Vestibular Nuclei: The four cellular masses in the floor of the fourth ventricle giving rise to a widely dispersed special sensory system. Included is the superior, medial, inferior, and LATERAL VESTIBULAR NUCLEUS. (From Dorland, 27th ed)Vestibular Nucleus, Lateral: Vestibular nucleus lying immediately superior to the inferior vestibular nucleus and composed of large multipolar nerve cells. Its upper end becomes continuous with the superior vestibular nucleus.Vestibular Nerve: The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.Vestibule, Labyrinth: An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Motion Sickness: Disorder caused by motion, as sea sickness, train sickness, car sickness, air sickness, or SPACE MOTION SICKNESS. It may include nausea, vomiting and dizziness.Reflex, Vestibulo-Ocular: A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.Otolithic Membrane: A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.Anatomy, Regional: The anatomical study of specific regions or parts of organisms, emphasizing the relationship between the various structures (e.g. muscles, nerves, skeletal, cardiovascular, etc.).Ear, Inner: The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.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.Cerebellar Nuclei: Four clusters of neurons located deep within the WHITE MATTER of the CEREBELLUM, which are the nucleus dentatus, nucleus emboliformis, nucleus globosus, and nucleus fastigii.Neuroanatomical Tract-Tracing Techniques: Methods used to label and follow the course of NEURAL PATHWAYS by AXONAL TRANSPORT of injected NEURONAL TRACT-TRACERS.Head Movements: Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.Neuronal Tract-Tracers: Substances used to identify the location and to characterize the types of NEURAL PATHWAYS.Histamine Agents: Drugs used for their actions on histaminergic systems. Included are drugs that act at histamine receptors, affect the life cycle of histamine, or affect the state of histaminergic cells.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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.Semicircular Canals: Three long canals (anterior, posterior, and lateral) of the bony labyrinth. They are set at right angles to each other and are situated posterosuperior to the vestibule of the bony labyrinth (VESTIBULAR LABYRINTH). The semicircular canals have five openings into the vestibule with one shared by the anterior and the posterior canals. Within the canals are the SEMICIRCULAR DUCTS.Vestibular Neuronitis: Idiopathic inflammation of the VESTIBULAR NERVE, characterized clinically by the acute or subacute onset of VERTIGO; NAUSEA; and imbalance. The COCHLEAR NERVE is typically spared and HEARING LOSS and TINNITUS do not usually occur. Symptoms usually resolve over a period of days to weeks. (Adams et al., Principles of Neurology, 6th ed, p304)Nystagmus, Pathologic: Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)Nystagmus, Physiologic: Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.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)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.Trigeminal Nuclei: Nuclei of the trigeminal nerve situated in the brain stem. They include the nucleus of the spinal trigeminal tract (TRIGEMINAL NUCLEUS, SPINAL), the principal sensory nucleus, the mesencephalic nucleus, and the motor nucleus.Solanaceous Alkaloids: Alkaloids, mainly tropanes, elaborated by plants of the family Solanaceae, including Atropa, Hyoscyamus, Mandragora, Nicotiana, Solanum, etc. Some act as cholinergic antagonists; most are very toxic; many are used medicinally.Eye Movements: Voluntary or reflex-controlled movements of the eye.Brain Stem Infarctions: Infarctions that occur in the BRAIN STEM which is comprised of the MIDBRAIN; PONS; and MEDULLA OBLONGATA. There are several named syndromes characterized by their distinctive clinical manifestations and specific sites of ischemic injury.Abducens Nerve: The 6th cranial nerve which originates in the ABDUCENS NUCLEUS of the PONS and sends motor fibers to the lateral rectus muscles of the EYE. Damage to the nerve or its nucleus disrupts horizontal eye movement control.Stomatognathic System: The mouth, teeth, jaws, pharynx, and related structures as they relate to mastication, deglutition, and speech.Oculomotor Nerve: The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.Vestibulocochlear Nerve: The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.Caloric Tests: Elicitation of a rotatory nystagmus by stimulating the semicircular canals with water or air which is above or below body temperature. In warm caloric stimulation a rotatory nystagmus is developed toward the side of the stimulated ear; in cold, away from the stimulated side. Absence of nystagmus indicates the labyrinth is not functioning.Pons: The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.Raphe Nuclei: Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.Neural Pathways: Neural tracts connecting one part of the nervous system with another.PropiophenonesAction Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Medulla Oblongata: The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.Acceleration: An increase in the rate of speed.Saimiri: A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Nucleus Accumbens: Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.Vestibular Diseases: Pathological processes of the VESTIBULAR LABYRINTH which contains part of the balancing apparatus. Patients with vestibular diseases show instability and are at risk of frequent falls.Copper Sulfate: A sulfate salt of copper. It is a potent emetic and is used as an antidote for poisoning by phosphorus. It also can be used to prevent the growth of algae.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.Reticular Formation: A region extending from the PONS & MEDULLA OBLONGATA through the MESENCEPHALON, characterized by a diversity of neurons of various sizes and shapes, arranged in different aggregations and enmeshed in a complicated fiber network.Betahistine: A histamine analog and H1 receptor agonist that serves as a vasodilator. It is used in MENIERE DISEASE and in vascular headaches but may exacerbate bronchial asthma and peptic ulcers.Iontophoresis: Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.Receptors, Histamine H3: A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H3 receptors were first recognized as inhibitory autoreceptors on histamine-containing nerve terminals and have since been shown to regulate the release of several neurotransmitters in the central and peripheral nervous systems. (From Biochem Soc Trans 1992 Feb;20(1):122-5)Thalamic Nuclei: Several groups of nuclei in the thalamus that serve as the major relay centers for sensory impulses in the brain.5,7-Dihydroxytryptamine: Tryptamine substituted with two hydroxyl groups in positions 5 and 7. It is a neurotoxic serotonin analog that destroys serotonergic neurons preferentially and is used in neuropharmacology as a tool.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Solitary Nucleus: GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein.Consciousness: Sense of awareness of self and of the environment.Vertigo: An illusion of movement, either of the external world revolving around the individual or of the individual revolving in space. Vertigo may be associated with disorders of the inner ear (EAR, INNER); VESTIBULAR NERVE; BRAINSTEM; or CEREBRAL CORTEX. Lesions in the TEMPORAL LOBE and PARIETAL LOBE may be associated with FOCAL SEIZURES that may feature vertigo as an ictal manifestation. (From Adams et al., Principles of Neurology, 6th ed, pp300-1)Biotin: A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.Purkinje Cells: The output neurons of the cerebellar cortex.Cochlear Nucleus: The brain stem nucleus that receives the central input from the cochlear nerve. The cochlear nucleus is located lateral and dorsolateral to the inferior cerebellar peduncles and is functionally divided into dorsal and ventral parts. It is tonotopically organized, performs the first stage of central auditory processing, and projects (directly or indirectly) to higher auditory areas including the superior olivary nuclei, the medial geniculi, the inferior colliculi, and the auditory cortex.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Hypoglossal Nerve: The 12th cranial nerve. The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus). This nerve also contains proprioceptive afferents from the tongue muscles.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.Dextrans: A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.

*  KNES462 d7 copy - Distal proximal rule applies also here 37 KNES 462 FK

... from lateral vestibular nucleus) proximal ---run contralaterally. • Distal - ... l muscles (from medial vestibular nucleus) - Or to distal muscles ( ... Unformatted text preview: l muscles (from medial vestibular nucleus) - Or to distal muscles (from lateral vestibular nucleus) ... push-pull' mechanism • cranial nerve VIII projects to the vestibular nucleus in the brainstem - vestibular nucleus has ...

*  Vestibular nucleus legal definition of vestibular nucleus

What is vestibular nucleus? Meaning of vestibular nucleus as a legal term. What does vestibular nucleus mean in law? ... Definition of vestibular nucleus in the Legal Dictionary - by Free online English dictionary and encyclopedia. ... Vestibular nucleus legal definition of vestibular nucleus https://legal-dictionary.thefreedictionary.com/vestibular+nucleus ... nucleus. (redirected from vestibular nucleus). Also found in: Dictionary, Thesaurus, Medical, Encyclopedia. See: center, ...

