DOCSLIB.ORG

Nucleus Dorsalis Superficialis (Lateralis Dorsalis) of the Thalamus and the Limbic System in Man

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Nucleus Dorsalis Superficialis (Lateralis Dorsalis) of the Thalamus and the Limbic System in Man J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.765 on 1 July 1974. Downloaded from Joutrnal of Neur)ology, Neurosurgery, and Psychiatry, 1974, 37, 765-789 Nucleus dorsalis superficialis (lateralis dorsalis) of the thalamus and the limbic system in man J. M. VAN BUREN AND R. C. BORKE Fr-om the Surgical Neurology Branch, National Institute of Neurological Diseases and Str-oke, National Institutes of Health, Bethesda, Maryland, U.S.A. SYNOPSIS Although the earlier supposition was that the n. dorsalis superficialis (n. lateralis dorsalis) of the thalamus projected to the parietal region, more recent evidence has linked it to the posterior cingulate gyrus and possibly adjacent regions near the splenium of the corpus callosum. An afferent supply from lower levels was in more doubt, although some report had been made of cell and fibre degeneration in the n. dorsalis superficialis after extensive temporal resections and section of the fornix in lower primates. The five human hemispheres of the present study all had lesions of long duration below the level of the splenium of the corpus callosum in the posteromedial temporal region. All showed marked degeneration in the fornix and n. dorsalis superficialis. In favourably Protected by copyright. stained cases, gliotic fascicles could be followed from the descending column of the fornix to the n. dorsalis superficialis via the region lateral to the stria medullaris thalami. The cell loss in the nucleus thus appeared to be an instance of anterograde transynaptic degeneration. These cases provided an interesting instance in which human infarctions provided natural lesions that would have been hard to duplicate in experimental animals. In man, the n. dorsalis superficialis (n. lateralis extent, to the cortex of areas 5 and 7.' Support dorsalis) lies on the superior surface of the for this concept was supplied by studies in the thalamus above the n. medialis (n. medialis macaque (Walker, 1938a), chimpanzee (Walker, dorsalis) and is contiguous with the pulvinar 1938b, c), and in man (Papez, 1939; Clark and posteriorly. Anteriorly, it extends a conical pro- Russell, 1940; Hartmann and Simma, 1952; cess medial to the posterior tapering extension Szabo, 1952). On the other hand, some dis- of the anterior nuclei. It is separated from the crepancies appeared. Ranson et al. (1941) re- http://jnnp.bmj.com/ thalamic surface and the adjacent nuclei by a ported a case of removal of the lateroposterior thin and somewhat variable medullated lamina. frontal, parietal, anterior occipital, and posterior In general, the background myelination of the temporal cerebral cortex including the opercula nucleus is very light, making it readily distin- and the cortex of the insula in the macaque that guishable by the naked eye on myelin prepara- had caused no degeneration in the n. lateralis tions. However, a variable pattern of fascicles dorsalis. may enter the nucleus from the stratum zonale Closer inspection of the positive material gives on September 24, 2021 by guest. lateral to the nucleus or the ventral myelinated some hint as to the basis for the discrepancy in lamina. This may lead to a parcellated or marbled results. Of Walker's three cases with degenera- appearance accounting for the designation, n. tion in LD, two (experiments 12L and 17) had disseminati dorsalis, used by Riley (1943). extension of the parietooccipital ablation to In the early work there was little to suggest include the medial surface down to the corpus that the nucleus belonged to the limbic system. callosum. In the remaining case (12R), the Walker (1938a, p. 185) concluded that, 'It is cortical removal extended down the midline only quite apparent that this nucleus [n. lateralis to the callosomarginal sulcus resulting in cell dorsalis] is largely related to the posterior part of loss in the inferior part of LD but leaving the the postcentral convolution and, to a lesser dorsal part intact. 765 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.765 on 1 July 1974. Downloaded from 766 J. M. Van Buren and R. C. Borke Some of the human material (Clark and hippocampal gyrus and anterior lingula (cases Russell, 1940; Sheps, 1945; Szabo, 1952; 149, 150, 151, 152). Simma, 1954) with degeneration in n. dorsalis The present report presents in detail the serial superficialis quite obviously had extension of the section reconstructions of five human hemi- lesion onto the medial aspect of the hemisphere. spheres, all of which had degeneration of the n. This was not so, however, in the cases of Papez dorsalis superficialis and fornix in association (1939) and Hartmann and Simma (1952). In with lesions in the medial posterior temporal these cases, however, the lesion extended down region below the level of the splenium of the to the wall of the cerebral ventricle and thus corpus callosum. The lesion was thus outside