DOCSLIB.ORG

A Note on Species Differences Among Primates

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Note on Species Differences Among Primates J. Neurosurg. / Volume 31 / August, 1969 The Postural Effect of Lesions of the Vestibular Nuclei: A Note on Species Differences Among Primates EDWARD TARLOV, M.D.* Surgical Neurology Branch, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Public Health Service, Department of Health, Education and Welfare, Bethesda, Maryland HE pathology of human spasmodic and, in some cases, the Fink-Heimer silver torticollis 1,12,14,15,~3 has not been con- stains for degenerated axons were used on T vincingly demonstrated and therefore adjacent series. The sections stained for cells the recent papers 13,16 on abnormalities of head were projected onto Kodak photomechanical posture resulting from experimental lesions T paper and photographed. Nuclear bounda- in the brain stem have evoked considerable ries and destruction of tissue by the lesion interest. Lately I have had an opportunity were drawn directly onto these photographs, during the course of a study of the primate and reconstructions of the brain stem and central vestibular connections 24 to observe the extent of the lesion were made from 10 Macaques, a baboon, and a chimpanzee tracings of these photographs. A detailed de- with experimental lesions of the vestibular scription of each of these lesions, the extent nuclei. Lesions of similar extent produced of damage, however slight, to surrounding strikingly different postural effects in the regions, and the rostral projections of degen- species examined. The data indicate that le- erated fibers is given elsewhereY 4 sions in the central nervous system that are The terminology used to describe the ves- responsible for abnormalities of posture in tibular nuclei is that of Brodal and monkeys may have quite different effects on PompeianoY In addition to the four classical the posture of the higher primates. vestibular nuclei (the superior vestibular nu- cleus of von Bechterew, the medial vestibu- Materials and Methods lar nucleus of Schwalbe, the lateral vestibu- Ten immature and adult Rhesus Ma- lar nucleus of Deiters, and the spinal vestib- caques (Macaca mulatta), a large male ba- ular nucleus), two other regions are indi- boon (Theropithecus gelada), and an imma- cated in Figs. 1 to 4. These are the intersti- ture female chimpanzee (Pan troglodytes E. tial nucleus of the vestibular nerve, whose P. Walker) were studied. None of the ani- cells lie interspersed among the fibers of the mals had been previously used in any other vestibular nerve, and the area x, a small studies or operations. group of cells lying between the caudal tip of Lesions in the right lateral floor of the the spinal vestibular nucleus and the lateral fourth ventricle were placed with a fine cuneate nucleus. The abbreviations for the curved glass suction pipet under direct vi- terminology are given below. sion, after elevation of the cerebellar vermis A.pt. area postrema through a suboccipital craniectomy. The ani- Am. nucleus ambiguus mals were deeply anesthetized and sacrificed B.cj. brachium conjunctivum by perfusion following postoperative survival C.r. restiform body times of between 6 and 16 days. Longer sur- Cu.L. lateral cuneate nucleus vivals interfered with optimal selective silver Cu.m. medial cuneate nucleus staining of degenerated axons. D.mo.X dorsal motor nucleus of the vagus After fixation, frozen sections were cut at F.L.m. medial longitudinal fasciculus 25 to 30 7 in frontal, sagittal, or horizontal G. gracile nucleus planes. Serial sections every 450 to 500 p. G.L. lateral geniculate body N.po. pontine nuclei were stained with cresyl violet or luxol fast N.t.s. nucleus of the tractus solitarius blue and cresyl violet. The Nauta-Gygax N.Vme. mesencephalic nucleus of the tri- Received for publication July 26, 1968. geminal nerve * Present address: Neurosurgical Service, Massa- N.Vmo. motor nucleus of the trigeminal chusetts General Hospital, Boston, Massachusetts. nerve 187 188 Edward Tarlov Fro. 1. Sections showing extent of lesions involving vestibular complex. Comparable lesions that pro- duced severe postural abnormality in Macaques were associated with only slight postural disturbance in the baboon and even less in the chimpanzee. A. Macaque V-2. Frontal sections progressing from caudal to rostral. Lesion involved right spinal, medial, lateral, and superior vestibular nuclei and injured superior cerebellar peduncle and posterior column nuclei. Animal had severe cephalic and trunk torsion (see Fig. 5 left), B. Macaque V-3. Sagittal section; left side is rostral. Lesion involved medial and spinal vestibular nuclei. The animal's marked postural abnormality was similar to that of Macaque V-2. C. Baboon V-1-67. Sagittal section; left side is rostral. Lesion involved right superior, medial, lateral, and spinal vestibular nuclei. Animal had only slight postural disturbance, with ipsilateral in- clination of its head. D. Chimpanzee C-1-67. Sagittal section; right side is rostral. Lesion of superior, medial, lateral, and spinal vestibular nuclei, also damaged superior cerebellar peduncle. The animal demonstrated only very slight and transient postural disorder which lasted 3 days (see Fig. 5 right). N.Vs. principal sensory nucleus of the Ve.L. lateral vestibular nucleus (Deiters) trigeminal nerve Ve.m. medial vestibular nucleus Ne.IV trochlear nerve (Schwalbe) Ne.VII facial nerve Ve.s. superior vestibular nucleus O.i. inferior olive (Bechterew) Ru. red nucleus Ve.sp. spinal vestibular nucleus S.n. substantia nigra Ve.in. interstitial nucleus of the vestibular T.O. optic tract nerve .
