Basal Ganglia: Large subcortical nuclear masses derived from the telencephalon and located in the basal regions of the cerebral hemispheres.Basal Ganglia Diseases: Diseases of the BASAL GANGLIA including the PUTAMEN; GLOBUS PALLIDUS; claustrum; AMYGDALA; and CAUDATE NUCLEUS. DYSKINESIAS (most notably involuntary movements and alterations of the rate of movement) represent the primary clinical manifestations of these disorders. Common etiologies include CEREBROVASCULAR DISORDERS; NEURODEGENERATIVE DISEASES; and CRANIOCEREBRAL TRAUMA.Ganglia: Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.Retinal Ganglion Cells: Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.Basal Ganglia Hemorrhage: Bleeding within the subcortical regions of cerebral hemispheres (BASAL GANGLIA). It is often associated with HYPERTENSION or ARTERIOVENOUS MALFORMATIONS. Clinical manifestations may include HEADACHE; DYSKINESIAS; and HEMIPARESIS.Ganglia, Spinal: Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.Globus Pallidus: The representation of the phylogenetically oldest part of the corpus striatum called the paleostriatum. It forms the smaller, more medial part of the lentiform nucleus.Ganglia, Sympathetic: Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.Ganglia, Autonomic: Clusters of neurons and their processes in the autonomic nervous system. In the autonomic ganglia, the preganglionic fibers from the central nervous system synapse onto the neurons whose axons are the postganglionic fibers innervating target organs. The ganglia also contain intrinsic neurons and supporting cells and preganglionic fibers passing through to other ganglia.Trigeminal Ganglion: The semilunar-shaped ganglion containing the cells of origin of most of the sensory fibers of the trigeminal nerve. It is situated within the dural cleft on the cerebral surface of the petrous portion of the temporal bone and gives off the ophthalmic, maxillary, and part of the mandibular nerves.Basal Ganglia Cerebrovascular Disease: A pathological condition caused by impaired blood flow in the basal regions of cerebral hemispheres (BASAL GANGLIA), such as INFARCTION; HEMORRHAGE; or ISCHEMIA in vessels of this brain region including the lateral lenticulostriate arteries. Primary clinical manifestations include involuntary movements (DYSKINESIAS) and muscle weakness (HEMIPARESIS).Ganglia, Parasympathetic: Ganglia of the parasympathetic nervous system, including the ciliary, pterygopalatine, submandibular, and otic ganglia in the cranial region and intrinsic (terminal) ganglia associated with target organs in the thorax and abdomen.Ganglia, Sensory: Clusters of neurons in the somatic peripheral nervous system which contain the cell bodies of sensory nerve axons. Sensory ganglia may also have intrinsic interneurons and non-neuronal supporting cells.Putamen: The largest and most lateral of the BASAL GANGLIA lying between the lateral medullary lamina of the GLOBUS PALLIDUS and the EXTERNAL CAPSULE. It is part of the neostriatum and forms part of the LENTIFORM NUCLEUS along with the GLOBUS PALLIDUS.Subthalamic Nucleus: Lens-shaped structure on the inner aspect of the INTERNAL CAPSULE. The SUBTHALAMIC NUCLEUS and pathways traversing this region are concerned with the integration of somatic motor function.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Stellate Ganglion: A paravertebral sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia.Magnetic Resonance Imaging: 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: 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.Corpus Striatum: Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.Parkinson Disease: A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)Substantia Nigra: The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Caudate Nucleus: Elongated gray mass of the neostriatum located adjacent to the lateral ventricle of the brain.Spiral Ganglion: The sensory ganglion of the COCHLEAR NERVE. The cells of the spiral ganglion send fibers peripherally to the cochlear hair cells and centrally to the COCHLEAR NUCLEI of the BRAIN STEM.Nodose Ganglion: The inferior (caudal) ganglion of the vagus (10th cranial) nerve. The unipolar nodose ganglion cells are sensory cells with central projections to the medulla and peripheral processes traveling in various branches of the vagus nerve.Dystonia: An attitude or posture due to the co-contraction of agonists and antagonist muscles in one region of the body. It most often affects the large axial muscles of the trunk and limb girdles. Conditions which feature persistent or recurrent episodes of dystonia as a primary manifestation of disease are referred to as DYSTONIC DISORDERS. (Adams et al., Principles of Neurology, 6th ed, p77)Chorea: Involuntary, forcible, rapid, jerky movements that may be subtle or become confluent, markedly altering normal patterns of movement. Hypotonia and pendular reflexes are often associated. Conditions which feature recurrent or persistent episodes of chorea as a primary manifestation of disease are referred to as CHOREATIC DISORDERS. Chorea is also a frequent manifestation of BASAL GANGLIA DISEASES.Ganglia, Invertebrate: Clusters of neuronal cell bodies in invertebrates. Invertebrate ganglia may also contain neuronal processes and non-neuronal supporting cells. Many invertebrate ganglia are favorable subjects for research because they have small numbers of functional neuronal types which can be identified from one animal to another.Superior Cervical Ganglion: The largest and uppermost of the paravertebral sympathetic ganglia.Movement Disorders: Syndromes which feature DYSKINESIAS as a cardinal manifestation of the disease process. Included in this category are degenerative, hereditary, post-infectious, medication-induced, post-inflammatory, and post-traumatic conditions.Parkinsonian Disorders: A group of disorders which feature impaired motor control characterized by bradykinesia, MUSCLE RIGIDITY; TREMOR; and postural instability. Parkinsonian diseases are generally divided into primary parkinsonism (see PARKINSON DISEASE), secondary parkinsonism (see PARKINSON DISEASE, SECONDARY) and inherited forms. These conditions are associated with dysfunction of dopaminergic or closely related motor integration neuronal pathways in the BASAL GANGLIA.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Entopeduncular Nucleus: A portion of the nucleus of ansa lenticularis located medial to the posterior limb of the internal capsule, along the course of the ansa lenticularis and the inferior thalamic peduncle or as a separate nucleus within the internal capsule adjacent to the medial GLOBUS PALLIDUS (NeuroNames, http://rprcsgi.rprc. washington.edu/neuronames/ (September 28, 1998)). In non-primates, the entopeduncular nucleus is analogous to both the medial globus pallidus and the entopeduncular nucleus of human.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Parkinson Disease, Secondary: Conditions which feature clinical manifestations resembling primary Parkinson disease that are caused by a known or suspected condition. Examples include parkinsonism caused by vascular injury, drugs, trauma, toxin exposure, neoplasms, infections and degenerative or hereditary conditions. Clinical features may include bradykinesia, rigidity, parkinsonian gait, and masked facies. In general, tremor is less prominent in secondary parkinsonism than in the primary form. (From Joynt, Clinical Neurology, 1998, Ch38, pp39-42)Cebus: A genus of the family CEBIDAE, subfamily CEBINAE, consisting of four species which are divided into two groups, the tufted and untufted. C. apella has tufts of hair over the eyes and sides of the head. The remaining species are without tufts - C. capucinus, C. nigrivultatus, and C. albifrons. Cebus inhabits the forests of Central and South America.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Levodopa: The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Neostriatum: The phylogenetically newer part of the CORPUS STRIATUM consisting of the CAUDATE NUCLEUS and PUTAMEN. It is often called simply the striatum.Dystonic Disorders: Acquired and inherited conditions that feature DYSTONIA as a primary manifestation of disease. These disorders are generally divided into generalized dystonias (e.g., dystonia musculorum deformans) and focal dystonias (e.g., writer's cramp). They are also classified by patterns of inheritance and by age of onset.Deep Brain Stimulation: Therapy for MOVEMENT DISORDERS, especially PARKINSON DISEASE, that applies electricity via stereotactic implantation of ELECTRODES in specific areas of the BRAIN such as the THALAMUS. The electrodes are attached to a neurostimulator placed subcutaneously.Hypokinesia: Slow or diminished movement of body musculature. It may be associated with BASAL GANGLIA DISEASES; MENTAL DISORDERS; prolonged inactivity due to illness; and other conditions.Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Oxidopamine: A neurotransmitter analogue that depletes noradrenergic stores in nerve endings and induces a reduction of dopamine levels in the brain. Its mechanism of action is related to the production of cytolytic free-radicals.Manganese Poisoning: Manganese poisoning is associated with chronic inhalation of manganese particles by individuals who work with manganese ore. Clinical features include CONFUSION; HALLUCINATIONS; and an extrapyramidal syndrome (PARKINSON DISEASE, SECONDARY) that includes rigidity; DYSTONIA; retropulsion; and TREMOR. (Adams, Principles of Neurology, 6th ed, p1213)Finches: Common name for small PASSERIFORMES in the family Fringillidae. They have a short stout bill (BEAK) adapted for crushing SEEDS. Some species of Old World finches are called CANARIES.Geniculate Ganglion: The sensory ganglion of the facial (7th cranial) nerve. The geniculate ganglion cells send central processes to the brain stem and peripheral processes to the taste buds in the anterior tongue, the soft palate, and the skin of the external auditory meatus and the mastoid process.Thalamic Diseases: Disorders of the centrally located thalamus, which integrates a wide range of cortical and subcortical information. Manifestations include sensory loss, MOVEMENT DISORDERS; ATAXIA, pain syndromes, visual disorders, a variety of neuropsychological conditions, and COMA. Relatively common etiologies include CEREBROVASCULAR DISORDERS; CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; BRAIN HYPOXIA; INTRACRANIAL HEMORRHAGES; and infectious processes.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Cerebellum: The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.Axons: Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.Dominance, Cerebral: Dominance of one cerebral hemisphere over the other in cerebral functions.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Vocalization, Animal: Sounds used in animal communication.Dyskinesias: Abnormal involuntary movements which primarily affect the extremities, trunk, or jaw that occur as a manifestation of an underlying disease process. Conditions which feature recurrent or persistent episodes of dyskinesia as a primary manifestation of disease may be referred to as dyskinesia syndromes (see MOVEMENT DISORDERS). Dyskinesias are also a relatively common manifestation of BASAL GANGLIA DISEASES.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Receptors, Dopamine D2: A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLYL CYCLASES.Brain Diseases: Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.Thalamic Nuclei: Several groups of nuclei in the thalamus that serve as the major relay centers for sensory impulses in the brain.