the would be in a position to interrupt thalamo- commonly accepted posterior limbic projection cortical fibres looping around the superolateral area of the nucleus. aspect of the ventricle to reach the medial aspect of the As is often the case with human material, hemisphere. lesions tend to be multiple. In the present study, The likelihood that the n. dorsalis superficialis the associated infarcts of the lingula and n. has important efferent connections to the medial ventralis caudalis thalami were the most trouble- aspect of the parietal region-that is, cortex some. The importance of these extraneous bordering the interhemispheral sulcus-receives lesions has been discounted by the authors on support from studies in the macaque. Krieg the basis of the appearance of degeneration in n. (1963) reported that after lesions in the retro- and dorsalis superficialis when these regions were suprasplenial cortex (areas 23 and 31) there was intact and experience with other cases (VanProtected by copyright. cell degeneration in LD (n. lateralis dorsalis or Buren and Borke, 1972a) which serve as control n. dorsalis superficialis). Locke et al. (1964) con- material. firmed this in cases of posterior cingulate abla- tions. Niimi and Tsutsui's (1962) observations in a single animal were similar. Both Krieg and METHODS Locke et al. noted lack of complete degeneration The five hemispheres had been prepared with immer- in LD after lesions of the posterior cingulate sion fixation, total embedding in celloidin and serial region, suggesting the possibility of additional section at 35 ,um. Adjacent sections at 20 section areas of projection. intervals were stained respectively with cresyl violet and for myelin (Loyez method) and mounted on Afferent connections to the n. dorsalis super- large glass slides. ficialis have also been found from the posterior Reconstruction work was begun by making prints cingulate region. With the Marchi technique, of every 100th section of the myelin series at about Larson (1962) noted a sparse but definite projec- 4 x and every 40th section through the thalamus at http://jnnp.bmj.com/ tion to the nucleus from area 23 in the macaque. 12 x of the cresyl violet series on Kodak Photo- With similar preparations, Krieg (1963, p. 223, mechanical T paper. The 10 second processor avail- 230) reported fibres from both the retro- and able for this paper was a great convenience. On these suprasplenial cortex (areas 23 and 31) to the n. prints the areas of damage and degeneration were dorsalis superficialis. Domesick (1969) in the rat marked with a soft pencil after inspection with a traced fibre degeneration from lesions in the stereomicroscope (10-40 diameter magnification). dorsal part of the posterior cingulate region Thus the term 'neuronal degeneration' used here refers quite simply to loss of neuronal population of on September 24, 2021 by guest. (Rose's agranular retrosplenial cortex) to LD. varying degree. No attempt was made to evaluate A final interesting observation has been made intrinsic cell change-for example, chromatolysis. by Pasik et al. (1960) and Siqueira (1965) in the Postmortem autolytic changes made such evaluations monkey. After extensive temporal lobectomies, of doubtful value. 'Gliosis' refers to areas of definite degeneration was apparent in the n. dorsalis increase in glial nuclei giving the region a darker background than adjacent areas. 'Myelin loss' was superficialis which they felt was proportional in likewise a designation made on low power observa- intensity to the degree of damage to the hippo- tion. The cardinal concept applied to the studies was campal formation. One may remember that that the changes were of three-dimensional nature Krieg (1963) found no Marchi evidence of and thus must be visible in sequential sections of the corticothalamic projection from the posterior series. Adherence to this principle tended to mini- J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.765 on 1 July 1974. Downloaded from Nucleus dorsalis superficialis in man 767 TABLE 1 macaque, Olszewski (1952) was forced to add a PRESENT HUMAN THALAMIC AND 'nucleus X' in this area. HYPOTHALAMIC NOMENCLATURE* The present system essentially follows that of Vogt and Vogt (1941) including a few of the many A pr N. anteroprincipalis (combined n. anteromedialis and n. modifications introduced by Hassler (1959). In the anteroventralis) authors' experience many of the smaller divisions of Ce N. centralis (n. centrum medianum) Co N. commissuralis (n. centralis medialis) Hassler did not hold up well in a considerable series D c N. dorsocaudalis (n. lateralis posterior) of serial section reconstructions of the human D o N. dorsooralis (n. ventralis lateralis, dorsal part) D sf N. dorsalis superficialis (n. lateralis dorsalis) thalamus. They thus appeared more as features of a Fa N. fasciculosus (n. ventralis anterior, medial part) particular specimen brain rather than the general G I Corpus geniculatum laterale human thalamus. The details and justification for G m Corpus geniculatum mediale H Habenula this system are given elsewhere (Van Buren and H m N.