Load more

Recommended publications
  • Optogenetic Fmri Interrogation of Brain-Wide Central Vestibular Pathways
    Optogenetic fMRI interrogation of brain-wide central vestibular pathways Alex T. L. Leonga,b, Yong Guc, Ying-Shing Chand, Hairong Zhenge, Celia M. Donga,b, Russell W. Chana,b, Xunda Wanga,b, Yilong Liua,b, Li Hai Tanf, and Ed X. Wua,b,d,g,1 aLaboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; bDepartment of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; cInstitute of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; dSchool of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; eShenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; fCenter for Language and Brain, Shenzhen Institute of Neuroscience, Shenzhen 518057, China; and gState Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China Edited by Marcus E. Raichle, Washington University in St. Louis, St. Louis, MO, and approved March 20, 2019 (received for review July 20, 2018) Blood oxygen level-dependent functional MRI (fMRI) constitutes a multisensory integration process in the vestibular system is op- powerful neuroimaging technology to map brain-wide functions tokinetic nystagmus, whereby visual cues are used to induce in response to specific sensory or cognitive tasks. However, fMRI compensatory reflexive eye movements to maintain a stable gaze mapping of the vestibular system, which is pivotal for our sense of while moving (11, 12). These eye movements involve inputs from balance, poses significant challenges.
    [Show full text]
  • Pharnygeal Arch Set - Motor USMLE, Limited Edition > Neuroscience > Neuroscience
    CNs 5, 7, 9, 10 - Pharnygeal Arch Set - Motor USMLE, Limited Edition > Neuroscience > Neuroscience PHARYNGEAL ARCH SET, CNS 5, 7, 9, 10 • They are derived from the pharyngeal (aka branchial) arches • They have special motor and autonomic motor functions CRANIAL NERVES EXIT FROM THE BRAINSTEM CN 5, the trigeminal nerve exits the mid/lower pons.* CN 7, the facial nerve exits the pontomedullary junction.* CN 9, the glossopharyngeal nerve exits the lateral medulla.* CN 10, the vagus nerve exits the lateral medulla.* CRANIAL NERVE NUCLEI AT BRAINSTEM LEVELS Midbrain • The motor trigeminal nucleus of CN 5. Nerve Path: • The motor division of the trigeminal nerve passes laterally to enter cerebellopontine angle cistern. Pons • The facial nucleus of CN 7. • The superior salivatory nucleus of CN 7. Nerve Path: • CN 7 sweeps over the abducens nucleus as it exits the brainstem laterally in an internal genu, which generates a small bump in the floor of the fourth ventricle: the facial colliculus • Fibers emanate from the superior salivatory nucleus, as well. Medulla • The dorsal motor nucleus of the vagus, CN 10 • The inferior salivatory nucleus, CN 9 1 / 3 • The nucleus ambiguus, CNs 9 and 10. Nerve Paths: • CNs 9 and 10 exit the medulla laterally through the post-olivary sulcus to enter the cerebellomedullary cistern. THE TRIGEMINAL NERVE, CN 5  • The motor division of the trigeminal nerve innervates the muscles of mastication • It passes ventrolaterally through the cerebellopontine angle cistern and exits through foramen ovale as part of the mandibular division (CN 5[3]). Clinical Correlation - Trigeminal Neuropathy THE FACIAL NERVE, CN 7  • The facial nucleus innervates the muscles of facial expression • It spans from the lower pons to the pontomedullary junction.