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Dopamine Agonists: Drugs that bind to and activate dopamine receptors.Reaction Time: The time from the onset of a stimulus until a response is observed.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Antiparkinson Agents: Agents used in the treatment of Parkinson's disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists.Image Processing, Computer-Assisted: 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.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Tourette Syndrome: A neuropsychological disorder related to alterations in DOPAMINE metabolism and neurotransmission involving frontal-subcortical neuronal circuits. Both multiple motor and one or more vocal tics need to be present with TICS occurring many times a day, nearly daily, over a period of more than one year. The onset is before age 18 and the disturbance is not due to direct physiological effects of a substance or a another medical condition. The disturbance causes marked distress or significant impairment in social, occupational, or other important areas of functioning. (From DSM-IV, 1994; Neurol Clin 1997 May;15(2):357-79)Dyskinesia, Drug-Induced: Abnormal movements, including HYPERKINESIS; HYPOKINESIA; TREMOR; and DYSTONIA, associated with the use of certain medications or drugs. Muscles of the face, trunk, neck, and extremities are most commonly affected. Tardive dyskinesia refers to abnormal hyperkinetic movements of the muscles of the face, tongue, and neck associated with the use of neuroleptic agents (see ANTIPSYCHOTIC AGENTS). (Adams et al., Principles of Neurology, 6th ed, p1199)Macaca fascicularis: A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.Stereotyped Behavior: Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.Muscle Rigidity: Continuous involuntary sustained muscle contraction which is often a manifestation of BASAL GANGLIA DISEASES. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from MUSCLE SPASTICITY. (From Adams et al., Principles of Neurology, 6th ed, p73)Receptors, Dopamine D1: A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D1-class receptor genes lack INTRONS, and the receptors stimulate ADENYLYL CYCLASES.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Motor Cortex: Area of the FRONTAL LOBE concerned with primary motor control located in the dorsal PRECENTRAL GYRUS immediately anterior to the central sulcus. It is comprised of three areas: the primary motor cortex located on the anterior paracentral lobule on the medial surface of the brain; the premotor cortex located anterior to the primary motor cortex; and the supplementary motor area located on the midline surface of the hemisphere anterior to the primary motor cortex.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Frontal Lobe: The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.Optic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Songbirds: PASSERIFORMES of the suborder, Oscines, in which the flexor tendons of the toes are separate, and the lower syrinx has 4 to 9 pairs of tensor muscles inserted at both ends of the tracheal half rings. They include many commonly recognized birds such as CROWS; FINCHES; robins; SPARROWS; and SWALLOWS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cerebral Hemorrhage: Bleeding into one or both CEREBRAL HEMISPHERES including the BASAL GANGLIA and the CEREBRAL CORTEX. It is often associated with HYPERTENSION and CRANIOCEREBRAL TRAUMA.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Behavior, Animal: The observable response an animal makes to any situation.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Huntington Disease: A familial disorder inherited as an autosomal dominant trait and characterized by the onset of progressive CHOREA and DEMENTIA in the fourth or fifth decade of life. Common initial manifestations include paranoia; poor impulse control; DEPRESSION; HALLUCINATIONS; and DELUSIONS. Eventually intellectual impairment; loss of fine motor control; ATHETOSIS; and diffuse chorea involving axial and limb musculature develops, leading to a vegetative state within 10-15 years of disease onset. The juvenile variant has a more fulminant course including SEIZURES; ATAXIA; dementia; and chorea. (From Adams et al., Principles of Neurology, 6th ed, pp1060-4)Nerve Tissue ProteinsAutonomic Fibers, Preganglionic: NERVE FIBERS which project from the central nervous system to AUTONOMIC GANGLIA. In the sympathetic division most preganglionic fibers originate with neurons in the intermediolateral column of the SPINAL CORD, exit via ventral roots from upper thoracic through lower lumbar segments, and project to the paravertebral ganglia; there they either terminate in SYNAPSES or continue through the SPLANCHNIC NERVES to the prevertebral ganglia. In the parasympathetic division the fibers originate in neurons of the BRAIN STEM and sacral spinal cord. In both divisions the principal transmitter is ACETYLCHOLINE but peptide cotransmitters may also be released.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Tyrosine 3-Monooxygenase: An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Receptors, Dopamine: Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Axonal Transport: The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)Denervation: The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Brain Diseases, Metabolic: Acquired or inborn metabolic diseases that produce brain dysfunction or damage. These include primary (i.e., disorders intrinsic to the brain) and secondary (i.e., extracranial) metabolic conditions that adversely affect cerebral function.Atrophy: Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.Tomography, Emission-Computed: Tomography using radioactive emissions from injected RADIONUCLIDES and computer ALGORITHMS to reconstruct an image.Efferent Pathways: Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.Tomography, Emission-Computed, Single-Photon: A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.Stereotaxic Techniques: Techniques used mostly during brain surgery which use a system of three-dimensional coordinates to locate the site to be operated on.Beta Rhythm: Brain waves with frequency between 15-30 Hz seen on EEG during wakefulness and mental activity.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Supranuclear Palsy, Progressive: A degenerative disease of the central nervous system characterized by balance difficulties; OCULAR MOTILITY DISORDERS (supranuclear ophthalmoplegia); DYSARTHRIA; swallowing difficulties; and axial DYSTONIA. Onset is usually in the fifth decade and disease progression occurs over several years. Pathologic findings include neurofibrillary degeneration and neuronal loss in the dorsal MESENCEPHALON; SUBTHALAMIC NUCLEUS; RED NUCLEUS; pallidum; dentate nucleus; and vestibular nuclei. (From Adams et al., Principles of Neurology, 6th ed, pp1076-7)Dopamine Agents: Any drugs that are used for their effects on dopamine receptors, on the life cycle of dopamine, or on the survival of dopaminergic neurons.Nerve Degeneration: Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.Visual Pathways: Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.MPTP Poisoning: A condition caused by the neurotoxin MPTP which causes selective destruction of nigrostriatal dopaminergic neurons. Clinical features include irreversible parkinsonian signs including rigidity and bradykinesia (PARKINSON DISEASE, SECONDARY). MPTP toxicity is also used as an animal model for the study of PARKINSON DISEASE. (Adams et al., Principles of Neurology, 6th ed, p1072; Neurology 1986 Feb;36(2):250-8)Organotechnetium Compounds: Organic compounds that contain technetium as an integral part of the molecule. These compounds are often used as radionuclide imaging agents.Interneurons: Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.Electrodes, Implanted: Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine: A dopaminergic neurotoxic compound which produces irreversible clinical, chemical, and pathological alterations that mimic those found in Parkinson disease.Propionic Acidemia: Autosomal recessive metabolic disorder caused by mutations in PROPIONYL-COA CARBOXYLASE genes that result in dysfunction of branch chain amino acids and of the metabolism of certain fatty acids. Neonatal clinical onset is characterized by severe metabolic acidemia accompanied by hyperammonemia, HYPERGLYCEMIA, lethargy, vomiting, HYPOTONIA; and HEPATOMEGALY. Survivors of the neonatal onset propionic acidemia often show developmental retardation, and intolerance to dietary proteins. Late-onset form of the disease shows mild mental and/or developmental retardation, sometimes without metabolic acidemia.Tremor: Cyclical movement of a body part that can represent either a physiologic process or a manifestation of disease. Intention or action tremor, a common manifestation of CEREBELLAR DISEASES, is aggravated by movement. In contrast, resting tremor is maximal when there is no attempt at voluntary movement, and occurs as a relatively frequent manifestation of PARKINSON DISEASE.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Hypoparathyroidism: A condition caused by a deficiency of PARATHYROID HORMONE (or PTH). It is characterized by HYPOCALCEMIA and hyperphosphatemia. Hypocalcemia leads to TETANY. The acquired form is due to removal or injuries to the PARATHYROID GLANDS. The congenital form is due to mutations of genes, such as TBX1; (see DIGEORGE SYNDROME); CASR encoding CALCIUM-SENSING RECEPTOR; or PTH encoding parathyroid hormone.Technetium Tc 99m Exametazime: A gamma-emitting RADIONUCLIDE IMAGING agent used in the evaluation of regional cerebral blood flow and in non-invasive dynamic biodistribution studies and MYOCARDIAL PERFUSION IMAGING. It has also been used to label leukocytes in the investigation of INFLAMMATORY BOWEL DISEASES.Biological Clocks: The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Neurologic Examination: Assessment of sensory and motor responses and reflexes that is used to determine impairment of the nervous system.Reward: An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.Amacrine Cells: INTERNEURONS of the vertebrate RETINA. They integrate, modulate, and interpose a temporal domain in the visual message presented to the RETINAL GANGLION CELLS, with which they synapse in the inner plexiform layer.Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.Dopamine Antagonists: Drugs that bind to but do not activate DOPAMINE RECEPTORS, thereby blocking the actions of dopamine or exogenous agonists. Many drugs used in the treatment of psychotic disorders (ANTIPSYCHOTIC AGENTS) are dopamine antagonists, although their therapeutic effects may be due to long-term adjustments of the brain rather than to the acute effects of blocking dopamine receptors. Dopamine antagonists have been used for several other clinical purposes including as ANTIEMETICS, in the treatment of Tourette syndrome, and for hiccup. Dopamine receptor blockade is associated with NEUROLEPTIC MALIGNANT SYNDROME.Superior Colliculi: The anterior pair of the quadrigeminal bodies which coordinate the general behavioral orienting responses to visual stimuli, such as whole-body turning, and reaching.Sensory Receptor Cells: Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.Automatism: Automatic, mechanical, and apparently undirected behavior which is outside of conscious control.Oximes: Compounds that contain the radical R2C=N.OH derived from condensation of ALDEHYDES or KETONES with HYDROXYLAMINE. Members of this group are CHOLINESTERASE REACTIVATORS.Intracranial Hemorrhage, Hypertensive: Bleeding within the SKULL that is caused by systemic HYPERTENSION, usually in association with INTRACRANIAL ARTERIOSCLEROSIS. Hypertensive hemorrhages are most frequent in the BASAL GANGLIA; CEREBELLUM; PONS; and THALAMUS; but may also involve the CEREBRAL CORTEX, subcortical white matter, and other brain structures.Motor Skills: Performance of complex motor acts.Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate: The lectin wheatgerm agglutinin conjugated to the enzyme HORSERADISH PEROXIDASE. It is widely used for tracing neural pathways.Calcinosis: Pathologic deposition of calcium salts in tissues.Optic Nerve Injuries: Injuries to the optic nerve induced by a trauma to the face or head. These may occur with closed or penetrating injuries. Relatively minor compression of the superior aspect of orbit may also result in trauma to the optic nerve. Clinical manifestations may include visual loss, PAPILLEDEMA, and an afferent pupillary defect.Brain Stem: The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.Animals, Newborn: Refers to animals in the period of time just after birth.Telencephalon: The anterior subdivision of the embryonic PROSENCEPHALON or the corresponding part of the adult prosencephalon that includes the cerebrum and associated structures.Substance P: An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.Limbic System: A set of forebrain structures common to all mammals that is defined functionally and anatomically. It is implicated in the higher integration of visceral, olfactory, and somatic information as well as homeostatic responses including fundamental survival behaviors (feeding, mating, emotion). For most authors, it includes the AMYGDALA; EPITHALAMUS; GYRUS CINGULI; hippocampal formation (see HIPPOCAMPUS); HYPOTHALAMUS; PARAHIPPOCAMPAL GYRUS; SEPTAL NUCLEI; anterior nuclear group of thalamus, and portions of the basal ganglia. (Parent, Carpenter's Human Neuroanatomy, 9th ed, p744; NeuroNames, http://rprcsgi.rprc.washington.edu/neuronames/index.html (September 2, 1998)).Microelectrodes: Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)Cerebral Infarction: 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).Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Apomorphine: A derivative of morphine that is a dopamine D2 agonist. It is a powerful emetic and has been used for that effect in acute poisoning. It has also been used in the diagnosis and treatment of parkinsonism, but its adverse effects limit its use.Torticollis: A symptom, not a disease, of a twisted neck. In most instances, the head is tipped toward one side and the chin rotated toward the other. The involuntary muscle contractions in the neck region of patients with torticollis can be due to congenital defects, trauma, inflammation, tumors, and neurological or other factors.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Dopamine and cAMP-Regulated Phosphoprotein 32: A phosphoprotein that was initially identified as a major target of DOPAMINE activated ADENYLYL CYCLASE in the CORPUS STRIATUM. It regulates the activities of PROTEIN PHOSPHATASE-1 and PROTEIN KINASE A, and it is a key mediator of the biochemical, electrophysiological, transcriptional, and behavioral effects of DOPAMINE.Choline O-Acetyltransferase: An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.Diffusion Magnetic Resonance Imaging: 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.Neuroacanthocytosis: An inherited autosomal disorder that is characterized by neurodegeneration; orofacial and buccal DYSKINESIAS; CHOREA; and thorny-looking red cells (ACANTHOCYTES). This disorder is due to mutations of chorein which is important in protein trafficking and is encoded by Vps13a on chromosome 9q21.Dendrites: Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.Mice, Inbred C57BLHabenula: A small protuberance at the dorsal, posterior corner of the wall of the THIRD VENTRICLE, adjacent to the dorsal THALAMUS and PINEAL BODY. It contains the habenular nuclei and is a major part of the epithalamus.Intralaminar Thalamic Nuclei: Cell groups within the internal medullary lamina of the THALAMUS. They include a rostral division comprising the paracentral, central lateral, central dorsal, and central medial nuclei, and a caudal division composed of the centromedian and parafascicular nuclei.Myoclonus: Involuntary shock-like contractions, irregular in rhythm and amplitude, followed by relaxation, of a muscle or a group of muscles. This condition may be a feature of some CENTRAL NERVOUS SYSTEM DISEASES; (e.g., EPILEPSY, MYOCLONIC). Nocturnal myoclonus is the principal feature of the NOCTURNAL MYOCLONUS SYNDROME. (From Adams et al., Principles of Neurology, 6th ed, pp102-3).Wernicke Encephalopathy: An acute neurological disorder characterized by the triad of ophthalmoplegia, ataxia, and disturbances of mental activity or consciousness. Eye movement abnormalities include nystagmus, external rectus palsies, and reduced conjugate gaze. THIAMINE DEFICIENCY and chronic ALCOHOLISM are associated conditions. Pathologic features include periventricular petechial hemorrhages and neuropil breakdown in the diencephalon and brainstem. Chronic thiamine deficiency may lead to KORSAKOFF SYNDROME. (Adams et al., Principles of Neurology, 6th ed, pp1139-42; Davis & Robertson, Textbook of Neuropathology, 2nd ed, pp452-3)Nerve Fibers: Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.Intuition: Knowing or understanding without conscious use of reasoning. (Thesaurus of ERIC Descriptors, 1994)Autoimmune Diseases of the Nervous System: Disorders caused by cellular or humoral immune responses primarily directed towards nervous system autoantigens. The immune response may be directed towards specific tissue components (e.g., myelin) and may be limited to the central nervous system (e.g., MULTIPLE SCLEROSIS) or the peripheral nervous system (e.g., GUILLAIN-BARRE SYNDROME).Enkephalins: One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.AIDS Dementia Complex: A neurologic condition associated with the ACQUIRED IMMUNODEFICIENCY SYNDROME and characterized by impaired concentration and memory, slowness of hand movements, ATAXIA, incontinence, apathy, and gait difficulties associated with HIV-1 viral infection of the central nervous system. Pathologic examination of the brain reveals white matter rarefaction, perivascular infiltrates of lymphocytes, foamy macrophages, and multinucleated giant cells. (From Adams et al., Principles of Neurology, 6th ed, pp760-1; N Engl J Med, 1995 Apr 6;332(14):934-40)Axotomy: Transection or severing of an axon. This type of denervation is used often in experimental studies on neuronal physiology and neuronal death or survival, toward an understanding of nervous system disease.Adrenergic Agents: Drugs that act on adrenergic receptors or affect the life cycle of adrenergic transmitters. Included here are adrenergic agonists and antagonists and agents that affect the synthesis, storage, uptake, metabolism, or release of adrenergic transmitters.Nerve Growth Factors: Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Quinpirole: A dopamine D2/D3 receptor agonist.Brain Chemistry: Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.Hypogastric Plexus: A complex network of nerve fibers in the pelvic region. The hypogastric plexus distributes sympathetic fibers from the lumbar paravertebral ganglia and the aortic plexus, parasympathetic fibers from the pelvic nerve, and visceral afferents. The bilateral pelvic plexus is in its lateral extent.Brain Damage, Chronic: A condition characterized by long-standing brain dysfunction or damage, usually of three months duration or longer. Potential etiologies include BRAIN INFARCTION; certain NEURODEGENERATIVE DISORDERS; CRANIOCEREBRAL TRAUMA; ANOXIA, BRAIN; ENCEPHALITIS; certain NEUROTOXICITY SYNDROMES; metabolic disorders (see BRAIN DISEASES, METABOLIC); and other conditions.Macaca: 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.Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Serial Learning: Learning to make a series of responses in exact order.Cerebellar Ataxia: Incoordination of voluntary movements that occur as a manifestation of CEREBELLAR DISEASES. Characteristic features include a tendency for limb movements to overshoot or undershoot a target (dysmetria), a tremor that occurs during attempted movements (intention TREMOR), impaired force and rhythm of diadochokinesis (rapidly alternating movements), and GAIT ATAXIA. (From Adams et al., Principles of Neurology, 6th ed, p90)Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Parvalbumins: Low molecular weight, calcium binding muscle proteins. Their physiological function is possibly related to the contractile process.Cortical Synchronization: EEG phase synchronization of the cortical brain region (CEREBRAL CORTEX).Dihydroxyphenylalanine: A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.Neurodegenerative Diseases: Hereditary and sporadic conditions which are characterized by progressive nervous system dysfunction. These disorders are often associated with atrophy of the affected central or peripheral nervous system structures.Multiple System Atrophy: A syndrome complex composed of three conditions which represent clinical variants of the same disease process: STRIATONIGRAL DEGENERATION; SHY-DRAGER SYNDROME; and the sporadic form of OLIVOPONTOCEREBELLAR ATROPHIES. Clinical features include autonomic, cerebellar, and basal ganglia dysfunction. Pathologic examination reveals atrophy of the basal ganglia, cerebellum, pons, and medulla, with prominent loss of autonomic neurons in the brain stem and spinal cord. (From Adams et al., Principles of Neurology, 6th ed, p1076; Baillieres Clin Neurol 1997 Apr;6(1):187-204; Med Clin North Am 1999 Mar;83(2):381-92)Periodicity: The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).Muscimol: A neurotoxic isoxazole isolated from species of AMANITA. It is obtained by decarboxylation of IBOTENIC ACID. Muscimol is a potent agonist of GABA-A RECEPTORS and is used mainly as an experimental tool in animal and tissue studies.Neurotransmitter Agents: Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.Autoradiography: The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)Parkinson Disease, Postencephalitic: Parkinsonism following encephalitis, historically seen as a sequella of encephalitis lethargica (Von Economo Encephalitis). The early age of onset, the rapid progression of symptoms followed by stabilization, and the presence of a variety of other neurological disorders (e.g., sociopathic behavior; TICS; MUSCLE SPASMS; oculogyric crises; hyperphagia; and bizarre movements) distinguish this condition from primary PARKINSON DISEASE. Pathologic features include neuronal loss and gliosis concentrated in the MESENCEPHALON; SUBTHALAMUS; and HYPOTHALAMUS. (From Adams et al., Principles of Neurology, 6th ed, p754)Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Akinetic Mutism: A syndrome characterized by a silent and inert state without voluntary motor activity despite preserved sensorimotor pathways and vigilance. Bilateral FRONTAL LOBE dysfunction involving the anterior cingulate gyrus and related brain injuries are associated with this condition. This may result in impaired abilities to communicate and initiate motor activities. (From Adams et al., Principles of Neurology, 6th ed, p348; Fortschr Neurol Psychiatr 1995 Feb;63(2):59-67)Autonomic Fibers, Postganglionic: Nerve fibers which project from cell bodies of AUTONOMIC GANGLIA to SYNAPSES on target organs.Neuroimaging: Non-invasive methods of visualizing the CENTRAL NERVOUS SYSTEM, especially the brain, by various imaging modalities.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Neuroglia: The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.