Load more

Recommended publications
  • Introduction
    Cambridge University Press 978-1-316-64693-9 — The Brain and Behavior 4th Edition Excerpt More Information Chapter1 Introduction Introduction Theneuraxisinthehumanrunsasanimaginary straight line through the center of the spinal cord Human behavior is a direct reflection of the anatomy and brainstem (Figure 1.1). At the level of the junc- and physiology of the central nervous system. The goal tion of the midbrain and diencephalon, however, the of the behavioral neuroscientist is to uncover the neu- neuraxis changes orientation and extends from the roanatomical substrates of behavior. Complex mental occipital pole to the frontal pole (Figure 1.1). processes are represented in the brain by their elemen- The neuraxis located above the midbrain is the neur- tary components. Elaborate mental functions consist of axis of the cerebrum and is sometimes called the subfunctions and are constructed from both serial and horizontal neuraxis. A cross-section taken perpendi- parallel interconnections of several brain regions. cular to the horizontal neuraxis is called a coronal An introduction to the nervous system covers general (frontal) section. terminology and the ventricular system. With regard to the neuraxis of the spinal cord and brainstem: Major Subdivisions • Dorsal (posterior) means toward the back. The nervous system is divided anatomically into the • Ventral (anterior) means toward the abdomen. central nervous system (CNS) and the peripheral ner- • Rostral means toward the nose. vous system (PNS). • Caudal means toward the tail. • The CNS is made up of the brain and spinal cord. • The sagittal (midsagittal) plane is the vertical • The PNS consists of the cranial nerves and spinal plane that passes through the neuraxis.
    [Show full text]
  • Neuroimaging Evidence Implicating Cerebellum in the Experience of Hypercapnia and Hunger for Air
    Neuroimaging evidence implicating cerebellum in the experience of hypercapnia and hunger for air Lawrence M. Parsons*†, Gary Egan‡, Mario Liotti*, Stephen Brannan*, Derek Denton‡, Robert Shade§, Rachael Robillard¶, Lisa Madden§, Bart Abplanalp¶, and Peter T. Fox* *Research Imaging Center, University of Texas Health Science Center, San Antonio, TX 78284; ‡Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3052, Australia; §Southwest Foundation for Biomedical Research, P. O. Box 760549, San Antonio, TX 78245-0549; and ¶Departments of Psychology and Educational Psychology, University of Texas, Austin, TX 78712 Contributed by Derek Denton, December 20, 2000 Recent neuroimaging and neurological data implicate cerebellum areas (20–23). Anatomical tracer labeling data in rat (24) in nonmotor sensory, cognitive, vegetative, and affective func- indicate that a number of cerebellar areas send and͞or receive tions. The present study assessed cerebellar responses when the projections from the VRG, which contains the structures nec- urge to breathe is stimulated by inhaled CO2. Ventilation changes essary for respiratory rhythm generation (25–30). The cerebellar follow arterial blood partial pressure CO2 changes sensed by the areas connected to the VRG are quadrangular (VI), central medullary ventral respiratory group (VRG) and hypothalamus, (III), lingula (I, II), and inferior semilunar (Crus II) lobules, as entraining changes in midbrain, pons, thalamus, limbic, paralimbic, well as fastigial nucleus, interposed nucleus, and dentate nuclei, and insular regions. Nearly all these areas are known to connect the output nuclei for the vermal, intermediate, and lateral anatomically with the cerebellum. Using positron emission tomog- regions of cerebellum. Moreover, cerebellum has known con- raphy, we measured regional brain blood flow during acute CO2- nectivity to the hypothalamus, thalamus, pons, and midbrain induced breathlessness in humans.