*  Vestibular nuclei - Wikipedia

The vestibular nuclei are the cranial nuclei for the vestibular nerve. In Terminologia Anatomica they are grouped in both the ... The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue. Primary terminal nuclei ... Fibres from the lateral vestibular nucleus also pass via the vestibulospinal tract, to anterior horn cells at many levels in ... Some of the axons of the cells of the lateral nucleus, and possibly also of the medial nucleus, are continued upward through ...

*  Medial vestibular nucleus - Wikipedia

The medial vestibular nucleus is one of the vestibular nuclei. It is located in the medulla oblongata. Lateral vestibulo-spinal ... Vestibular nerve Vestibular system This article incorporates text in the public domain from the 20th edition of Gray's Anatomy ... lateral vestibular nucleus "Deiters")- via ventrolateral medulla and spinal cord to ventral funiculus (lumbo-sacral segments ... vestibular nuclei), bilateral projection via descending medial longitudinal fasciculus to cervical segments. DESCENDING MLF.. ...

*  Inferior vestibular nucleus - Wikipedia

The inferior vestibular nucleus is the vestibular nucleus which lies near the fourth ventricle. https://web.archive.org/web/ ...

*  Superior vestibular nucleus - Wikipedia

The superior vestibular nucleus (Bechterew's nucleus) is the dorso-lateral part of the vestibular nucleus and receives ... collaterals and terminals from the ascending branches of the vestibular nerve. Sends uncrossed fibers to cranial nerve 3 and 4 ...

*  Lateral vestibular nucleus - Wikipedia

The lateral vestibular nucleus (Deiters's nucleus) is the continuation upward and lateralward of the principal nucleus, and in ... Deiter's nucleus was named after German neuroanatomist Otto Friedrich Karl Deiters (1834-1863). This article incorporates text ... Other axons from Deiters's nucleus are supposed to cross and ascend in the opposite medial lemniscus to the ventro-lateral ... according to Cajal they merely pass through the nucleus fastigii on their way to the cortex of the vermis and the hemisphere. ...

*  Pompeiano, O. [WorldCat Identities]

Innervation Vestibular apparatus Vestibular apparatus--Diseases Vestibular function tests Vestibular nuclei ... The vestibular nuclei and their connections; anatomy and functional correlations by Alf Brodal( Book ). 10 editions published ... The Vestibular Nuclei and their Connections, Anatomy and Functional Correlations. [By] A. Brodal, Ottavio Pompeiano, Fred ... Vestibular system; Part 1: Basic mechanisms by Dan Bagger-Sjöbäck( ). 1 edition published in 1974 in English and held by 0 ...

*  Brain Development and Anatomy 1

to deep cerebellar and lateral vestibular nuclei inner granular layer [input]. functional considerations ...

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1968) Organisation of the medial vestibular nucleus. J Neurophysiol 31:166-175. ... XII, Hypoglossal nucleus. The tip positions are visible in B and D, which show the regions marked by boxes from A and C at ... However, these are less common in primate and their terminals in the lateral reticular nucleus are also laterally positioned, ... 1969) Comparison of effects of stimulation of Deiters' nucleus and medial longitudinal fasciculus on neck, forelimb and ...

*  Nystagmus In Infancy and Childhood - Richard W. Hertle, Louis F. Dell'Osso - Oxford University Press

1.2.3 Brainstem Nuclei. 1.2.4 Vestibular Nuclei. 1.2.5 Cerebellum. 1.3 AFFERENT SYSTEM. 1.3.1 Retina/Optic Nerve. 1.3.2 Optic ... 5.2.1 Vestibular Nystagmus. 5.2.1.1 Peripheral Vestibular Imbalance. 5.2.1.2 Central Vestibular Imbalance. 5.2.1.3 Central ... 3.1.1.1 Types (FMNS plus Nucleus of the Optic Tract). 3.1.1.2 The Fixating Eye. 3.1.1.3 Target Foveation and Dual-Mode Fast ... 2.2.3.2 Tonic Vestibular-Optokinetic Imbalance. 2.3 VISUAL FUNCTION DEFICITS AND MEASUREMENTS OF INS. 2.3.1 Static Deficits. ...

*  The Vestibular System - Jay M. Goldberg; Victor J. Wilson; Kathleen E. Cullen; Dora E. Angelaki; Dianne M. Broussard; Jean...

The vestibular system plays a vital role in everyday life, contributing to a surprising range of functions from reflexes to the ... In The Vestibular System: A Sixth Sense, leading experts present an integrative, comprehensive and innovative look at the sense ... Medial vestibular nucleus (MVN). Lateral vestibular nucleus (LVN). Superior vestibular nucleus (SVN). Descending vestibular ... Fastigial Nucleus.. Rostral fastigial nucleus. Caudal fastigial nucleus. The interposed nuclei.. Dentate nuclei.. 12.6 Summary ...

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2009), whereas in others, including cerebellar Purkinje neurons (Raman and Bean 1997; this study), vestibular nucleus neurons ( ... Mechanisms of sustained high firing rates in two classes of vestibular nucleus neurons: differential contributions of resurgent ... vestibular nucleus neurons (Gittis et al. 2010), and cortical GABAergic interneurons (Carter and Bean 2009). In principle, the ... such as in the medial vestibular nucleus (Gittis et al. 2010).. During repetitive firing of action potentials, voltage- ...

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1995) Cellular processing of temporal information in medial vestibular nucleus neurons. J Neurosci 15:8000-8010. ...

*  Sustained cortical and subcortical neuromodulation induced by electrical tongue stimulation | SpringerLink

Organisation of reciprocal connections between trigeminal and vestibular nuclei in the rat. Journal of Comparative Neurology, ... 2003). Use of electrical vestibular stimulation to alter genioglossal muscle activity in awake cats. Journal of Vestibular ... Efficacy of electrotactile vestibular substitution in patients with bilateral vestibular and central balance loss. Conference ... Efficacy of electrotactile vestibular substitution in patients with peripheral and central vestibular loss. Journal of ...

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... superior vestibular nucleus; BC, brachium conjuctivum; NRT, nucleus reticularis tegmenti pontis; NTB, nucleus of the trapezoid ... nucleus cuneiformis;NCS, nucleus centralis superior; NL, nuclei of the lateral lemniscus; NRPo, nucleus reticularis pontis ... Thin solid lines delimit the reticular core and other pontine nuclei. Vp, Principal sensory nucleus of the trigeminal nerve; ... oralis; NRT, nucleus reticularis tegmenti pontis; PDB, predorsal bundle;PN, pontine nuclei; VT, ventral tegmental nucleus (of ...

*  KAKEN - Research Projects | Mechanisms of protectiion by neurotrophins against NO-mediated glutamate neurotoxicity (KAKENHI...

Ethanol reduces spontaneous iring and potentiates GABA-induced currents in acutely dis-sociated rat medial vestibular nucleus ... Ethanol reduces spontaneous firing and potentiates GABA-induced currents in acutely dissoci-ated rat medial vestibular nucleus ... Ethanol reduces spontaneous iring and potentiates GABA-induced currents in acutely dissoci-ated rat medial vestibular nucleus ...

*  9780444500120 - Equilibrium Research, Clinical | eCampus.com

Neuronal function in medial vestibular nucleus during hypoxia: role of glutamate in the hypoxia-induced depolarization. ... Localization of cerebral cortical neurons that project to the rat vestibular nuclei: a HRP study. ... Postnatal development of resting discharge of otolith neurons in rat vestibular nucleus. ... Robert B_r_ny who clarifie d the physiology and pathology of the human vestibular apparatus and w as awarded the Nobel Prize ...