Concordant induction of cyclin E and p21cip1 in differentiated keratinocytes by the human papillomavirus E7 protein inhibits cellular and viral DNA synthesis. (1/1612)

Productive infections by human papillomaviruses (HPVs) occur only in differentiated keratinocytes in squamous epithelia in which the HPV E7 protein reactivates the host DNA replication machinery to support viral DNA replication. In a fraction of the differentiated keratinocytes, E7 also posttranscriptionally induces p21Cip1, which is distributed in a mutually exclusive manner with unscheduled cellular DNA synthesis. In this study, double immunofluorescence labeling unexpectedly revealed that E7 caused a concordant accumulation of both cyclin E and p21Cip1 to high levels in patient papillomas and in organotypic cultures of primary human keratinocytes. The induction of cyclin E is mutually exclusive with unscheduled cellular DNA synthesis or abundant viral DNA. These novel virus-host interactions in differentiated keratinocytes are in contrast to previous observations made in submerged proliferating cultures, in which HPV E7 induces cyclin E and overcomes p21Cip1 inhibition of S-phase entry. We propose that an appropriately timed induction of cyclin E/cyclin-dependent kinase 2 by HPV E7 in postmitotic cells enables S-phase reentry and HPV DNA amplification, whereas prematurely induced cyclin E stabilizes p21Cip1 protein, which then inhibits cyclin E/cyclin-dependent kinase 2. Consequently, cyclin E and p21Cip1 both fail to turn over, and DNA synthesis does not occur.  (+info)