    [Show full text]
  • Direct Projections from Cochlear Nuclear Complex to Auditory Thalamus in the Rat
    The Journal of Neuroscience, December 15, 2002, 22(24):10891–10897 Direct Projections from Cochlear Nuclear Complex to Auditory Thalamus in the Rat Manuel S. Malmierca,1 Miguel A. Mercha´n,1 Craig K. Henkel,2 and Douglas L. Oliver3 1Laboratory for the Neurobiology of Hearing, Institute for Neuroscience of Castilla y Leo´ n and Faculty of Medicine, University of Salamanca, 37007 Salamanca, Spain, 2Wake Forest University School of Medicine, Department of Neurobiology and Anatomy, Winston-Salem, North Carolina 27157-1010, and 3University of Connecticut Health Center, Department of Neuroscience, Farmington, Connecticut 06030-3401 It is known that the dorsal cochlear nucleus and medial genic- inferior colliculus and are widely distributed within the medial ulate body in the auditory system receive significant inputs from division of the medial geniculate, suggesting that the projection somatosensory and visual–motor sources, but the purpose of is not topographic. As a nonlemniscal auditory pathway that such inputs is not totally understood. Moreover, a direct con- parallels the conventional auditory lemniscal pathway, its func- nection of these structures has not been demonstrated, be- tions may be distinct from the perception of sound. Because cause it is generally accepted that the inferior colliculus is an this pathway links the parts of the auditory system with prom- obligatory relay for all ascending input. In the present study, we inent nonauditory, multimodal inputs, it may form a neural have used auditory neurophysiology, double labeling with an- network through which nonauditory sensory and visual–motor terograde tracers, and retrograde tracers to investigate the systems may modulate auditory information processing.
    [Show full text]
  • Auditory and Vestibular Systems Objective • to Learn the Functional
    Auditory and Vestibular Systems Objective • To learn the functional organization of the auditory and vestibular systems • To understand how one can use changes in auditory function following injury to localize the site of a lesion • To begin to learn the vestibular pathways, as a prelude to studying motor pathways controlling balance in a later lab. Ch 7 Key Figs: 7-1; 7-2; 7-4; 7-5 Clinical Case #2 Hearing loss and dizziness; CC4-1 Self evaluation • Be able to identify all structures listed in key terms and describe briefly their principal functions • Use neuroanatomy on the web to test your understanding ************************************************************************************** List of media F-5 Vestibular efferent connections The first order neurons of the vestibular system are bipolar cells whose cell bodies are located in the vestibular ganglion in the internal ear (NTA Fig. 7-3). The distal processes of these cells contact the receptor hair cells located within the ampulae of the semicircular canals and the utricle and saccule. The central processes of the bipolar cells constitute the vestibular portion of the vestibulocochlear (VIIIth cranial) nerve. Most of these primary vestibular afferents enter the ipsilateral brain stem inferior to the inferior cerebellar peduncle to terminate in the vestibular nuclear complex, which is located in the medulla and caudal pons. The vestibular nuclear complex (NTA Figs, 7-2, 7-3), which lies in the floor of the fourth ventricle, contains four nuclei: 1) the superior vestibular nucleus; 2) the inferior vestibular nucleus; 3) the lateral vestibular nucleus; and 4) the medial vestibular nucleus. Vestibular nuclei give rise to secondary fibers that project to the cerebellum, certain motor cranial nerve nuclei, the reticular formation, all spinal levels, and the thalamus.
    [Show full text]
  • Use of Calcium-Binding Proteins to Map Inputs in Vestibular Nuclei of the Gerbil
    THE JOURNAL OF COMPARATIVE NEUROLOGY 386:317–327 (1997) Use of Calcium-Binding Proteins to Map Inputs in Vestibular Nuclei of the Gerbil GOLDA ANNE KEVETTER* AND ROBERT B. LEONARD Departments of Otolaryngology, Anatomy and Neurosciences, and Physiology and Biophysics, University of Texas Medical Branch, Galveston, Texas 77555 ABSTRACT We wished to determine whether calbindin and/or calretinin are appropriate markers for vestibular afferents, a population of neurons in the vestibular nuclear complex, or cerebellar Purkinje inputs. To accomplish this goal, immunocytochemical staining was observed in gerbils after lesions of the vestibular nerve central to the ganglion, the cerebellum, or both. Eleven to fourteen days after recovery, the brain was processed for immunocytochemical identification of calretinin and calbindin. After lesion of the vestibular nerve, no calretinin staining was seen in any of the vestibular nuclei except for a population of intrinsic neurons, which showed no obvious change in number or staining pattern. Calbindin staining was reduced in all nuclei except the dorsal part of the lateral vestibular nuclei. The density of staining of each marker, measured in the magnocellular medial vestibular nucleus, was signifi- cantly reduced. After the cerebellar lesion, no differences in calretinin staining were noted. However, calbindin staining was greatly reduced in all nuclei. The density of staining, measured in the caudal medial vestibular nucleus, was significantly lower. After a combined lesion of the cerebellum and vestibular nerve, the distribution and density of calretinin staining resembled that after vestibular nerve section alone, whereas calbindin staining was no longer seen. This study demonstrates that calretinin and calbindin are effective markers for the identification of vestibular afferents.