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1995) Postsynaptic targets of Purkinje cell terminals in the cerebellar and vestibular nuclei of the rat. Eur J Neurosci 7:2322 ... CS and US inputs reach both the cerebellar cortex and deep nuclei, and excitation of the red nucleus by the deep nuclei drives ... would allow deep nuclei to excite the red nucleus and the CR could ensue. ... 1997) The cerebellum and red nucleus are not required for in vitro classical conditioning of the turtle abducens nerve response ...

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For example, while the vestibular nuclei, spinal cord, and pontine nuclei also send MF afferents to IXcd (Freedman et al., 1975 ... 1994) Projections of individual Purkinje cells of identified zones in the flocculus to the vestibular and cerebellar nuclei in ... 2012) Distribution of zebrin-immunoreactive Purkinje cell terminals in the cerebellar and vestibular nuclei of birds. J Comp ... 2010) showed that MF inputs from two retinorecipient nuclei in pigeons that are responsive to optic flow, the pretectal nucleus ...

*  PPT - Physiology of Motor Tracts PowerPoint Presentation - ID:5590802

Vestibular Apparatus are essentialdetects changes head position )  *sends fibers to Vestibular Nuclei in Pons + to Cerebellum ... Fibers originate in vestibular nuclei in pons (which receive inputs from inner ear Vestibular Apparatus and Vestibulocerebellum ... Vestibular nuclei tracts are always excitatory to Gamma Efferents ( whereas Red nucleus is always inhibitory) ... The medial longitudinal fasciculus consists of both ascending & descending fibers that link vestibular nuclei to nuclei ...

*  Distribution of cholinergic cells in guinea pig brainstem

medial vestibular nucleus. MVeMC. medial vestibular nucleus, magnocellular. MVePC. medial vestibular nucleus, parvicellular. ... oculomotor nucleus. 4. trochlear nucleus. 4n. 4th nerve. 5. motor nucleus of 5th nerve. 6. abducens nucleus. 7. facial nucleus ... vestibular root of 8th nerve. 10. dorsal motor nucleus of the vagus. Amb. nucleus ambiguus. APT. anterior pretectal nucleus. Aq ... lateral reticular nucleus. LSO. lateral superior olive. LTB. lateral nucleus of trapezoid body. LVe. lateral vestibular nucleus ...

*  Radiologie en Medische Beeldvorming Archives - azlink

Imaging of the cochlear and vestibular nuclei.. Kyrenia, Cyprus. 5-7/04/2013 ... Bilateral otospongiosis and a unilateral vestibular schwannoma in a patient with Myhre.. Otol Neurotol, Epub, 2014; 35:253-255 ... Bilateral otospongiosis and a unilateral vestibular schwannoma in a patient with Myhre.. Otol Neurotol, Epub, 2014. 01/01/2014 ...

*  Pharmacological tests of hypotheses for acquired pendular nystagmus

... the neural integrator in the vestibular nuclei and nucleus prepositus hypoglossi.. Injection of the GABA agonist muscimol into ... but not due to downstream signal modulation by pre-motor neurons in the vestibular nuclei.8 ... APN in OPT is attributed to hypertrophic degeneration of the inferior olivary nucleus (IO) following a breach in the "Guillain- ... Baclofen, which is known to reduce the excitability of pre-motor vestibular neurons via a GABAergic mechanism, did not alter ...

*  PPT - Case Study PowerPoint Presentation - ID:6725851

Vestibular nuclei connect to the cerebellum, MLF (eye movement) and the vestibulospinal tract ... Visual, proprioceptive, and vestibular systems maintain position (Romberg test) *Semicircular canals connect to the vestibular ... nuclei in the brainstem via CN VIII * ...

Medial vestibular nucleus: The medial vestibular nucleus is one of the vestibular nuclei. It is located in the medulla oblongata.SeasicknessVision in fishes: Vision is an important sensory system for most species of fish. Fish eyes are similar to terrestrial vertebrates like birds and mammals, but have a more spherical lens.Otolith: An otolith (οτο-, oto-, ear + λιθος, lithos, a stone), also called statoconium or otoconium, is a structure in the saccule or utricle of the inner ear, specifically in the vestibular labyrinth of vertebrates. They have been identified in both extinct and extant vertebrates.Parallel curveCentral tegmental tract: The central tegmental tractKamali A, Kramer LA, Butler IJ, Hasan KM. Diffusion tensor tractography of the somatosensory system in the human brainstem: initial findings using high isotropic spatial resolution at 3.Interposed nucleus: The interposed nucleus is a deep nucleus of the cerebellum and is composed of the globose nuclei and the emboliform nuclei. It is located in the roof (dorsal aspect) of the fourth ventricle, lateral to the fastigial nucleus.Fall Heads Roll: Fall Heads Roll is an album by The Fall, released in 2005. It was recorded at Gracieland Studios in Rochdale, UK and Gigantic Studios in New York, NY.Doxanthrine: Doxanthrine is a synthetic compound which is a potent and selective full agonist for the dopamine D1 receptor. Doxanthrine has been shown to be orally active in producing contralateral rotation in the 6-hydroxy-dopamine rat model of Parkinson's disease.HSD2 neurons: HSD2 neurons are a small group of neurons in the brainstem which are uniquely sensitive to the mineralocorticosteroid hormone aldosterone, through expression of HSD11B2. They are located within the caudal medulla oblongata, in the nucleus of the solitary tract (NTS).Vestibular system: The vestibular system, in most mammals, is the sensory system that provides the leading contribution about the sense of balance and spatial orientation for the purpose of coordinating movement with balance. Together with the cochlea, a part of the auditory system, it constitutes the labyrinth of the inner ear in most mammals, situated in the vestibulum in the inner ear (Figure 1).NystagmusAlexander's law: Jacobson GP et al. Alexander's law revisited.Cats in the United States: Many different species of mammal can be classified as cats (felids) in the United States. These include domestic cat (both house cats and feral), of the species Felis catus; medium-sized wild cats from the genus Lynx; and big cats from the genera Puma and Panthera.Mesencephalic nucleus of trigeminal nerve: The mesencephalic nucleus is involved with proprioception of the face, that is, the feeling of position of the muscles. Unlike many nuclei within the central nervous system (CNS), the mesencephalic nucleus contains no chemical synapses but are electrically coupled.SolamargineSturge–Weber syndromeAbducens nucleus: The abducens nucleus is the originating nucleus from which the abducens nerve (VI) emerges - a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the caudal portion of the pons, medial to the sulcus limitans.Oculomotor nucleus: The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle. From this nucleus the fibers pass forward through the tegmentum, the red nucleus, and the medial part of the substantia nigra, forming a series of curves with a lateral convexity, and emerge from the oculomotor sulcus on the medial side of the cerebral peduncle.Vestibulocochlear dysfunction progressive familial: Vestibulocochlear dysfunction progressive familial, known also as familial progressive vestibulocochlear dysfunction is an autosomal dominant disease that results in sensorineural hearing loss and vestibular areflexia. Patients report feelings of vague dissiness, blurred vision, dysequilibrium in the dark, and progressive hearing impairment.Medial lemniscus: The medial lemniscus, also known as Reil's band or Reil's ribbon, is a large ascending bundle of heavily myelinated axons that decussate in the brain stem, specifically in the medulla. The medial lemniscus is formed by the crossings of internal arcuate fibers.Serotonergic cell groups: Serotonergic cell groups refer to collections of neurons in the central nervous system that have been demonstrated by histochemical fluorescence to contain the neurotransmitter serotonin (5-hydroxytryptamine). Since they are for the most part localized to classical brainstem nuclei, particularly the raphe nuclei, they are more often referred to by the names of those nuclei than by the B1-9 nomenclature.XanthohumolVentricular action potentialRostral ventromedial medulla: The rostral ventromedial medulla (RVM), or ventromedial nucleus of the spinal cord, is a group of neurons located close to the midline on the floor of the medulla oblongata (myelencephalon). The rostral ventromedial medulla sends descending inhibitory and excitatory fibers to the dorsal horn spinal cord neurons.Orders of magnitude (acceleration): This page lists examples of the acceleration occurring in various situations. They are grouped by orders of magnitude.Grotto of the RedemptionCortical stimulation mapping: Cortical stimulation mapping (often shortened to CSM) is a type of electrocorticography that involves a physically invasive procedure and aims to localize the function of specific brain regions through direct electrical stimulation of the cerebral cortex. It remains one of the earliest methods of analyzing the brain and has allowed researchers to study the relationship between cortical structure and systemic function.Synaptic gating: Synaptic gating is the ability of neural circuits to gate inputs by either suppressing or facilitating specific synaptic activity. Selective inhibition of certain synapses has been studied thoroughly (see Gate theory of pain), and recent studies have supported the existence of permissively gated synaptic transmission.Dog healthZinc proteinate: Zinc proteinate is the final product resulting from the chelation of zinc with amino acids and/or partially hydrolyzed proteins. It is used as a nutritional animal feed supplement formulated to prevent and/or correct zinc deficiency in animals.Inferior cerebellar peduncle: The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle (restiform body), a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus nerves.Caudal pontine reticular nucleus: The caudal pontine reticular nucleus or nucleus reticularis pontis caudalis is composed of gigantocellular neurons.BetahistineIon transport number: Ion transport number, also called the transference number, is the fraction of the total current carried in an electrolyte by a given ion. Differences in transport number arise from differences in electrical mobility.CiproxifanSolitary nucleus: In the human brain, the solitary nucleus (nucleus of the solitary tract, nucleus solitarius, nucleus tractus solitarii, NTS) is a series of nuclei (clusters of nerve cell bodies) forming a vertical column of grey matter embedded in the medulla oblongata. Through the center of the NTS runs the solitary tract, a white bundle of nerve fibers, including fibers from the facial, glossopharyngeal and vagus nerves, that [the NTS.Qualia: In philosophy, qualia ( or ; singular form: quale) are individual instances of subjective, conscious experience. The term "qualia" derives from the Latin neuter plural form (qualia) of the Latin adjective quālis () meaning "of what sort" or "of what kind").Vertigo (Marvel Comics): Vertigo is a native of the Savage Land who obtained superhuman powers at a young age by genetic engineering. Her powers enable her to render a person severely dizzy and even unconscious.Biotin sulfoxideNeurochondrin: Neurochondrin proteins induces hydroxyapatite resorptive activity in bone marrow cells resistant to bafilomycin A1, an inhibitor of macrophage- and osteoclast-mediated resorption. Expression of the gene is localised to chondrocyte, osteoblast, and osteocyte in the bone and to the hippocampus and Purkinje cell layer of cerebellum in the brain.American Chopper (season 4)Homeostatic plasticity: In neuroscience, homeostatic plasticity refers to the capacity of neurons to regulate their own excitability relative to network activity, a compensatory adjustment that occurs over the timescale of days. Synaptic scaling has been proposed as a potential mechanism of homeostatic plasticity.Hypoglossal trigone: In the upper part of the medulla oblongata, the hypoglossal nucleus approaches the rhomboid fossa, where it lies close to the middle line, under an eminence named the hypoglossal trigone.Cerebral hemisphere: The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the medial longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres.Biotinylated dextran amine: Biotinylated dextran amines (BDA) are organic compounds used as anterograde and retrograde neuroanatomical tracers. They can be used for labeling the source as well as the point of termination of neural connections and therefore to study neural pathways.