Developmental regulation of expression of the D3 dopamine receptor in rat nucleus accumbens and islands of Calleja. (2/1612)

The dopamine D3 receptor (D3R) belongs to the D2 subfamily and is expressed in the rat brain in targets of the mesolimbic dopaminergic system. Little is known about its normal development and control by dopaminergic innervation. We studied developmental expression of D3R in the rat nucleus accumbens (NAC) and islands of Calleja (ISC). At postnatal day (P) 7, D3 binding sites and mRNA were low in both areas. By P14, D3R and mRNA concentrations were close to adult levels in the ISC, whereas, in the NAC, binding increased until 3 months after birth. Cellular concentrations of D3 mRNA in the ISC increased with age in conjunction with a decrease in the number of D3 positive cells. In the NAC, the number of positive cells increased, whereas cellular levels of expression remained unchanged. Neonatal 6-hydroxydopamine lesion caused age-dependent changes in D3R expression. D3 binding sites did not change at P7 or P14, but there was a reduction in the number of D3 mRNA positive neurons accompanied by an increase in cellular levels of D3 mRNA at P14, suggesting that changes occurred in a subset of neurons. Up-regulation of D3 binding sites in NAC and ISC occurred 1 month after the lesion (P35) concomitant with a decrease in cellular levels of D3 mRNA and the number of D3 mRNA positive cells. At 3 months (P90) after the lesion, an increase in D3 mRNA occurred with no change in D3 binding sites. D3R shows region-specific dynamics in receptor/mRNA expression during development and is sensitive to loss of dopamine in early postnatal development.  (+info)

Bilateral basal ganglial necrosis after allogeneic bone marrow transplantation in a child with Kostmann syndrome. (3/1612)

A 6-year-old girl underwent allogeneic BMT from a matched sibling donor for the treatment of Kostmann syndrome. She suddenly became drowsy on day 30 after BMT, and lost consciousness 2 days later. Cranial CT scan showed symmetrical lesions suggesting bilateral necrosis in the basal ganglia. Clinical and laboratory investigations failed to reveal any evidence of neurometabolic disease.  (+info)

5-HT modulation of dopamine release in basal ganglia in psilocybin-induced psychosis in man--a PET study with [11C]raclopride. (4/1612)

The modulating effects of serotonin on dopamine neurotransmission are not well understood, particularly in acute psychotic states. Positron emission tomography was used to examine the effect of psilocybin on the in vivo binding of [11C]raclopride to D2-dopamine receptors in the striatum in healthy volunteers after placebo and a psychotomimetic dose of psilocybin (n = 7). Psilocybin is a potent indoleamine hallucinogen and a mixed 5-HT2A and 5-HT1A receptor agonist. Psilocybin administration (0.25 mg/kg p.o.) produced changes in mood, disturbances in thinking, illusions, elementary and complex visual hallucinations and impaired ego-functioning. Psilocybin significantly decreased [11C]raclopride receptor binding potential (BP) bilaterally in the caudate nucleus (19%) and putamen (20%) consistent with an increase in endogenous dopamine. Changes in [11C]raclopride BP in the ventral striatum correlated with depersonalization associated with euphoria. Together with previous reports of 5-HT receptor involvement in striatal dopamine release, it is concluded that stimulation of both 5-HT2A and 5-HT1A receptors may be important for the modulation of striatal dopamine release in acute psychoses. The present results indirectly support the hypothesis of a serotonin-dopamine dysbalance in schizophrenia and suggest that psilocybin is a valuable tool in the analysis of serotonin-dopamine interactions in acute psychotic states.  (+info)

Impairment of EEG desynchronisation before and during movement and its relation to bradykinesia in Parkinson's disease. (5/1612)

OBJECTIVE: It has been suggested that the basal ganglia act to release cortical elements from idling (alpha) rhythms so that they may become coherent in the gamma range, thereby binding together those distributed activities necessary for the effective selection and execution of a motor act. This hypothesis was tested in 10 patients with idiopathic Parkinson's disease. METHODS: Surface EEG was recorded during self paced squeezing of the hand and elbow flexion performed separately, simultaneously, or sequentially. Recordings were made after overnight withdrawal of medication and, again, 1 hour after levodopa. The medication related improvement in EEG desynchronisation (in the 7.5-12.5 Hz band) over the 1 second before movement and during movement were separately correlated with the improvement in movement time for each electrode site. Correlation coefficients (r) > 0.632 were considered significant (p<0.05). RESULTS: Improvement in premovement desynchronisation correlated with reduction in bradykinesia over the contralateral sensorimotor cortex and supplementary motor area in flexion and squeeze, respectively. However, when both movements were combined either simultaneously or sequentially, this correlation shifted anteriorly, to areas overlying prefrontal cortex. Improvement in EEG desynchronisation during movement only correlated with reduction in bradykinesia in two tasks. Correlation was seen over the supplementary motor area during flexion, and central prefrontal and ipsilateral premotor areas during simultaneous flex and squeeze. CONCLUSIONS: The results are consistent with the idea that the basal ganglia liberate frontal cortex from idling rhythms, and that this effect is focused and specific in so far as it changes with the demands of the task. In particular, the effective selection and execution of more complex tasks is associated with changes over the prefrontal cortex.  (+info)

Variation in echogenicity of the basal ganglia: anisotropic effect. (6/1612)

We observed that the fetal brain demonstrates relatively increased echogenicity of the basal ganglia compared with the thalami and cortical brain parenchyma, which we did not observe on neonatal sonograms. We hypothesized that the difference in relative echogenicity was due to differences in imaging techniques and anisotropic effects for prenatal and postnatal brain images. In 18 consecutive neonates, we obtained coronal images of the basal ganglia and thalami through the anterior fontanelle and axial images through the anterolateral fontanelle with both 5 and 7.5 MHz transducers. Two observers determined whether increased echogenicity or conspicuity of the basal ganglia was present, comparing the axial and coronal planes. We observed relatively increased echogenicity of the basal ganglia in the axial plane in 11 of the 16 examinations in this series. Of these 11, the increased echogenicity effect was manifest only in the axial plane in seven neonates. In the four instances in which the increased basal ganglia echogenicity was seen in both the coronal and axial planes, the effect was better shown in axial plane in all four. We did not observe any cases of increased echogenicity of the basal ganglia only in the coronal plane. The increased echogenicity was more conspicuous with the lower frequency transducer in 10 of the 11 examinations. We believe that the change in echogenicity of the basal ganglia is predominantly an anisotropic effect. Observing that increased echogenicity of the basal ganglia can disappear or decrease when comparing images in the axial to the coronal plane or be better demonstrated with lower frequency transducers might be a means by which to distinguish this phenomenon from true pathologic processes of the neonatal brain.  (+info)

Iron in the basal ganglia in Parkinson's disease. An in vitro study using extended X-ray absorption fine structure and cryo-electron microscopy. (7/1612)

Iron is found in high concentration in some areas of the brain, and increased iron in the substantia nigra is a feature of Parkinson's disease. The purpose of this study was to investigate the physical environment of brain iron in post-mortem tissue to provide information on the possible role of iron in neurodegeneration in Parkinson's disease. Iron has also been implicated as the cause of signal loss in areas of high brain iron on T2-weighted MRI sequences. Knowledge of the physical environment of the brain iron is essential in interpreting the cause of signal change. Post-mortem tissue was obtained from six cases of Parkinson's disease and from six age-matched controls. Iron levels were measured using absorption spectrophotometry. Extended X-ray absorption fine structure was used to evaluate the atomic environment of iron within the substantia nigra and both segments of the globus pallidus. Cryo-electron transmission microscopy was used to probe the iron storage proteins in these areas. Iron levels were increased in the parkinsonian nigra and lateral portion of the globus pallidus. Spectra from the extended X-ray absorption fine structure experiments showed that ferritin was the only storage protein detectable in both control and parkinsonian tissue in all areas studied. Cryo-electron transmission microscopy studies showed that ferritin was more heavily loaded with iron in Parkinson's disease when compared with age-matched controls. In summary we have shown that iron levels are increased in two areas of the brain in Parkinson's disease including the substantia nigra, the site of maximal neurodegeneration. This produces increased loading of ferritin, which is the normal brain iron storage protein. It is possible that increased loading of ferritin may increase the risk of free radical-induced damage. Differences in ferritin loading may explain regional differences in iron's effect on the T2 signal.  (+info)

