal Decussation, Pyramidal - Related but not broader or narrower Concept UI. ... Corticobulbar Tracts. Corticospinal Tract. Corticospinal Tracts. Decussation, Pyramidal. Pyramidal Decussation. Pyramidal Tract ... Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts. ...
  • Nerve fibres in the corticospinal tract originate from pyramidal cells in layer V of the cerebral cortex. (wikipedia.org)
  • In humans, only 5% of the fibers of the corticospinal tract originate from Betz cells in area 4. (medscape.com)
  • The pyramidal tracts include both the corticobulbar tract and the corticospinal tract. (wikipedia.org)
  • The corticobulbar tract conducts impulses from the brain to the cranial nerves. (wikipedia.org)
  • Fibers of the corticospinal tract and corticobulbar tract originate from the sensorimotor cortex around the central sulcus. (medscape.com)
  • The axons that cross over move to the outer part of the medulla oblongata and form the lateral corticospinal tract, whereas the fibres that remain form the anterior corticospinal tract. (wikipedia.org)
  • Nerve axons of the lateral corticospinal tract that did not cross over in the medulla oblongata do so at the level of the spinal cord they terminate in. (wikipedia.org)
  • and spinal cord, especially the pyramidal tract, lateral corticospinal tract, and the dorsal column. (medlineplus.gov)
  • The term pyramidal tracts refers to upper motor neurons that originate in the cerebral cortex and terminate in the spinal cord (corticospinal) or brainstem (corticobulbar). (wikipedia.org)
  • citation needed] The nerve axons traveling down the tract are the efferent nerve fibers of the upper motor neurons. (wikipedia.org)
  • It is rich in pyramidal neurons, which provide the anatomical substrates for the motor output function of area 4. (medscape.com)
  • Kraskov A, Baker S, Soteropoulos D, Kirkwood P, Lemon R. The Corticospinal Discrepancy: Where are all the Slow Pyramidal Tract Neurons? . (ncl.ac.uk)
  • Most of the axons of the anterior corticospinal tract will decussate in the spinal cord just before they synapse with lower motor neurons. (physio-pedia.com)
  • The neurons involved (upper motor or corticospinal tract neurons) synapse with neurons in the spinal cord (lower motor neurons). (msdmanuals.com)
  • Disorders of the spinal cord may affect tracts from upper motor neurons, lower motor neurons (anterior horn cells), or both. (msdmanuals.com)
  • The corticospinal tract contains the axons of the pyramidal cells, the largest of which are the Betz cells, located in the cerebral cortex. (wikipedia.org)
  • The cells have their bodies in the cerebral cortex, and the axons form the bulk of the pyramidal tracts. (wikipedia.org)
  • The Corticospinal tract (CST), also known as the pyramidal tract, is a collection of axons that carry movement-related information from the cerebral cortex to the spinal cord. (physio-pedia.com)
  • This is achieved through the complex interaction of the musculoskeletal system with the pyramidal, extrapyramidal, and sensory components of the nervous system. (medscape.com)
  • The primary motor cortex contributes more fibers to the corticospinal tract than any other region. (medscape.com)
  • The human pyramidal tract contains more than 1 million fibers. (medscape.com)
  • The concept of pyramidal pathways with fibers originating only from Betz cells in the primary motor cortex has been invalidated. (medscape.com)
  • Pyramidal fibers converge in the corona radiata, toward the posterior arm of the internal capsule. (medscape.com)
  • We particularly assessed the laminar distribution of iCC cells and fibers, and identified the subtypes of pyramidal cells participating in those projections. (frontiersin.org)
  • At the base of the pyramids , approximately 90% of the fibers in the corticospinal tract decussate, or cross over to the other side of the brainstem, in a bundle of axons called the pyramidal decussation. (physio-pedia.com)
  • The fibers of these two different branches of the corticospinal tract preferentially stimulate activity in different types of muscles. (physio-pedia.com)
  • The corticospinal tract conducts impulses from the brain to the spinal cord. (wikipedia.org)
  • These axons travel down the tracts in the white matter of the spinal cord until they reach the vertebral level of the muscle that they will innervate. (wikipedia.org)
  • In particular, the condition affects nerves in specific regions (called tracts) within the spinal cord and the brainstem, which is the part of the brain that connects to the spinal cord. (medlineplus.gov)
  • Scholars@Duke publication: Isolating two sources of variability of subcortical stimulation to quantify fluctuations of corticospinal tract excitability. (duke.edu)
  • The motor and motivational cortico-subcortical loops and the pyramidal tract are involved in voice and speech disorders in subcortical damage, together with speech apraxia. (bvsalud.org)
  • In addition to the primary lesion, the involvement of fiber tracts contributes to prognosis, and consequently the use of diffusion tensor imaging (DTI) to assess primary and secondary pathways improves the prediction of outcome and of therapeutic effects. (karger.com)
  • Involvement of the pyramidal tract at any level leads to pyramidal signs. (wikipedia.org)