(1/260) Eye movement deficits following ibotenic acid lesions of the nucleus prepositus hypoglossi in monkeys II. Pursuit, vestibular, and optokinetic responses.

The eyes are moved by a combination of neural commands that code eye velocity and eye position. The eye position signal is supposed to be derived from velocity-coded command signals by mathematical integration via a single oculomotor neural integrator. For horizontal eye movements, the neural integrator is thought to reside in the rostral nucleus prepositus hypoglossi (nph) and project directly to the abducens nuclei. In a previous study, permanent, serial ibotenic acid lesions of the nph in three rhesus macaques compromised the neural integrator for fixation but saccades were not affected. In the present study, to determine further whether the nph is the neural substrate for a single oculomotor neural integrator, the effects of those lesions on smooth pursuit, the vestibulo-ocular reflex (VOR), vestibular nystagmus (VN), and optokinetic nystagmus (OKN) are documented. The lesions were correlated with long-lasting deficits in eye movements, indicated most clearly by the animals' inability to maintain steady gaze in the dark. However, smooth pursuit and sinusoidal VOR in the dark, like the saccades in the previous study, were affected minimally. The gain of horizontal smooth pursuit (eye movement/target movement) decreased slightly (<25%) and phase lead increased slightly for all frequencies (0.3-1.0 Hz, +/-10 degrees target tracking), most noticeably for higher frequencies (0.8-0.7 and approximately 20 degrees for 1.0-Hz tracking). Vertical smooth pursuit was not affected significantly. Surprisingly, horizontal sinusoidal VOR gain and phase also were not affected significantly. Lesions had complex effects on both VN and OKN. The plateau of per- and postrotatory VN was shortened substantially ( approximately 50%), whereas the initial response and the time constant of decay decreased slightly. The initial OKN response also decreased slightly, and the charging phase was prolonged transiently then recovered to below normal levels like the VN time constant. Maximum steady-state, slow eye velocity of OKN decreased progressively by approximately 30% over the course of the lesions. These results support the previous conclusion that the oculomotor neural integrator is not a single neural entity and that the mathematical integrative function for different oculomotor subsystems is most likely distributed among a number of nuclei. They also show that the nph apparently is not involved in integrating smooth pursuit signals and that lesions of the nph can fractionate the VOR and nystagmic responses to adequate stimuli.  (+info)

(2/260) Effects of viewing distance on the responses of vestibular neurons to combined angular and linear vestibular stimulation.

Effects of viewing distance on the responses of vestibular neurons to combined angular and linear vestibular stimulation. The firing behavior of 59 horizontal canal-related secondary vestibular neurons was studied in alert squirrel monkeys during the combined angular and linear vestibuloocular reflex (CVOR). The CVOR was evoked by positioning the animal's head 20 cm in front of, or behind, the axis of rotation during whole body rotation (0.7, 1.9, and 4.0 Hz). The effect of viewing distance was studied by having the monkeys fixate small targets that were either near (10 cm) or far (1.3-1.7 m) from the eyes. Most units (50/59) were sensitive to eye movements and were monosynaptically activated after electrical stimulation of the vestibular nerve (51/56 tested). The responses of eye movement-related units were significantly affected by viewing distance. The viewing distance-related change in response gain of many eye-head-velocity and burst-position units was comparable with the change in eye movement gain. On the other hand, position-vestibular-pause units were approximately half as sensitive to changes in viewing distance as were eye movements. The sensitivity of units to the linear vestibuloocular reflex (LVOR) was estimated by subtraction of angular vestibuloocular reflex (AVOR)-related responses recorded with the head in the center of the axis of rotation from CVOR responses. During far target viewing, unit sensitivity to linear translation was small, but during near target viewing the firing rate of many units was strongly modulated. The LVOR responses and viewing distance-related LVOR responses of most units were nearly in phase with linear head velocity. The signals generated by secondary vestibular units during voluntary cancellation of the AVOR and CVOR were comparable. However, unit sensitivity to linear translation and angular rotation were not well correlated either during far or near target viewing. Unit LVOR responses were also not well correlated with their sensitivity to smooth pursuit eye movements or their sensitivity to viewing distance during the AVOR. On the other hand there was a significant correlation between static eye position sensitivity and sensitivity to viewing distance. We conclude that secondary horizontal canal-related vestibuloocular pathways are an important part of the premotor neural substrate that produces the LVOR. The otolith sensory signals that appear on these pathways have been spatially and temporally transformed to match the angular eye movement commands required to stabilize images at different distances. We suggest that this transformation may be performed by the circuits related to temporal integration of the LVOR.  (+info)

(3/260) Lesion-induced plasticity in rat vestibular nucleus neurones dependent on glucocorticoid receptor activation.