    [Show full text]
  • The Cerebellum: 3
    41 The Cerebellum: 3. Anatomic-MR Correlation in the Coronal Plane Gary A. Press 1 Thin (5-mm) coronal high-field (1.5-T) MR images of four human brain specimens and James W. Murakami2 14 normal volunteers were correlated with myelin-stained microtomic sections of the Eric Courchesne2 specimen cerebella. The primary white-matter tracts innervating several hemispheric Marjorie Grafe3 (posterior quadrangular, superior, and inferior semilunar, gracile, biventer, tonsil) and John R. Hesselink1 vermian (declive, folium, tuber) lobules are oriented perpendicularly to the coronal plane of section and are shown well on proton-density-weighted (long TR/short TE) and T2- weighted (long TR/Iong TE) spin-echo images, which provide excellent contrast between gray and white matter. Several of the surface sulci and fissures of the cerebellar hemispheres (including the superior posterior, horizontal, secondary, and posterolateral fissures) also course perpendicular to the coronal plane and are depicted well on T1- weighted (short TR/short TE) and T2-weighted images, which maximize contrast be­ tween CSF and parenchyma. The opportunity for side-to-side comparison of the hemi­ spheres is a distinct advantage of the coronal view. Nevertheless, more obliquely oriented surfaces (preculminate, primary, inferior posterior, inferior anterior, and intra­ biventral fissures) and deep hemispheric structures (primary white-matter tracts to central, anterior quadrangular, and floccular lobules) may be obscured by volume­ averaging in the coronal plane; moreover, much of the finer anatomy of the vermis is depicted poorly. The constant surface and deep anatomy of the cerebellum revealed on coronal images in normal volunteers encourages detailed mapping. MR imaging in the coronal plane should be especially useful in identifying, localizing, and quantifying normal and abnormal morphologic differences between the cerebellar hemispheres.
    [Show full text]
  • Is Composed from Spinal Cord and Brain
    doc. MUDr. Adriana Boleková, PhD. MVDr. Natália Hvizdošová, PhD. CENTRAL NERVOUS SYSTEM – is composed from spinal cord and brain SPINAL CORD cranial border: foramen magnum, pyramidal decussation, exit of first pair of spinal nerves caudal border: level of L1 – L2 vertebrae medullary cone – filum terminale (S2) – cauda equina enlargements: cervical enlargement (C5 – Th1): origin of nerves for upper extremity – brachial plexus lumbosacral enlargement (L1 – S2): origin of nerves for lower extremity – lumbosacral plexus external features: anterior median fissure anterolateral sulcus – anterior roots of spinal nn. posterolateral sulcus – posterior roots of spinal nn. posterior median sulcus posterior intermediate sulcus internal features: White matter anterior funiculus (between anterior median fissure and anterolateral sulcus) lateral funiculus (between anterolateral and posterolateral sulci) posterior funiculus (between posterolateral sulcus and posterior median sulcus) fasciculus gracilis fasciculus cuneatus Gray matter anterior (ventral) horn – motor function: Rexed laminae I – VI lateral horn – serves to visceral function: Rexed lamina VII dorsal (posterior) horn – sensory information: Rexed laminae VIII – IX central grey matter – interneurons: around central canal Rexed lamina X Central canal cranially opens into IV. ventricle caudally expands into terminal ventricle vessels of spinal cord: Arteries: spinal brr. from surrounding arteries – anterior radicular aa., posterior radicular aa.: posterior spinal aa. (in posterolateral
    [Show full text]
  • Neuroimaging Evidence Implicating Cerebellum in Support of Sensory Cognitive Processes Associated with Thirst
    Neuroimaging evidence implicating cerebellum in support of sensory͞cognitive processes associated with thirst Lawrence M. Parsons*†, Derek Denton‡, Gary Egan‡, Michael McKinley‡, Robert Shade‡, Jack Lancaster*, and Peter T. Fox* *Research Imaging Center, Medical School, University of Texas Health Science Center at San Antonio, Floyd Curl Drive, San Antonio, TX 78284; ‡Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3052, Australia; and §Southwest Foundation for Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549 Contributed by Derek A. Denton, December 13, 1999 Recent studies implicate the cerebellum, long considered strictly a and tactile discrimination, kinesthetic sensation, and working motor control structure, in cognitive, sensory, and affective phe- memory, among other processes (6–12). It has been proposed nomenon. The cerebellum, a phylogenetically ancient structure, that the lateral cerebellum may be activated during several has reciprocal ancient connections to the hypothalamus, a struc- motor, perceptual, and cognitive processes specifically because ture important in vegetative functions. The present study investi- of the requirement