    [Show full text]
  • Introduction
    Journal ofVestibularResearcn, VoL 1, 1~u. L, PP·,, ~~, -- _ Copyright © 1997 Elsevier Science Inc. Printed in the USA. All rights reserved 0957-4271/97 $17.00 + .00 Pll 80957-4271(96)00137-1 Original Contribution AGING AND THE HUMAN VESTIBULAR NUCLEUS Ivan Lopez,* Vicente Honrubia,* and Robert W. Baloh,*t UCLA School of Medicine, *Division of Head and Neck Surgery, tDepartment of Neurology, Los Angeles, California Reprint address: Robert W. Baloh, M.D., Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90024-1769; Tel: (310) 825-5910; Fax: (310) 206-1513 0 Abstract-Degenerative changes during aging Introduction have been identified in the inner ear and in the vestibular nerve, but not in the human vestibular Complaints of dizziness and disequilibrium are nuclear complex (VNC). Therefore, the purpose of extremely common in older people (1). Associ­ this study was to document quantitative morpho­ ated falls are a major cause of morbidity and mor­ metric changes within the VNC in humans as a function of age. The VN C of normal human sub­ tality (2,3). Age-related morphological changes jects was examined for age-related changes using occur in all of the sensory systems essential for computer-based microscopy. Neuronal counts, nu­ maintaining balance during locomotion. Neu­ clear volume, neuronal density, and nuclear roanatomical studies of the peripheral vestibular length of the 4 vestibular nuclei were determined system have documented a significant loss of in 15 normal people, age 40 to 93 years. Based on a hair cells and primary vestibular neurons as a linear model, there was approximately a 3% neu­ function of age (4,5).
    [Show full text]
  • Probing Forebrain to Hindbrain Circuit Functions in Xenopus
    Received: 15 November 2016 | Accepted: 16 November 2016 DOI 10.1002/dvg.22999 REVIEW Probing forebrain to hindbrain circuit functions in Xenopus Darcy B. Kelley1 | Taffeta M. Elliott2 | Ben J. Evans3 | Ian C. Hall4 | Elizabeth C. Leininger5 | Heather J. Rhodes6 | Ayako Yamaguchi7 | Erik Zornik8 1Department of Biological Sciences, Columbia University, New York, New York Abstract 10027 The vertebrate hindbrain includes neural circuits that govern essential functions including breath- 2Department of Psychology, New Mexico ing, blood pressure and heart rate. Hindbrain circuits also participate in generating rhythmic motor Tech, Socorro, New Mexico 87801 patterns for vocalization. In most tetrapods, sound production is powered by expiration and the 3 Department of Biology, McMaster circuitry underlying vocalization and respiration must be linked. Perception and arousal are also University, Hamilton, Ontario, Ontario linked; acoustic features of social communication sounds—for example, a baby’scry—can drive L8S4K1, Canada autonomic responses. The close links between autonomic functions that are essential for life and 4Department of Biology, Benedictine University, Lisle, Illinois vocal expression have been a major in vivo experimental challenge. Xenopus provides an opportu- 5Department of Biology, St. Mary’s College, nity to address this challenge using an ex vivo preparation: an isolated brain that generates vocal St. Mary’s City, Maryland 29686 and breathing patterns. The isolated brain allows identification and manipulation of hindbrain vocal 6Department of Biology, Denison University, circuits as well as their activation by forebrain circuits that receive sensory input, initiate motor Granville, Ohio 43023 patterns and control arousal. Advances in imaging technologies, coupled to the production of Xen- 7 Department of Biology, University of Utah, opus lines expressing genetically encoded calcium sensors, provide powerful tools for imaging Salt Lake City, Utah 84112 neuronal patterns in the entire fictively behaving brain, a goal of the BRAIN Initiative.