1. We have recently shown that neurones in the rostral region of the medial vestibular nucleus (MVN) develop a sustained increase in their intrinsic excitability within 4 h of a lesion of the vestibular receptors of the ipsilateral inner ear. This increased excitability may be important in the rapid recovery of resting activity in these neurones during 'vestibular compensation', the behavioural recovery that follows unilateral vestibular deafferentation. In this study we investigated the role of the acute stress that normally accompanies the symptoms of unilateral labyrinthectomy (UL), and in particular the role of glucocorticoid receptors (GRs), in the development of the increase in excitability in the rostral MVN cells after UL in the rat. 2. The compensatory increase in intrinsic excitability (CIE) of MVN neurones failed to occur in animals that were labyrinthectomized under urethane anaesthesia and kept at a stable level of anaesthesia for either 4 or 6 h after UL, so that they did not experience the stress normally associated with the vestibular deafferentation syndrome. In these animals, 'mimicking' the stress response by administration of the synthetic GR agonist dexamethasone at the time of UL, restored and somewhat potentiated CIE in the MVN cells. Administration of dexamethasone in itself had no effect on the intrinsic excitability of MVN cells in sham-operated animals. 3. In animals that awoke after labyrinthectomy, and which therefore experienced the full range of oculomotor and postural symptoms of UL, there was a high level of Fos-like immunoreactivity in the paraventricular nucleus of the hypothalamus over 1.5-3 h post-UL, indicating a strong activation of the stress axis. 4. The GR antagonist RU38486 administered at the time of UL abolished CIE in the rostral MVN cells, and significantly delayed behavioural recovery as indicated by the persistence of circular walking. The mineralocorticoid receptor (MR) antagonist spironolactone administered at the time of UL had no effect. 5. Vestibular compensation thus involves a novel form of 'metaplasticity' in the adult brain, in which the increase in intrinsic excitability of rostral MVN cells and the initial behavioural recovery are dependent both on the vestibular deafferentation and on the activation of glucocorticoid receptors, during the acute behavioural stress response that follows UL. These findings help elucidate the beneficial effects of neuroactive steroids on vestibular plasticity in various species including man, while the lack of such an effect in the guinea-pig may be due to the significant differences in the physiology of the stress axis in that species.  (+info)

(4/260) High-frequency dynamics of regularly discharging canal afferents provide a linear signal for angular vestibuloocular reflexes.

Regularly discharging vestibular-nerve afferents innervating the semicircular canals were recorded extracellularly in anesthetized chinchillas undergoing high-frequency, high-velocity sinusoidal rotations. In the range from 2 to 20 Hz, with peak velocities of 151 degrees/s at 6 Hz and 52 degrees/s at 20 Hz, 67/70 (96%) maintained modulated discharge throughout the sinusoidal stimulus cycle without inhibitory cutoff or excitatory saturation. These afferents showed little harmonic distortion, no dependence of sensitivity on peak amplitude of stimulation, and no measurable half-cycle asymmetry. A transfer function fitting the data predicts no change in sensitivity (gain) of regularly discharging afferents over the frequencies tested but shows a phase lead with regard to head velocity increasing from 0 degrees at 2 Hz to 30 degrees at 20 Hz. These results indicate that regularly discharging afferents provide a plausible signal to drive the angular vestibuloocular reflex (VOR) even during high-frequency head motion but are not a likely source for nonlinearities present in the VOR.  (+info)

(5/260) Activity of smooth pursuit-related neurons in the monkey periarcuate cortex during pursuit and passive whole-body rotation.

Smooth pursuit and vestibularly induced eye movements interact to maintain the accuracy of eye movements in space (i.e., gaze). To understand the role played by the frontal eye fields in pursuit-vestibular interactions, we examined activity of 110 neurons in the periarcuate areas of head-stabilized Japanese monkeys during pursuit eye movements and passive whole-body rotation. The majority (92%) responded with the peak of their modulation near peak stimulus velocity during suppression of the vestibuloocular reflex (VOR) when the monkeys tracked a target that moved with the same amplitude and phase and in the same plane as the chair. We classified pursuit-related neurons (n = 100) as gaze- velocity if their peak modulation occurred for eye (pursuit) and head (VOR suppression) movements in the same direction; the amplitude of modulation during one less than twice that of the other; and modulation was lower during target-stationary-in-space condition (VOR x1) than during VOR suppression. In addition, we examined responses during VOR enhancement (x2) in which the target moved with equal amplitude as, but opposite direction to, the chair. Gaze-velocity neurons responded maximally for opposite directions during VOR x2 and suppression. Based on these criteria, the majority of pursuit-related neurons (66%) were classified as gaze-velocity with preferred directions uniformly distributed. Because the majority of the remaining cells (32/34) also responded during VOR suppression, they were classified as eye/head-velocity neurons. Thirteen preferred pursuit and VOR suppression in the same direction; 13 in the opposite direction, and 6 showed biphasic modulation during VOR suppression. Eye- and gaze-velocity sensitivity of the two groups of cells were similar; mean (+/- SD) was 0.53 +/- 0.30 and 0.50 +/- 0.44 spikes/s per degrees /s, respectively. Gaze-velocity (but not eye/head-velocity) neurons showed significant correlation between eye- and gaze-velocity sensitivity, and both groups maintained their responses when the tracking target was extinguished briefly. The majority of pursuit-related neurons (28/43 = about 65%) responded to chair rotation in complete darkness. When the monkeys fixated a stationary target, more than half of cells tested (21/40) discharged in proportion to the velocity of retinal motion of a second laser spot (mean velocity sensitivity = 0.20 +/- 0.16 spikes/s per degrees /s). Preferred directions of individual cells to the second spot were similar to those during pursuit. Visual responses to the second spot movement were maintained even when it was extinguished briefly. These results indicate that both retinal image- and gaze-velocity signals are carried by single periarcuate pursuit-related neurons, suggesting that these signals can provide target-velocity-in-space and gaze-velocity commands during pursuit-vestibular interactions.  (+info)

(6/260) Rapid compensatory changes in GABA receptor efficacy in rat vestibular neurones after unilateral labyrinthectomy.