to monitor and adjust the acquisition of gated whether the cerebellum was involved in vegetative func- sensory data (2, 13). Furthermore, there are reports suggesting tions and the primal emotions engendered by them. Using positron the involvement of posterior vermal cerebellum in affect (14, 15). emission tomography, we examined the effects on the cerebellum The findings implicating the cerebellum in sensory processing of the rise of plasma sodium concentration and the emergence of and emotional states make it of great interest to examine thirst in 10 healthy adults. The correlation of regional cerebral whether the cerebellum has a role in basic vegetative functions blood flow with subjects’ ratings of thirst showed major activation and the primal emotions thus generated, particularly given the in the vermal central lobule.
    [Show full text]
  • Computed Tomography of the Brain Stem with Intrathecal Metrizamide. Part I: the Normal Brain Stem
    Computed Tomography of the Brain Stem with Intrathecal Metrizamide. Part I: The Normal Brain Stem Michel E. Mawad 1 Detailed anatomy of the brain stem and cervicomedullary junction can be accurately A. John Silver demonstrated with metrizamide computed tomographic cisternography. Specifically. Sadek K. Hilal surface anatomy is unusually well outlined. Nine distinct and easily recognizable levels S. Ramaiah Ganti of section are described: four levels in the medulla, three in the pons, and two in the mesencephalon. Surface features of the brain stem, fine details in the floor of the fourth ventricle, cranial nerves, and vascular structures are shown and discussed. Reliably accurate imaging of the brain stem and cervicomedullary junction has now become available using high-resolution computed tomographic (CT) scan­ ning following intrathecal admini stration of metrizamide [1 -6]. The demonstration of surface features of the brain stem such as the ventral fissure, ventrolateral su lcus, pyramids, and olivary protuberance has become commonplace; suc h details have not been routinely demonstrable in the past. Many authors [1, 2] have already emphasized the value of metrizamide CT cisternography and its superiority to both angiography and pneumoencephalog­ raphy. These latter procedures rely on subtle displacement of vessels or distor­ tion of the air-filled fourth ventricle and posterior fossa cisterns. Compared with air, metrizamide spreads much more readily in th e entire subarachnoid space without the problem of meniscus formation or " air lock. " CT permits the sepa­ ration of the various collections of contrast agent and avoids th e superimposition of features encountered in nontomographic contrast studies. Improved visualization of the details of the brain stem by metrizamide CT has allowed the detection of subtle morphologic changes in the brain stem and subarachnoid space not previously appreciated.
    [Show full text]
  • Modulatory Effects of Theta Burst Stimulation on Cerebellar Nonsomatic Functions
    Cerebellum (2011) 10:495–503 DOI 10.1007/s12311-010-0230-5 Modulatory Effects of Theta Burst Stimulation on Cerebellar Nonsomatic Functions Asli Demirtas-Tatlidede & Catarina Freitas & Alvaro Pascual-Leone & Jeremy D. Schmahmann Published online: 7 December 2010 # Springer Science+Business Media, LLC 2010 Abstract Clinical and functional imaging studies suggest the Profile of Mood States test. All 36 sessions of cerebellar that the cerebellar vermis is involved in the regulation of a stimulation were tolerated well without serious adverse range of nonsomatic functions including cardiovascular events. Cardiovascular monitoring pointed to a mild but control, thirst, feeding behavior, and primal emotions. significant decrease in heart rate subsequent to vermal Cerebello-hypothalamic circuits have been postulated to stimulation; no changes were detected in systolic or be a potential neuroanatomical substrate underlying this diastolic blood pressure measurements. Subjective ratings modulation. We tested this putative relationship between detected a significant increase in Thirst and a trend toward the cerebellar vermis and nonsomatic functions by stimu- increased Appetite following vermal stimulation. These lating the cerebellum noninvasively via neuronavigated observations are consistent with existing neurophysiological transcranial magnetic stimulation. In this randomized, and neuroimaging data indicating a role for the cerebellum in counter-balanced, within-subject study, intermittent theta the regulation of visceral responses. In conjunction with the burst stimulation (TBS) was applied on three different days modulatory function of the cerebellum, our results suggest a to the vermis and the right and left cerebellar hemispheres role for the vermis in somatovisceral integration likely of 12 right-handed normal subjects with the aim of through cerebello-hypothalamic pathways.