    [Show full text]
  • Vestibular Blueprint in Early Vertebrates
    REVIEW ARTICLE published: 19 November 2013 doi: 10.3389/fncir.2013.00182 Vestibular blueprint in early vertebrates Hans Straka 1* and Robert Baker 2 1 Department Biology II, Ludwig-Maximilians-Universität München, Planegg, Germany 2 Department of Neuroscience and Physiology, Langone Medical Center, New York University, New York, NY, USA Edited by: Central vestibular neurons form identifiable subgroups within the boundaries of classically Catherine Carr, University of outlined octavolateral nuclei in primitive vertebrates that are distinct from those processing Maryland, USA lateral line, electrosensory, and auditory signals. Each vestibular subgroup exhibits Reviewed by: a particular morpho-physiological property that receives origin-specific sensory inputs Leonard Maler, University of Ottawa, Canada from semicircular canal and otolith organs. Behaviorally characterized phenotypes send Joel C. Glover, University of Oslo, discrete axonal projections to extraocular, spinal, and cerebellar targets including other Norway ipsi- and contralateral vestibular nuclei. The anatomical locations of vestibuloocular and *Correspondence: vestibulospinal neurons correlate with genetically defined hindbrain compartments that are Hans Straka, Department Biology II, well conserved throughout vertebrate evolution though some variability exists in fossil and Ludwig-Maximilians-Universität München, Grosshadernerstr. 2, 82152 extant vertebrate species.The different vestibular subgroups exhibit a robust sensorimotor Planegg, Germany signal processing complemented
    [Show full text]
  • Adrenergic Activation of Cardiac Preganglionic Neurons in Nucleus
    bioRxiv preprint doi: https://doi.org/10.1101/276998; this version posted January 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Adrenergic agonist induces rhythmic firing in quiescent cardiac preganglionic neurons in nucleus ambiguous via activation of intrinsic membrane excitability Isamu Aiba and Jeffrey L. Noebels Department of Neurology, Baylor College of Medicine Houston TX 77030 Correspondence: Department of Neurology, Baylor College of Medicine, One Baylor Plaza, Houston ,Texas 77030. Tel: 713 798 5862, email: [email protected]. Tel: 713 798 5860, email: [email protected] Running Head: Adrenergic activation of cardiac vagal neurons 1 bioRxiv preprint doi: https://doi.org/10.1101/276998; this version posted January 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Abstract Cholinergic vagal nerves projecting from neurons in the brainstem nucleus ambiguus (NAm) play a predominant role in cardiac parasympathetic pacemaking control. Central adrenergic signaling modulates the tone of this vagal output; however the exact excitability mechanisms are not fully understood. We investigated responses of NAm neurons to adrenergic agonists using in vitro mouse brainstem slices. Preganglionic NAm neurons were identified by Chat-tdtomato fluorescence in young adult transgenic mice and their cardiac projection confirmed by retrograde dye tracing. Juxtacellular recordings detected sparse or absent spontaneous action potentials (AP) in NAm neurons. However bath application of epinephrine or norepinephrine strongly and reversibly activated most NAm neurons regardless of their basal firing rate.
    [Show full text]
  • Gene Therapy for Recurrent Laryngeal Nerve Injury
    G C A T T A C G G C A T genes Review Gene Therapy for Recurrent Laryngeal Nerve Injury Koji Araki * ID , Hiroshi Suzuki, Kosuke Uno ID , Masayuki Tomifuji and Akihiro Shiotani Department of Otolaryngology-Head & Neck Surgery, National Defense Medical College, Saitama 3598513, Japan; [email protected] (H.S.); [email protected] (K.U.); [email protected] (M.T.); [email protected] (A.S.) * Correspondence: [email protected]; Tel.: +81-4-2995-1686 Received: 2 June 2018; Accepted: 20 June 2018; Published: 25 June 2018 Abstract: Recurrent laryngeal nerve (RLN) injury has considerable clinical implications, including voice and swallowing dysfunction, which may considerably impair the patient’s quality of life. Recovery of vocal fold movement is an essential novel treatment option for RLN injury. The potential of gene therapy for addressing this issue is highly promising. The target sites for RLN gene therapy are the central nervous system, nerve fibers, laryngeal muscles, and vocal cord mucosa. Gene transduction has been reported in each site using viral or non-viral methods. The major issues ensuing after RLN injury are loss of motoneurons in the nucleus ambiguus, degeneration and poor regeneration of nerve fibers and motor end plates, and laryngeal muscle atrophy. Gene therapy using neurotrophic factors has been assessed for most of these issues, and its efficacy has been reported. Another important matter for functional vocal fold movement recovery is misdirected regeneration, in which the wrong neurons may innervate other laryngeal muscles, where even if innervation is reestablished, proper motor function is not restored.