1. The inhibitory effects of the GABAA agonist muscimol and the GABAB agonist baclofen on tonically active medial vestibular nucleus (MVN) neurones were recorded in slices of the rat dorsal brainstem in vitro, to determine whether any changes occurred in the functional efficacy of GABAergic inhibition in these cells during the initial rapid stage of 'vestibular compensation', the behavioural recovery that takes place after unilateral labyrinthectomy (UL). These experiments were carried out in preparations where the midline was cut, severing all commissural connections between the two vestibular nuclei. 2. Slices of the MVN were prepared from normal animals and animals that had been unilaterally labyrinthectomised 4 h earlier. The mean in vitro discharge rate of MVN neurones in the rostral region of the ipsi-lesional nucleus after UL was significantly higher than that in control slices, confirming our earlier reports of an increase in intrinsic excitability of these cells in the early stage of vestibular compensation. The in vitro discharge rates of caudal ipsi-lesional MVN cells, and rostral and caudal contra-lesional MVN cells, were not different from controls. 3. Muscimol and baclofen caused reversible, dose-related inhibition of the tonic discharge rate of MVN cells in control slices. In slices prepared from UL animals, MVN cells in the rostral region of the ipsi-lesional nucleus showed a marked downregulation of their response to both muscimol and baclofen, seen as a rightward shift and a decrease in slope of the dose-response relationships for the two agonists. In the contra-lesional nucleus, there was a small but significant upregulation of the responsiveness of both rostral and caudal MVN cells to baclofen, and a marked upregulation of the responsiveness of caudal MVN cells to muscimol. 4. In slices from animals that had undergone bilateral labyrinthectomy 4 h earlier, the downregulation of the functional efficacy of GABA receptors in the rostral MVN cells did not occur. The changes in GABA receptor efficacy after UL are therefore not due to the vestibular de-afferentation itself, but are instead due to the imbalance in excitability of the vestibular nuclei of the lesioned and intact sides, and the enhanced commissural inhibition of the ipsi-lesional MVN cells that follows UL. 5. The downregulation of GABA receptor efficacy in the ipsi-lesional MVN neurones is functionally compensatory, in that their response to commissural and cerebellar inhibitory drive will be significantly reduced after UL. Their intrinsic membrane conductances, and their remaining excitatory synaptic inputs, will consequently be more effective in causing depolarisation and the restoration of resting activity. Simultaneously the upregulation of GABAergic efficacy in the contra-lesional MVN will tend to reduce the hyperactivity on the contralateral side. These adaptive changes therefore represent a plausible cellular mechanism for the recovery of resting discharge in the ipsi-lesional MVN neurones, and the 're-balancing' of the excitability of the vestibular neurones of the lesioned and intact sides, as occurs after UL in vivo. 6. We propose that the adaptive regulation of the functional efficacy of GABA receptors in the MVN neurones may be an important cellular mechanism for the 'homeostasis of bilateral excitability' of the vestibular nuclei of the two sides.  (+info)

(7/260) Convergent properties of vestibular-related brain stem neurons in the gerbil.

Three classes of vestibular-related neurons were found in and near the prepositus and medial vestibular nuclei of alert or decerebrate gerbils, those responding to: horizontal translational motion, horizontal head rotation, or both. Their distribution ratios were 1:2:2, respectively. Many cells responsive to translational motion exhibited spatiotemporal characteristics with both response gain and phase varying as a function of the stimulus vector angle. Rotationally sensitive neurons were distributed as Type I, II, or III responses (sensitive to ipsilateral, contralateral, or both directions, respectively) in the ratios of 4:6:1. Four tested factors shaped the response dynamics of the sampled neurons: canal-otolith convergence, oculomotor-related activity, rotational Type (I or II), and the phase of the maximum response. Type I nonconvergent cells displayed increasing gains with increasing rotational stimulus frequency (0.1-2.0 Hz, 60 degrees /s), whereas Type II neurons with convergent inputs had response gains that markedly decreased with increasing translational stimulus frequency (0.25-2.0 Hz, +/-0.1 g). Type I convergent and Type II nonconvergent neurons exhibited essentially flat gains across the stimulus frequency range. Oculomotor-related activity was noted in 30% of the cells across all functional types, appearing as burst/pause discharge patterns related to the fast phase of nystagmus during head rotation. Oculomotor-related activity was correlated with enhanced dynamic range compared with the same category that had no oculomotor-related response. Finally, responses that were in-phase with head velocity during rotation exhibited greater gains with stimulus frequency increments than neurons with out-of-phase responses. In contrast, for translational motion, neurons out of phase with head acceleration exhibited low-pass characteristics, whereas in-phase neurons did not. Data from decerebrate preparations revealed that although similar response types could be detected, the sampled cells generally had lower background discharge rates, on average one-third lower response gains, and convergent properties that differed from those found in the alert animals. On the basis of the dynamic response of identified cell types, we propose a pair of models in which inhibitory input from vestibular-related neurons converges on oculomotor neurons with excitatory inputs from the vestibular nuclei. Simple signal convergence and combinations of different types of vestibular labyrinth information can enrich the dynamic characteristics of the rotational and translational vestibuloocular responses.  (+info)

(8/260) Cerebral influence on postural effects of cerebellar vermal zonal lesions or eighth nerve section in monkeys.

In monkeys, cerebellar vermal cortical or fastigial nuclear lesion resulted in no significant postural asymmetry. Combined decerebration (but not bulbar pyramid section) and unilateral vermal cortical or fastigial nuclear lesion gave marked ipsilateral hyperextension and contralateral hyperflexion of limbs. Unilateral eighth nerve section resulted in only ipsilateral head tilt but combined unilateral eighth nerve section and decerebration or bilateral or contralateral cerebral cortical areas 4 and 6 lesion gave also ipsilateral flexion and contralateral extension of limbs. Cervical deafferentation or postbrachial spinal cord transection did not alter these results. This study indicates a powerful cerebral influence on postural effects of cerebellar vermal zonal lesion or eighth nerve section in monkeys. Possible mechanisms mediating these effects in monkeys as compared to cats were discussed.  (+info)



cerebellum

  • Some of the axons of the cells of the lateral nucleus, and possibly also of the medial nucleus, are continued upward through the inferior peduncle to the roof nuclei of the opposite side of the cerebellum, to which also other fibers of the vestibular root are prolonged without interruption in the nuclei of the medulla oblongata. (wikipedia.org)
  • The fastigial nucleus is located in the cerebellum. (wikipedia.org)
  • It is one of the four deep cerebellar nuclei (the others being the nucleus dentatus, nucleus emboliformis and nucleus globosus), and is grey matter embedded in the white matter of the cerebellum. (wikipedia.org)
  • The fastigial nucleus sends excitatory projections beyond the cerebellum. (wikipedia.org)
  • At the level of gross anatomy, the cerebellum consists of a tightly folded and crumpled layer of cortex, with white matter underneath, several deep nuclei embedded in the white matter, and a fluid-filled ventricle in the middle. (wikipedia.org)
  • Embedded within the white matter-which is sometimes called the arbor vitae (Tree of Life) in the cerebellum because of its branched, tree-like appearance-are four deep cerebellar nuclei. (wikipedia.org)
  • The four deep nuclei of the cerebellum are the dentate, emboliform, globose, and fastigii nuclei and they act as the main centers of communication, sending and receiving information to and from specific parts of the brain. (wikipedia.org)
  • The lateral vestibular nuclei receive input from cerebellum, particularly the vestibulocerebellum, or the flocculi and nodulus. (wikipedia.org)

neurons

  • In their pioneering effort to test this hypothesis, Edwards and Henkel (1978) described a rostrocaudal gradient of the number of tectal neurons projecting to the region of the abducens nucleus. (jneurosci.org)
  • These are the cortical & brainstem neurons which send motor signals through the pyramidal and extrapyramidal tracts to the cranial and spinal motor nuclei. (slideserve.com)
  • These are the neurons of the motor nuclei of the cranial nerves and anterior motor neurons in the spinal cord, their axons, and the muscles innervated by them. (slideserve.com)
  • APN in OPT may result from electrotonic coupling between neurons in the hypertrophied inferior olivary nucleus, which induces maladaptive learning in cerebellar cortex. (pubmedcentralcanada.ca)
  • Like other descending motor pathways, the vestibulospinal fibers of the tract relay information from nuclei to motor neurons. (wikipedia.org)
  • When the vestibular sensory neurons detect small movements of the body, the vestibulospinal tract commands motor signals to specific muscles to counteract these movements and re-stabilize the body. (wikipedia.org)
  • The soma (cell bodies) in these nuclei are the second-order neurons of the posterior column-medial lemniscus pathway, and their axons, called the internal arcuate fibers or fasciculi, decussate from one side of the medulla to the other to form the medial lemniscus. (wikipedia.org)
  • Saccade-related neurons in the primate fastigial nucleus: what do they encode? (wikipedia.org)