    [Show full text]
  • Identification of Novel Pathways Associated with Patterned
    International Journal of Molecular Sciences Article Identification of Novel Pathways Associated with Patterned Cerebellar Purkinje Neuron Degeneration in Niemann-Pick Disease, Type C1 Kyle B. Martin 1, Ian M. Williams 1, Celine V. Cluzeau 1, Antony Cougnoux 1, Ryan K. Dale 2, James R. Iben 3, Niamh X. Cawley 1, Christopher A. Wassif 1 and Forbes D. Porter 1,* 1 Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA; [email protected] (K.B.M.); [email protected] (I.M.W.); [email protected] (C.V.C.); [email protected] (A.C.); [email protected] (N.X.C.); [email protected] (C.A.W.) 2 Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA; [email protected] 3 Molecular Genomics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-301-435-4432 Received: 7 December 2019; Accepted: 25 December 2019; Published: 31 December 2019 Abstract: Niemann-Pick disease, type C1 (NPC1) is a lysosomal disease characterized by progressive cerebellar ataxia. In NPC1, a defect in cholesterol transport leads to endolysosomal storage of cholesterol and decreased cholesterol bioavailability. Purkinje neurons are sensitive to the loss of NPC1 function.
    [Show full text]
  • The Cerebellum in Sagittal Plane-Anatomic-MR Correlation: 1
    659 The Cerebellum in Sagittal Plane-Anatomic-MR Correlation: 1. The Vermis Eric Courchesne 1 Correlation of thin (5-mm) sagittal high-field (1.5-T) MR images of three brain speci­ Gary A. Press2 mens and 11 normal volunteers with microtome sections of the human cerebellar vermis James Murakami1 and hemispheres demonstrates that proton-density-weighted (long TR/short TE) and Dean Berthoty2 T2-weighted (long TR/Iong TE) spin-echo pulse sequences provide the greatest contrast Marjorie Grafe3 between gray and white matter. These images also can display (1) the corpus medullare and primary white-matter branches to the vermian lobules, including the lingula, cen­ Clayton A. Wiley3 2 tralis, culmen, declive, folium, tuber, pyramis, uvula, and nodulus; and (2) several finer John R. Hesselink secondary branches to individual folia within the lobules. Surface features of the vermis including the deeper fissures (e.g., preculminate, primary, horizontal, and prepyramidal) and shallower sulci are best delineated by T1-weighted (short TR/short TE) and T2- weighted images, which provide greatest contrast between CSF and parenchyma. Given that the width of the normal vermis varied from 6 to 12 mm in our volunteers, the acquisition of thin slices (:S 5 mm) was required to minimize volume averaging of the cerebellar hemispheres with the vermis on a midline sagittal MR section. Knowledge of the detailed normal anatomy of the cerebellar vermis on sagittal MR images can assist in the identification of various pathologic alterations. Previous reports provided initial descriptions of normal and pathologic anatomy of the posterior fossa contents at low [1-3], moderate [4, 5], and high [6-9] MR field strengths.