Altered gene expression in striatal projection neurons in CB1 cannabinoid receptor knockout mice. (8/1612)

The basal ganglia, a brain structure critical for sensorimotor and motivational aspects of behavior, contain very high levels of CB1 cannabinoid receptors. These receptors are activated by endogenous lipophilic ligands, and they are thought to mediate behavioral effects of cannabinoid drugs. To evaluate the role of the endogenous cannabinoid system in the regulation of basal ganglia pathways, we have investigated the effects of targeted deletion of CB1 receptors on gene expression of various neuropeptides and transmitter-related enzymes in basal ganglia neurons. Mice without CB1 receptors are extremely hypoactive in a test for exploratory behavior (open-field test), showing markedly reduced locomotion and rearing. These CB1 mutants display significantly increased levels of substance P, dynorphin, enkephalin, and GAD 67 mRNAs in neurons of the two output pathways of the striatum that project to the substantia nigra and the globus pallidus. Our findings demonstrate that elimination of CB1 receptors results in behavioral abnormalities and functional reorganization of the basal ganglia.  (+info)

  • Beta oscillations in cortical-basal ganglia (BG) circuits have been implicated in normal movement suppression and motor impairment in Parkinson's disease. (nih.gov)
  • Basal ganglia disease is a group of physical dysfunctions that occur when the group of nuclei in the brain known as the basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function. (wikipedia.org)
  • New research shows that the basal ganglia can be modeled as a group of components of parallel, reentrant cortico-subcortical circuits, which originate in cortical areas, traverse the basal ganglia and terminate in specific areas in the frontal lobe. (wikipedia.org)
  • Understanding these circuits has led to breakthroughs in understanding the disorders of the basal ganglia. (wikipedia.org)
  • Parallel organization of functionally segregated circuits linking basal ganglia and cortex. (nih.gov)
  • Although the vibrissal circuits in the basal ganglia are poorly understood, many findings support the view that these circuits are involved in regulating the movements of the head, neck, and whiskers during a wide range of behaviors. (scholarpedia.org)
  • But neuroscience is shedding light on how circuits linking two parts of the brain, the basal ganglia and the frontal cortex, contribute to learning both productive and counterproductive behaviors, and even to some neurological disorders. (dana.org)
  • Our observations support a view that basal ganglia-related circuits directly implement behavioral adaptations that minimize errors and subsequently stabilize these adaptations by training premotor cortical areas. (pnas.org)
  • The mechanisms by which basal ganglia circuitry support motor learning are largely unknown, but evidence suggests that the basal ganglia are necessary to express recently learned behavior ( 12 ), and that changes in neural activity in response to learning appear first in basal ganglia circuits ( 13 , 14 ). (pnas.org)
  • Basal ganglia circuits are involved in various functions, including motor control and learning, sensorimotor integration, reward and cognition. (indigo.ca)
  • The rhythm effect appears to be a key feature of stuttering, providing a strong indication that stuttering is related to some type of disturbance of the basal ganglia motor circuits. (stutteringhelp.org)
  • However, despite our relatively detailed knowledge of basal ganglia biology and its connectivity with the cortex and numerical simulation studies demonstrating selective function, no formal theoretical framework exists that supplies an algorithmic description of these circuits. (mit.edu)
  • Conditions that cause injury to the brain can damage the basal ganglia. (medlineplus.gov)
  • Much of the output of the basal ganglia is directed at the primary motor cortex, and the motor nuclei of the brain stem . (everything2.com)
  • The Basal ganglia is a nuclei in the brain of the central nervous system which coordinates motor control and is involved in learning. (conservapedia.com)
  • Biotin-thiamine-responsive basal ganglia disease is a disorder that affects the nervous system, including a group of structures in the brain called the basal ganglia, which help control movement. (medlineplus.gov)
  • Using medical imaging, generalized swelling as well as specific areas of damage (lesions) in the brain can often be seen, including in the basal ganglia. (medlineplus.gov)
  • The "behavior switching" that takes place within the basal ganglia is influenced by signals from many parts of the brain, including the prefrontal cortex, which plays a key role in executive functions. (wikipedia.org)
  • Like most parts of the brain, the basal ganglia consist of left and right sides that are virtual mirror images of each other. (wikipedia.org)
  • The basal ganglia is a collective group of structures in the brain. (wikipedia.org)
  • The basal ganglia plays a role in a number of functions in the brain, including involuntary motor control and some cognitive functions. (reference.com)
  • An earthworm's ventral nerve cord carries signals from the brain to the body and allows for the coordination of the ganglia in each segment past the fourth. (reference.com)
  • Contributions to the volume from leading basal ganglia researchers altogether relate the neural architecture and functional circuitry of the basal ganglia, its interactions with other major systems of the brain, its neurotransmitter and signaling mechanisms, its role in multiple cognitive and behavioral domains and in various neurocognitive, neuropsychiatric and neurological disorders. (springer.com)
  • The basal ganglia, a group of interconnected brain areas located deep in the cerebral cortex, have proved to be at work in learning, the formation of good and bad habits, and some psychiatric and addictive disorders. (dnalc.org)
  • It is likely that the dopamine released in the basal ganglia system communicates with the brain areas in the prefrontal cortex to allow people to pay attention to critical tasks, ignore distracting information, and update only the most relevant task information in working memory during problem-solving tasks. (dnalc.org)
  • The experiments will investigate regional cerebral blood flow as an indicator of brain activity in human volunteers during specific learning tasks which are known from lesion studies to involve the basal ganglia. (europa.eu)
  • v) Given our knowledge on normal basal ganglia functions in animal and human motivation, how are the behavioural processes and brain mechanisms altered in human patients suffering from a number of basal ganglia diseases that constitute an important portion of brain pathologies and a serious challenge for human health and welfare? (europa.eu)
  • Surprise recruits a brain mechanism that globally suppresses motor activity, ostensibly via the subthalamic nucleus (STN) of the basal ganglia. (nih.gov)
  • The basal ganglia are a group of interconnected subcortical nuclei that represent one of the brain 's fundamental processing units. (scholarpedia.org)
  • New research is showing how the basal ganglia, deep inside the brain below the cortex, are important in learning from feedback, in the formation of good and bad habits, and even in brain disorders as diverse as Parkinson's disease, ADHD, and addiction. (dana.org)
  • For the first time, Carnegie Mellon University BrainHub scientists have used a non-invasive brain-imaging tool to detect the pathways that connect the parts of the basal ganglia. (eurekalert.org)
  • The output structures of the basal ganglia, including the substantia nigra pars reticulata (SNr) and entopeduncular nucleus (EPN), act as the interface of motor functions through their GABAergic inhibition of target brain regions. (jneurosci.org)
  • The "behavior switching" that takes place within the basal ganglia is influenced by signals from many parts of the brain, including the prefrontal cortex , which is widely believed to play a key role in executive functions . (thefullwiki.org)
  • Coronal slices of human brain showing the basal ganglia. (thefullwiki.org)
  • In the illustration to the right, two coronal sections of the human brain show the location of the basal ganglia. (thefullwiki.org)
  • A growing number of studies show that the role and anatomical connection in each area of the basal ganglia is well organized along the brain axes, the rostral-caudal axis and medial-lateral axis. (frontiersin.org)
  • This Research Topic aims to collect a wide range of articles on the anatomical connections and the heterogeneous functions organized over the axes of basal ganglia in various brain research models. (frontiersin.org)
  • The group of brain structures that help control body motions is called the basal ganglia. (sharecare.com)
  • As the brain plans and coordinates movements, information-in the form of electrical brain activity-flows between the structures within the basal ganglia. (sharecare.com)
  • In this article I will focus on the main theoretical work, regarding the possible relation between stuttering and the basal ganglia, brain structures involved in automatization (Alm, 2004). (stutteringhelp.org)
  • In particular the basal ganglia are complex networks of the brain that control someaspects of movement in all vertebrates. (diva-portal.org)