medulla

  • The fibers of the vestibular nerve enter the medulla oblongata on the medial side of those of the cochlear, and pass between the inferior peduncle and the spinal tract of the trigeminal nerve. (wikipedia.org)
  • Lateral vestibulo-spinal tract (lateral vestibular nucleus "Deiters")- via ventrolateral medulla and spinal cord to ventral funiculus (lumbo-sacral segments). (wikipedia.org)
  • Neuroblasts from the alar plate of the neural tube at this level will produce the sensory nuclei of the medulla. (wikipedia.org)
  • Most of its efferent connections travel via the inferior cerebellar peduncle to the vestibular nuclei, which are located at the junction of the pons and the medulla oblongata. (wikipedia.org)
  • Pain and temperature information is also not represented within the principle nucleus, but rather in the spinal trigeminal nucleus, which is caudal to the pontine tegmentum in the medulla. (wikipedia.org)
  • The facial solitary nucleus, which carries taste information from the anterior 2/3 of the tongue, is located caudal to the pontine tegmentum in the medulla. (wikipedia.org)
  • The remaining nuclei are located within the medulla. (wikipedia.org)
  • The two divisions of the cochlear nucleus, which process auditory input from the cochlea, lie on the border of the pons and the medulla. (wikipedia.org)

fibers

  • The ascending fibers either end in the same manner or in the lateral nucleus, which is situated lateral to the area acustica and farther from the ventricular floor. (wikipedia.org)
  • Deiter's nucleus) has descending efferent fibers in the vestibulocochlear nerve distributed to the motor nuclei of the anterior column and exerts an excitatory influence on ipsilateral limb extensor motoneurons while suppressing flexor motoneurons. (wikipedia.org)
  • stria medullaris" - fibers derived from arcuate nuclei, which emerge from the median sulcus and run transversely across the floor to enter into the inferior cerebellar peduncle. (wikipedia.org)
  • The gray matter of this nucleus is covered by a layer of nerve fibers that form the spinal tract of the trigeminal nerve. (wikipedia.org)
  • Direct branches of the vertebral artery: The vertebral artery supplies an area between the other two main arteries, including the solitary nucleus and other sensory nuclei and fibers. (wikipedia.org)
  • Alar plate neuroblasts give rise to: The solitary nucleus, which contains the general visceral afferent fibers for taste, as well as the special visceral afferent column. (wikipedia.org)
  • The lateral part of the vestibulospinal tract is the major portion and is composed of fibers originating in the lateral, superior, and inferior vestibular nuclei (primarily the lateral). (wikipedia.org)

deep nuclei

  • The conditioning-specific increase in Purkinje cell dendritic excitability produces an afterhyperpolarization, which is hypothesized to release the cerebellar deep nuclei from inhibition, allowing conditioned responses to be elicited via the red nucleus and accessory abducens motorneurons. (jneurosci.org)
  • The function of the cerebellar cortex is essentially to modulate information flowing through the deep nuclei. (wikipedia.org)

input from the vestibular

  • Vestibular cortex is the portion of the cerebrum which responds to input from the vestibular system. (wikipedia.org)
  • It receives input from the vestibular nuclei and contributes to vestibular neuronal activity. (wikipedia.org)

cerebellar

  • The Purkinje cells of the cerebellar cortex project into the deep cerebellar nuclei and inhibit the excitatory output system via GABAergic synapses. (wikipedia.org)

pedunculopontine tegment

  • ChAT-immunoreactive (ChAT-IR) cells comprise several prominent groups, including the pedunculopontine tegmental nucleus, laterodorsal tegmental nucleus, and parabigeminal nucleus, as well as the cranial nerve somatic motor and parasympathetic nuclei. (pubmedcentralcanada.ca)
  • Three nuclei, the pedunculopontine tegmental nucleus (PPT), laterodorsal tegmental nucleus (LDT), and parabigeminal nucleus (PBG), are traditionally identified as the main sources of cholinergic projections to other brainstem nuclei and to the thalamus. (pubmedcentralcanada.ca)

medial nucleus

  • The latter end by arborizing around the cells of the medial nucleus, which is situated in the area acustica of the rhomboid fossa. (wikipedia.org)

pons

  • The lateral vestibulospinal tract originates in the lateral vestibular nucleus or Deiters' nucleus in the pons. (wikipedia.org)
  • The Deiters' nucleus extends from pontomedullary junction to the level of abducens nerve nucleus in the pons. (wikipedia.org)
  • Nearby important structures include the cranial nerve nuclei of the oculomotor (3rd) and trochlear (4th) nerve nuclei, which are located in the midbrain, the pontine nuclei, which are located within the basilar pons, and the raphe nucleus and the locus ceruleus, nuclei of cranial nerves 9-12, and the dorsal respiratory group, which are located further caudally in the brainstem. (wikipedia.org)
  • The superior vestibular nucleus, one of four vestibular nuclei, is located within the pons. (wikipedia.org)

fourth ventricle

  • The inferior vestibular nucleus is the vestibular nucleus which lies near the fourth ventricle. (wikipedia.org)
  • The fastigium, (Latin for summit), is used to refer to the peak of the fourth ventricle.The fastigial nucleus lies immediately above the roof of the fourth ventricle. (wikipedia.org)

cortical

  • Sensitivity of human visual and vestibular cortical regions to egomotion-compatible visual stimulation. (springer.com)

oculomotor

  • A second set of fibres from the medial and lateral nuclei end partly in the tegmentum, while the remainder ascend in the medial longitudinal fasciculus to arborize around the cells of the nuclei of the oculomotor nerve. (wikipedia.org)
  • Thus, with the exception of voluntary eye movements, the vestibular and oculomotor systems are thoroughly linked. (wikipedia.org)

abducens nucleus

  • The abducens nucleus controls abduction (outward rotation) of the eye. (wikipedia.org)

brainstem

  • A few studies have identified cholinergic effects in other brainstem auditory nuclei, such as the inferior colliculus (e.g. (pubmedcentralcanada.ca)
  • Vestibular stimuli activate primitive reflexes in human infants, such as the asymmetric tonic neck reflex, Moro reflex, and parachute reflexes, which are likely mediated by vestibular nuclei in the brainstem. (wikipedia.org)

cholinergic nuclei

  • This in turn requires a detailed description of cholinergic nuclei in the species under study. (pubmedcentralcanada.ca)
  • The pontine tegmentum contains two predominately cholinergic nuclei, the pedunculopontine nucleus (PPN) and the laterodorsal tegmental nucleus, which project widely throughout the brain. (wikipedia.org)

nerve

  • 5) In cat studies involving measurements of the field potential of the lateral vestibular nucleus , the application of acetylcholine produces the same response as does stimulation of the vestibular nerve. (thefreedictionary.com)
  • The vestibular nuclei are the cranial nuclei for the vestibular nerve. (wikipedia.org)
  • Vestibular nerve Vestibulocerebellar syndrome Deep dissection of brain-stem. (wikipedia.org)
  • Bilaterally for head/neck/eye movements It is one of the nuclei that corresponds to CN VIII, corresponding to the vestibular nerve, which joins with the cochlear nerve. (wikipedia.org)
  • The superior vestibular nucleus (Bechterew's nucleus) is the dorso-lateral part of the vestibular nucleus and receives collaterals and terminals from the ascending branches of the vestibular nerve. (wikipedia.org)
  • The lateral vestibular nucleus (Deiters's nucleus) is the continuation upward and lateralward of the principal nucleus, and in it terminate many of the ascending branches of the vestibular nerve. (wikipedia.org)
  • The vestibular nuclei receive information through the vestibulocochlear nerve about changes in the orientation of the head. (wikipedia.org)
  • This is seen in anterior (ventral) horn cells or certain cranial nerve nuclei. (wikipedia.org)
  • this reaction creates an action potential carried by the vestibular nerve. (wikipedia.org)
  • If stereocilia go towards kinocilium depolarization occurs causing more neurotransmitter, and more vestibular nerve firings as compared to when stereocilia tilt away from kinocilium (hyperpolarization, less neurotransmitter, less firing). (wikipedia.org)
  • The vestibular system, which sends information to the brain via cranial nerve VIII (vestibulocochlear nerve), plays a major role in motion sickness, and is rich in muscarinic receptors and histamine H1 receptors. (wikipedia.org)
  • The spinal trigeminal nerve nuclei which contains the general somatic afferent column. (wikipedia.org)
  • The pontine tegmentum contains nuclei of the cranial nerves (trigeminal (5th), abducens (6th), facial (7th), and vestibulocochlear (8th) cranial nerve nuclei) and their associated fibre tracts, the tegmental pontine reticular nucleus, the mesopontine cholinergic system comprising the pedunculopontine nucleus and the laterodorsal tegmental nucleus, and the respiratory centres - the pneumotaxic centre and the apneustic centre. (wikipedia.org)
  • The principal sensory nucleus of the trigeminal nerve represents touch and position information of the head and face, but not the neck or back of the head, which are innervated by the cervical nerves. (wikipedia.org)
  • The facial motor nucleus and the superior salivary nucleus of the facial nerve are located within the pontine tegmentum. (wikipedia.org)