  • The prognosis for functional recovery depends on the degree of pyramidal involvement, with ataxia and paralysis representing a permanent outcome in severe cases. (cdc.gov)
  • [ 2 ] From 1950-1970, several other studies of electrical stimulation of the exposed motor cortex (ie, during neurosurgical procedures) were performed in animals and humans to study the pyramidal pathway and other corticospinal connections. (medscape.com)
  • OBJECTIVE: Investigate the variability previously found with cortical stimulation and handheld transcranial magnetic stimulation (TMS) coils, criticized for its high potential of coil position fluctuations, bypassing the cortex using deep brain electrical stimulation (DBS) of the corticospinal tract with fixed electrodes where both latent variations of the coil position of TMS are eliminated and cortical excitation fluctuations should be absent. (duke.edu)
  • Layer 2/3 (L2/3) pyramidal cells in the frontal cortex send axons mainly to other ipsilateral/contralateral cortical areas. (frontiersin.org)
  • Subpopulations of layer 5 (L5) pyramidal cells that selectively project to the pontine nuclei or to the contralateral cortex [commissural (COM) cells] also target diverse and sometimes overlapping ipsilateral cortical areas. (frontiersin.org)
  • Therefore, to understand the functional operation of the frontal cortex, it is crucial to reveal the formation rules for its corticocortical connections, as well as the relationships between pyramidal cells sending information to the thalamus, basal ganglia, and cerebellum, and those projecting to various cortical areas ( Veinante and Deschênes, 2003 ). (frontiersin.org)
  • In this study, we examine iCC organization in the fontal cortex and reveal the laminar distribution and subtype specificity of pyramidal cells involved in iCC connections between M2 and its target areas. (frontiersin.org)
  • RESULTS: Motor evoked potentials (MEPs) through DBS of the corticospinal tract revealed short-term fluctuations in excitability of the targeted neuron pathway reflecting endogenous input-side variability at similar magnitude as TMS despite bypassing cortical networks. (duke.edu)
  • This is subsequently replaced by spasticity, hypertonicity, hyperreflexia, clonus, and abnormal reflexes, indicative of damage to the pyramidal tracts and a permanent upper motor neuron syndrome. (cdc.gov)
  • Amyotrophic Lateral Sclerosis (ALS) and Other Motor Neuron Diseases (MNDs) Amyotrophic lateral sclerosis and other motor neuron diseases are characterized by steady, relentless, progressive degeneration of corticospinal tracts, anterior horn cells, bulbar motor nuclei. (msdmanuals.com)
  • These tracts contain more than 1 million axons and the majority of the axons are myelinated. (wikipedia.org)
  • The majority of fibres of the corticospinal tract cross over in the medulla oblongata, resulting in muscles being controlled by the opposite side of the brain. (wikipedia.org)
  • The pyramidal tracts are named because they pass through the pyramids of the medulla oblongata. (wikipedia.org)
  • It is made up of a lateral and anterior tract. (wikipedia.org)
  • 10% do not cross over and join the tract, and 10% of fibres travel in the anterior corticospinal tract. (wikipedia.org)
  • this branch of the corticospinal tract is known as the anterior (or ventral) corticospinal tract . (physio-pedia.com)
  • These findings suggest that selective participation in iCC connections by pyramidal cell subtypes lead to directional connectivity between M2 and other cortical areas. (frontiersin.org)
  • After selective damage to the corticospinal tract, patients are usually able to regain the ability to make crude movements (e.g. reaching) after a period of time, but they may be unable to fully recover the ability to make individual finger movements [3] . (physio-pedia.com)
  • These initial findings suggest that the DTI tract-based QSM method has the potential to characterize white matter changes associated with behavioral improvements in CP children who underwent cord blood stem-cell therapy. (nih.gov)
  • In the future, a combination of morphological imaging including DTI of fiber tracts and activation studies during specific tasks might yield the best information on residual function, reserve capacity, and prospects for recovery after ischemic stroke. (karger.com)
  • Pyramidal tract signs were evident late in this case. (go.jp)
  • In severe cases, quadriplegia with foot and wrist drop are seen, as well as mild pyramidal signs. (cdc.gov)
  • A cohort of eight pediatric CP patients (2.6 ± 0.6 years of age) with intact corticospinal tracts (CST) from a randomized, placebo-controlled trial of autologous UCB stem-cell therapy in CP children was included in this study. (nih.gov)
  • An extensor plantar (Babinski) reflex is specific for corticospinal tract dysfunction. (msdmanuals.com)
  • The pyramidal tracts definitively encompass the corticospinal tracts, and many authors also include the corticobulbar tracts. (wikipedia.org)
  • The corticospinal tract is involved in voluntary movement. (wikipedia.org)
  • The myelination of the pyramidal fibres is incomplete at birth and gradually progresses in cranio-caudal direction and thereby progressively gaining functionality. (wikipedia.org)