    [Show full text]
  • The Vestibulo-Cochlear Nerve (Cranial Nerve 8) (Vestibular & Auditory Pathways)
    The Vestibulo-cochlear Nerve (Cranial Nerve 8) (Vestibular & Auditory Pathways) By : Prof. Ahmed Fathalla & Dr. Sanaa AlShaarawy OBJECTIVES At the end of the lecture, the students should be able to: qList the nuclei related to vestibular and cochlear nerves in the brain stem. qDescribe the type and site of each nucleus. qDescribe the vestibular pathways and its main connections. qDescribe the auditory pathway and its main connections. BRAIN – VENTRAL SURFACE Ponto-medullary Sulcus (cerebello- pontine angle) Vestibulo-Cochlear Nerve • Type: Special sensory (SSA) • Conveys impulses from inner ear to nervous system. • Components: § Vestibular part: conveys impulses associated with body posture ,balance and coordination of head & eye movements. § Cochlear part: conveys impulses associated with hearing. • Vestibular & cochlear parts leave the ventral surface of brain stem through the pontomedullary sulcus ‘at crebellopontine angle’ (lateral to facial nerve), run laterally in posterior cranial fossa and enter the internal acoustic meatus along with 7th nerve. Vestibular Nerve • The cell bodies (1st order neurons) are Vestibular nuclei belong to located in the vestibular ganglion special somatic afferent within the internal auditory meatus. column in brain stem. • The Peripheral processes (vestibular nerve fibers) make dendritic contact with hair cells of the membranous labyrinth (inner ear). 2 • The central processes (form the vestibular nerve) ‘’Efferent Fibres’’ : 1. Mostly end up in the lateral, medial, inferior and superior 1 vestibular nuclei (2nd order neurons) of the rostral medulla, located beneath the lateral part of the floor of 4th ventricle 2. Some fibers go to the cerebellum through the inferior cerebellar peduncle • Other Efferents from the vestibular nuclei project to other regions for the maintenance of balance, conscious awareness of vestibular stimulation , co-ordination of head & eye movements and control the posture.
    [Show full text]
  • Lecture 6: Cranial Nerves
    Lecture 6: Cranial Nerves Objective: To understand the organization of cranial nerves with respect to their nuclei within the brain, their course through and exit from the brain, and their functional roles. Olfactory Eye Muscles 3, 4 &6 Cranial Nerves 1-7 I overview Table, Page 49 II Lecture notes Cranial Nerves and their Functions V Trigeminal VII Facial VIII IX X XII XI Cranial Nerves 8-12 Overview sternocephalic I. Factors Responsible for the Complex Internal Organization of the Brain Stem-> leads to altered location of cranial nerve nuclei in adult brain stem 1. Development of the Fourth Ventricle a. Medulla and Pons develop ventral to the 4th ventricle cerebellum b. Alar plate is displaced lateral to basal plate 4 Medulla Developing Neural Tube 2. Cranial nerve nuclei form discontinuous columns Rostral 12 SE Page 48 Notes 3. Some cranial nerve nuclei migrate from their primitive embryonic positions (e.g., nuclei of V and VII) Facial N. Factors responsible for the complex internal organization of the brainstem: 4) Special senses develop in association with the brain stem. Nuclei of special senses 5) Development of the cerebellum and its connections Cerebellum II. Cranial Nerve Nuclei: Nucleus = column of neuron cell bodies. Efferent nuclei are composed of cell bodies of alpha or gamma motor neurons (SE) or preganglionic parasympathetic neurons (VE). III. Motor Efferent Nuclei (Basal Plate Derivatives): 1. SE (Somatic Efferent) Nuclei: SE neurons form two longitudinally oriented but discontinuous columns of cell bodies in the brain stem. Neurons that comprise these columns are responsible for innervating all of the skeletal musculature of the head.
    [Show full text]