trigeminal

  • Organisation of reciprocal connections between trigeminal and vestibular nuclei in the rat. (springer.com)
  • It is caused by an underlying collection of gray matter known as the spinal trigeminal nucleus. (wikipedia.org)

olivary nuclei

  • They are caused by the largest nuclei of the olivary bodies, the inferior olivary nuclei. (wikipedia.org)

human vestibular

  • The B_r_ny Society is named after Prof. Dr. Robert B_r_ny who clarifie d the physiology and pathology of the human vestibular apparatus and w as awarded the Nobel Prize for his work in 1914. (ecampus.com)

sensory

  • The vestibular system is able to respond correctly by recording sensory information from hairs cells in the labyrinth of the inner ear. (wikipedia.org)
  • Thanks to the number of different nuclei located within the pontine tegmentum, it is a region associated with a range of functions including sensory and motor functions (due to the cranial nuclei and fiber tracts), control of stages of sleep and levels of arousal and vigilance (due to the ascending cholinergic systems), and some aspects of respiratory control. (wikipedia.org)
  • The pontine tegmentum contains nuclei of several cranial nerves and consequently has a role in several groups of sensory and motor processes. (wikipedia.org)

cortex

  • according to Cajal they merely pass through the nucleus fastigii on their way to the cortex of the vermis and the hemisphere. (wikipedia.org)
  • Then the nuclei receiving these signals project out to the extraocular muscles, spinal cord, and cerebral cortex to execute these functions. (wikipedia.org)
  • The "temporo-peri-Sylvian vestibular cortex" (TPSVC) has been proposed as an analog to parietoinsular vestibular cortex found in monkeys. (wikipedia.org)

tracts

  • A more appropriate classification of motor nuclei and tracts would be by their functions. (wikipedia.org)

Superior Colliculus

  • Additional concentrations are present in the parabrachial nuclei and superior colliculus. (pubmedcentralcanada.ca)

semicircular canals

  • There are three critical aspects to the theory: first is the close linkage between activity in the vestibular system, i.e., semicircular canals and otolith organs, and a change in tonus among various of each eye's six extra-ocular muscles. (wikipedia.org)
  • The vestibular system, the region of the inner ear where three semicircular canals converge, works with the visual system to keep objects in focus when the head is moving. (wikipedia.org)

dorsal

cochlear nucleus

  • A few ChAT-IR cells are found in the cochlear nucleus and the ventral nucleus of the lateral lemniscus. (pubmedcentralcanada.ca)

fastigial nucleus

  • Although it is one dense mass, it is made up of two sections: the rostral fastigial nucleus and the caudal fastigial nucleus. (wikipedia.org)
  • The fastigial nucleus receives its input from Purkinje cells in the vermis. (wikipedia.org)
  • The likely neurotransmitters of fastigial nucleus axons are glutamate and aspartate. (wikipedia.org)
  • The rostral fastigial nucleus (rFN) is related to the vestibular system. (wikipedia.org)
  • The caudal fastigial nucleus (cFN) is related to saccadic eye movements. (wikipedia.org)

vestibulospinal tract

  • Fibres from the lateral vestibular nucleus also pass via the vestibulospinal tract, to anterior horn cells at many levels in the spinal cord, in order to co-ordinate head and trunk movements. (wikipedia.org)
  • The nuclei relay motor commands through the vestibulospinal tract. (wikipedia.org)
  • The vestibulospinal tract is part of the vestibular system in the CNS. (wikipedia.org)
  • The vestibulospinal tract is an upper motor neuron tract consisting of two sub-pathways: The medial vestibulospinal tract projects bilaterally from the medial vestibular nucleus within the medial longitudinal fasciculus to the ventral horns in the upper cervical cord (C6 vertebra). (wikipedia.org)

Deiters

  • Deiter's nucleus was named after German neuroanatomist Otto Friedrich Karl Deiters (1834-1863). (wikipedia.org)

anterior

  • the descending branches pass down in the posterior longitudinal bundle into the anterior funiculus of the spinal cord as the vestibulospinal fasciculus (anterior marginal bundle) and are distributed to motor nuclei of the anterior column by terminals and collaterals. (wikipedia.org)

ventral

  • Among auditory nuclei, the majority of ChAT-IR cells are in the superior olive, particularly in and around the lateral superior olive, the ventral nucleus of the trapezoid body and the superior paraolivary nucleus. (pubmedcentralcanada.ca)

stimulation

  • 2003). Use of electrical vestibular stimulation to alter genioglossal muscle activity in awake cats. (springer.com)
  • An alternative theory, also known as the Nystagmus Hypothesis, has been proposed based on stimulation of the vagus nerves resulting from the stretching or traction of extra-ocular muscles co-occurring with eye movements caused by vestibular stimulation. (wikipedia.org)

neural

  • 11 - 13 Therefore, these drugs can indirectly depolarize the cells of the nucleus prepositus hypoglossi (and thereby make the neural integrator less unstable) and reduce the amplitude of APN in patients with MS. We also hypothesize that baclofen, a GABAergic drug that hyperpolarizes the cell membrane, may not reduce the amplitude of APN and may even increase it. (pubmedcentralcanada.ca)

parasympathetic

  • The facial motor nucleus serve motor control of the muscles of facial expression and the stapedius muscle of the ear, while the superior salivary nucleus controls the secretion of saliva and tears through parasympathetic innervation of structures including the lacrimal gland and the mucosal glands of the nose, palate, and pharynx. (wikipedia.org)

system

  • In The Vestibular System: A Sixth Sense , leading experts present an integrative, comprehensive and innovative look at the sense that Aristotle missed. (oup.com)
  • The vestibular system plays a vital role in everyday life, contributing to a surprising range of functions from reflexes to the highest levels of perception and consciousness. (oup.com)
  • Dynamic, intellectually challenging, and unique in its level of integration of the material, this book is essential for anyone interested in understanding the vestibular system. (oup.com)
  • The primary role of the vestibular system is to maintain head and eye coordination, upright posture and balance, and conscious realization of spatial orientation and motion. (wikipedia.org)
  • In these cases, motion is sensed by the vestibular system and hence the motion is felt, but no motion or little motion is detected by the visual system. (wikipedia.org)
  • Balance is the result of a number of body systems working together: the eyes (visual system), ears (vestibular system) and the body's sense of where it is in space (proprioception) ideally need to be intact. (wikipedia.org)
  • In the vestibular system, equilibrioception is determined by the level of a fluid called endolymph in the labyrinth, a complex set of tubing in the inner ear. (wikipedia.org)

brain

  • Visual signals sent to the brain about the body's position in relation to its surroundings are processed by the brain and compared to information from the vestibular, visual and skeletal systems. (wikipedia.org)
  • In addition, these nuclei receive both inhibitory and excitatory signals from other parts of the brain which in turn affect the nuclei's outgoing signals. (wikipedia.org)

Rostral

  • The rostral interstitial nucleus of medial longitudinal fasciculus (riMLF) is a portion of the medial longitudinal fasciculus which controls vertical gaze. (wikipedia.org)