  • However, despite intensive study, both the internal computational mechanisms of the basal ganglia, and their contribution to normal brain function, have been elusive. (uwaterloo.ca)
  • The basal ganglia are a part of the brain. (healthtap.com)
  • Coloured Positron Emission Tomography (PET) scan of a healthy brain, viewed at basal ganglia level. (sciencephoto.com)
  • The primitive brain stem, called the basal ganglia, which we share with animal forms as low as reptiles, controls impulses essential to survival. (socionomics.net)
  • Below you will find a brief overview of a portion of the brain known as the basal ganglia. (lawfitz.com)
  • The basal ganglia are actually located in two different areas of the brain. (lawfitz.com)
  • The work is also important for brain modelling, in particular to model c ortex viewed as a dynamical system whose dynamics is regulated by basal ganglia. (cnr.it)
  • The importance of this resides in the fact that the basal-ganglia and cortex form segregated loops that are a fundamental building module underlying multiple brain processes, from associative sensory processing, to motor behaviour, thinking, plannig, and reasoning. (cnr.it)
  • Here, Japanese research team led by Prof Atsushi Nambu and Dr Satomi Chiken of National Institute for Physiological Sciences (NIPS) in Japan, with Dr. Pullanipally Shashidharan of Mt Sinai School of Medicine in USA, has found that the decreased activity of the basal ganglia, a part of the brain structure, is the main cause of abnormal muscle constrictions of dystonia using a mouse model. (bio-medicine.org)
  • In more specific terms, the basal ganglia's primary function is likely to control and regulate activities of the motor and premotor cortical areas so that voluntary movements can be performed smoothly. (wikipedia.org)
  • While most of this information comes from the vibrissal regions in the primary somatosensory (SI) and motor (MI) cortical areas, some whisker information is transmitted much more rapidly to the basal ganglia by intralaminar and other thalamic nuclei. (scholarpedia.org)
  • A series of interconnected nuclei in the basal ganglia transform these whisker-related inputs, and the processed output is then sent to other thalamic nuclei that project to several cortical areas. (scholarpedia.org)
  • In turn, the basal ganglia affect activity in the frontal cortex through a series of neural projections that ultimately go back up to the same cortical areas from which they received the initial input. (dana.org)
  • The basal ganglia consist of interconnected nuclei, which process the information received from different cortical and sub-cortical areas. (frontiersin.org)
  • In the case of highly practiced tasks, these regions include cortical areas hypothesized to integrate evidence supporting alternative actions and the basal ganglia, hypothesized to act as a central switch in gating behavioral requests. (mit.edu)
  • Further, we show that this neurobiologically grounded implementation of MSPRT outperforms other candidates for neural decision making, that it is structurally and parametrically robust, and that it can accommodate cortical mechanisms for decision making in a way that complements those in basal ganglia. (mit.edu)
  • This process begins with a review of two current hypotheses of normal basal ganglia function, one being that they automatically select actions on the basis of past reinforcement, and the other that they compress cortical signals that tend to occur in conjunction with reinforcement. (uwaterloo.ca)
  • However, in the dystonia mouse model, the neuronal activity is decreased so that basal ganglia cannot inhibit motor cortical activity related to unnecessary movements. (bio-medicine.org)
  • The cerebellum, basal ganglia (BG), and other cortical regions, such as supplementary motor area (SMA) have emerged as important structures dealing with various aspects of timing, yet the modulation of functional connectivity between them during motor timing tasks remains unexplored. (unboundmedicine.com)
  • Electrophysiological evidences of organization of cortical motor information in the Basal Ganglia. (biomedsearch.com)
  • This review discusses the in vivo electrophysiology of basal ganglia (BG), thalamic, and cortical regions after dopamine-depleting lesions. (iospress.com)
  • The basal ganglia (BG) and the cerebellum historically have been relegated to a functional role in producing or modulating motor output. (medscape.com)
  • The basal ganglia (BG) and the cerebellum traditionally have been assigned to roles within the motor domain, yet recent research has recognized their contributions to a variety of functions, including affective processing. (medscape.com)
  • Hypomyelination with atrophy of the basal ganglia and cerebellum: follow-up and pathology. (biomedsearch.com)
  • BACKGROUND AND OBJECTIVE: Hypomyelination with atrophy of the basal ganglia and cerebellum is a recently defined disorder. (biomedsearch.com)
  • CONCLUSION: Hypomyelination with atrophy of the basal ganglia and cerebellum is a syndrome diagnosed by distinctive MRI findings. (biomedsearch.com)
  • Subcortical loops through the basal ganglia and the cerebellum form computationally powerful distributed processing modules (DPMs). (royalsocietypublishing.org)
  • Once a tentative pattern has been selected and initiated through the operation of the loops through the basal ganglia, the loops through the cerebellum amplify and sculpt that pattern into a refined output vector ( Houk & Mugnaini 2003 ). (royalsocietypublishing.org)
  • This paper presents a sensorimotor architecture integrating computational models of a cerebellum and a basal ganglia and operating on a microrobot. (spie.org)
  • The basal ganglia model uses the visual inputs to develop sensorimotor mapping for motor control, while the cerebellum module uses robot orientation and world- coordinate transformed inputs to predict the location of the moving object in a robot centered coordinate system. (spie.org)
  • General Functional Significance of the Basal Ganglia A. Involved in the regulation of movement: through direct and indirect connections with the cerebral cortex, the basal ganglia influence descending motor systems (e.g., corticospinal and corticobulbar). (scribd.com)
  • The basal ganglia are a collection of interconnected areas deep below the cerebral cortex. (dana.org)
  • We come to posit that the many loops through the basal ganglia each regulate the embodiment of pattern formation in a given area of cerebral cortex. (royalsocietypublishing.org)
  • The subthalamic nucleus (STN) is a key component of basal ganglia circuitry that mediates a variety of motor functions. (jneurosci.org)
  • The model suggests that a subsystem of the basal ganglia is in charge of resolvingconflicts between motor programs suggested by different motor centers in the nervous system.This subsystem that is composed of the subthalamic nucleus and pallidum is called thearbitration system. (diva-portal.org)
  • The muscle rigidity, tremor at rest, and slowness in initiation and execution of movement that are the cardinal motor symptoms of Parkinson's disease are attributed to a reduction in dopaminergic activity in the basal ganglia motor areas, particularly the putamen, due to gradually reduced innervation from SNc. (wikipedia.org)
  • T1 signal intensity in extra-pallidal basal ganglia (caudate and putamen) has not been studied in occupationally exposed workers. (bmj.com)
  • Combined basal ganglia (ρ=0.610), caudate (ρ=0.645), anterior (ρ=0.595) and posterior putamen (ρ=0.511) indices were more correlated with exposure than pallidal (ρ=0.484) index. (bmj.com)
  • Combined basal ganglia, caudate and putamen indices were more correlated with exposure than pallidal index suggesting more inclusive basal ganglia sampling results in better exposure markers. (bmj.com)
  • 2002). Inputs external to the basal ganglia derive not only from large parts of frontal cortex, but also from various thalamic and brainstem structures. (scholarpedia.org)
  • We present a patient with a large bilateral basal ganglia and thalamic AVM successfully treated with hypofractionated stereotactic radiosurgery (HFSRS) with intensity modulated radiotherapy (IMRT). (hindawi.com)
  • Large bilateral thalamic and basal ganglia AVMs can be successfully treated with complete obliteration by HFSRS with IMRT with relatively limited toxicity. (hindawi.com)
  • Neonatal basal ganglia and thalamic volumes were positively related to motor, intelligence quotient, and academic outcomes at age 7 years, with mostly similar relationships in the VP and control groups.ConclusionVP birth results in smaller basal ganglia and thalamic volumes at term-equivalent age, and these smaller volumes are related to a range of 7-year neurodevelopmental deficits in VP children. (nih.gov)
  • Basal ganglia calcifications (BGC) may be present in various medical conditions, such as infections, metabolic, psychiatric and neurological diseases, associated with different etiologies and clinical outcomes, including parkinsonism, psychosis, mood swings and dementia. (scielo.br)
  • This article shows how many aspects of the anatomy and physiology of the circuit involving the cortex and basal ganglia are exactly those required to implement the computation defined by an asymptotically optimal statistical test for decision making: the multihypothesis sequential probability ratio test (MSPRT). (mit.edu)
  • Damage to the basal ganglia cells may cause problems controlling speech, movement, and posture. (medlineplus.gov)
  • Damage to the basal ganglia produces severe deficit s in motor ability, but the neuron al activation in the basal ganglia indicates that they do not specfically direct the muscular movements, nor are they involved in stimulus-triggered movement . (everything2.com)
  • Patients with damage to the basal ganglia often have deficits in movement," says Michael Frank, a neuroscientist at the University of Arizona. (dnalc.org)
  • For instance, damage to the basal ganglia could lead to symptoms that include involuntary muscle movements and dystonia, which is a condition whereby the tone in the muscle tissue in the body fluctuates. (lawfitz.com)
  • Experimental studies show that the basal ganglia exert an inhibitory influence on a number of motor systems, and that a release of this inhibition permits a motor system to become active. (wikipedia.org)
  • The aim of this collection of articles is to find a fundamental principle for the functions of the basal ganglia separated by the anatomical axes. (frontiersin.org)
  • The connections between the basal ganglia and the substantia nigra suggest that the basal ganglia may play a role in the plan ning and initiation of self-triggered (i.e. voluntary ) movement. (everything2.com)
  • Convergent lines of evidence suggest that the basal ganglia are importantly involved in the control of voluntary, goal-directed behaviour. (europa.eu)
  • Many of the novel research techniques that have helped reveal the complex neural architecture and functional diversity of the basal ganglia are also given view. (springer.com)
  • Of course, this machinery is inordinately intricate and complex, The more a behavior is ingrained, the more its neural representations in the basal ganglia are strengthened and honed. (dana.org)
  • This circuit enables the basal ganglia to transform and amplify the pattern of neural firing in the frontal cortex that is associated with adaptive, or appropriate, behaviors, while suppressing those that are less adaptive. (dana.org)
  • Basal ganglia disfunction is also implicated in some other disorders of behavior control such as Tourette's syndrome and obsessive-compulsive disorder , although the neural mechanisms underlying these are not well understood. (thefullwiki.org)
  • We welcome Orignal Research and Review articles focused on the function of a specific area of the basal ganglia, as well as articles on the comparison between the roles and neural connections of different basal ganglia areas. (frontiersin.org)
  • Although no one found gross physical lesions in people with obsessive-compulsive disorder or schizophrenia, often the basal ganglia were implicated by abnormal metabolic activity in the region," says Ann Graybiel, a leading researcher in the function of basal ganglia at the Massachusetts Institute of Technology. (dnalc.org)
  • The experiments will be done with lesions of specific nuclei of the basal ganglia of rats and monkeys which learn and perform specific tasks involving basal ganglia mechanisms of reward processing and procedural motor and habit learning. (europa.eu)
  • Lesions of the basal ganglia occur in a variety of motor disorders. (emf-portal.org)
  • Yao and colleagues retrospectively gathered a dataset of 316 patients diagnosed with basal ganglia infarction at their institution between September 2016 and June 2019. (auntminnie.com)
  • All infarction sections of the basal ganglia on the CT exams were segmented by a radiologist with over 30 years of experience and were validated by a radiologist with over 10 years of experience, as well as two clinical students. (auntminnie.com)
  • Neuroimaging findings of MRI and SPECT successfully revealed cerebral infarction in the right basal ganglia region and decreased cerebral blood flow in the right frontal lobe (remote effect). (omicsonline.org)
  • 7mm ovoid lesion fluid density shown within posterior inferior aspect of right basal ganglia small vessel coursing through it incidental virchow robin? (healthtap.com)
  • On the biological side, the model architecture reflects the anatomical organisation of cortico-basal ganglia circuites and exhibits behaviours that are qualitatively comparable with those of humans (e.g., movements produced by normal people, or movements produced by Parkinson patients when the system is suitably lesioned). (cnr.it)
  • Since the nucleic structure of the basal ganglia are thought to be involved in emotional functioning, disorders in this area can cause emotional and personality abnormalities such as paranoia, depression or abnormal behavior. (home-remedies-for-you.com)
  • In addition to their role in control of movement and posture, it now appears that the basal ganglia also play a more complex (cognitive) aspects of behavior and may be involved in limbic functions. (cerebromente.org.br)
  • Like many learning tasks in mammals ( 4 ⇓ - 6 ), this goal-directed behavior requires a basal ganglia-thalamocortical circuit ( Fig. 1 A ) known as the anterior forebrain pathway (AFP) ( 7 ⇓ ⇓ ⇓ - 11 ). (pnas.org)
  • Given the complex circuitry of the basal ganglia, research has suggested that they also are a coordination system. (dnalc.org)
  • It has recently been shown that a basal ganglia-forebrain circuit in the songbird, which projects directly to vocal-motor circuitry, has a premotor function driving exploration necessary for vocal learning. (pnas.org)
  • At centre and centre right are two pairs of basal ganglia (yellow ovals), nerve cell clusters deep in the cerebrum & upper part of the brainstem. (sciencephoto.com)
  • For example, the substantia nigra pars compacta provides critically important dopaminergic innervation and several raphe nuclei give rise to serotonin input to the basal ganglia. (dartmouth.edu)
  • Extrinsic Outputs from the basal ganglia arise mainly from the globus paliidus and substantia nigra pars reticula TO: 1. (scribd.com)
  • The basal ganglia have a limbic sector whose components are assigned distinct names: the nucleus accumbens, ventral pallidum, and ventral tegmental area (VTA). (wikipedia.org)
  • The area has a number of pathways that loop not only through the basal ganglia, but also through the prefrontal association cortex and the limbic cortex. (reference.com)
  • February 11, 2020 -- The combination of radiomics and a machine-learning algorithm can determine on CT if an ischemic stroke in the basal ganglia occurred within the window of time in which a stroke patient can still receive thrombolysis, according to research published online February 10 in the Journal of the Neurological Sciences . (auntminnie.com)
  • The basal ganglia play a central role in a number of neurological conditions, including several movement disorders . (thefullwiki.org)
  • Along with the assistance that the basal ganglia gives to the body's movements, it also plays a factor in a number of cognitive processes. (reference.com)
  • Reported is the change in cognitive function after neuronal cell transplantation as a treatment for basal ganglia stroke. (neurology.org)
  • Despite the persistence of these monoamine and behavioral deficits, the long-term impact of psychostimulant-induced damage to central monoamine systems on basal ganglia function and the alterations in central nervous system function underlying the cognitive and motor deficits are unknown. (aspetjournals.org)
  • We plan to study how the motivational control of behaviour is achieved by neuronal mechanisms operating in the basal ganglia. (europa.eu)
  • iii) Can we find single neurone correlates in the basal ganglia for specific motivational processes defined above, notably the processing of reward information and mechanisms underlying particular forms of learning? (europa.eu)
  • Although the basal ganglia process tactile information produced by passive whisker stimulation, scientific interest in using the whisker system to understand the functional mechanisms of the basal ganglia has focused on the active whisking system of rats and mice. (scholarpedia.org)
  • In the thesis, On the causal mechanisms of stuttering (Alm, 2005), the basal ganglia model was developed further, based on the theoretical work on the human motor system proposed by Goldberg (1985, 1991) and others. (stutteringhelp.org)
  • reasons for abnormal increases or decreases of basal ganglia output are poorly understood. (wikipedia.org)
  • Dysfunctions of the Basal Ganglia : Abnormal movements are commonly caused by a release of the system from inhibition. (scribd.com)
  • Decreased activity of basal ganglia is the main cause of abnormal muscle constrictions i. (bio-medicine.org)
  • If we can artificially increase basal ganglia activity, abnormal muscle constrictions in dystonia patients could be well controlled", said Prof Nambu and Dr Chiken. (bio-medicine.org)
  • These results suggest that surprise interrupts cognition via the same fronto-basal ganglia mechanism that interrupts action. (nih.gov)
  • In species such as rats and mice, the vibrissal basal ganglia circuit is a subcomponent of the sensorimotor channel in the basal ganglia network. (scholarpedia.org)
  • Mri found bilaterally along the inferior lateral aspect of the basal ganglion, either old lacunar infarctions or bilateral benign cysts. (healthtap.com)
  • subacute infarcts, bilateral frontal lobes, small vessel ischematic changes inthe basal ganglia, periventricular white matter? (healthtap.com)