    [Show full text]
  • Nonmotor Functions of the Cerebellum: an Introduction
    Published March 3, 2016 as 10.3174/ajnr.A4720 FUNCTIONAL VIGNETTE Nonmotor Functions of the Cerebellum: An Introduction X A.P. Klein, X J.L. Ulmer, X S.A. Quinet, X V. Mathews, and X L.P. Mark he concept of nonmotor functions of the cerebellum (little gorizes the cerebellum into the vestibulocerebellum (archicer- Tcerebrum)1 is an intriguing proposal that has garnered little ebellum), spinocerebellum (paleocerebellum), and cerebrocer- attention in the past but has become a relatively recent focal point ebellum (neocerebellum) (Fig 2).11 The oldest portion, the for neuroscience investigators. The preponderance of anatomic vestibulocerebellum, primarily receives input fibers from the ves- and clinical evidence supporting the traditional view of the cere- tibular system. The phylogenetically intermediate component, bellum as a motor mechanism has understandably overwhelmed the spinocerebellum, receives fiber input directly from the spinal the sporadic reports of behavioral and intellectual dysfunction cord. The newest part, the cerebrocerebellum, receives input from associated with cerebellar pathology during the 19th and most many different areas of the cerebral cortex. Interesting observa- of the 20th century.2-7 Developments during the past 25 years, tions from fMRI studies, however, offer a different type of cere- coinciding with the development of functional MR imaging, bellar organization based on function. Mapping of cognitive however, have greatly increased our awareness and under- functions shows a lateral cerebellar distribution, while the senso- standing of cerebellar cognitive functions. Neuroimaging in rimotor cerebellar functions are more medially located (Fig 3).12 conjunction with anatomic and clinical investigations is help- This medial-to-lateral functional gradient also applies to the ing to cultivate new ways of thinking about cerebellar organi- group of 3 deep cerebellar nuclei (fastigial; interposed, consisting zation and function.
    [Show full text]
  • Anatomy of the Cerebellum Computational Models of Neural
    Anatomy of the Cerebellum The Brain©s GPU Computational Models of neural Systems Lecture 2.1 David S. Touretzky September, 2017 First Look cerebellum 10/14/17 Computational Models of Neural Systems 2 Lateral View 10/14/17 Computational Models of Neural Systems 3 Ventral View 10/14/17 Computational Models of Neural Systems 4 Basic Facts About the Cerebellum ● Latin for ªlittle brainº. ● An older brain area, with a simple, regular architecture. ● Makes up 10% of brain volume, but contains over 50% of the brain©s neurons and 4X the neurons of the cerebral cortex. ● Huge fan-in: 40X as many axons enter the cerebellum as exit from it. ● Necessary for smooth, accurate performance of motor actions. ● Example: moving your arm rapidly in a circle. – Involves many muscles in the arm, trunk, and legs. ● People can still move without a cerebellum, but their actions will not be coordinated. There can be overshoots and oscillations. 10/14/17 Computational Models of Neural Systems 5 Cortical Projections to Cerebellum From Strick et al., Annual review of Neuroscience (2009), adapted from Glickstein et al. (1985) J. Comparative Neurology 10/14/17 Computational Models of Neural Systems 6 Three Cerebellar Lobes ● Anterior (divided into 3 lobules) ● Posterior (divided into 6 lobules) ● Flocculonodular 10/14/17 Computational Models of Neural Systems 7 10 Lobules Lingula, Central, Culmen, Declive, Folium, Tuber, Pyramis, Uvula, Tonsil, Flocculonodular 10/14/17 Computational Models of Neural Systems 8 8 of the 10 Lobules 1. Lingula 2. Central Lobule 3. Culmen 4. Declive 5. Folium 6. Tuber 7. Pyramis 8.
    [Show full text]
  • Cerebellar Cortex Morphology of the Red Sokoto Goat (Capri Hircus): Foliation Pattern
    International Journal of Brain and Cognitive Sciences 2017, 6(3): 58-64 DOI: 10.5923/j.ijbcs.20170603.03 Cerebellar Cortex Morphology of the Red Sokoto Goat (Capri Hircus): Foliation Pattern Byanet O.*, Joshua D. Mkaanem Department of Veterinary Anatomy, College of Veterinary Medicine, University of Agriculture Abstract Morphological analysis of the cerebellar cortex was done on the red Sokoto goats, with the aim of providing reference baseline data in this species. Results from the nine cerebella examined revealed the mean cerebellar weight of 10.2 ± 0.38g, this accounted for 14% of the total brain weight. The cerebellar mean length 4.9 ± 0.13cm, was close to its width 4.4 ± 0.16cm were very close. The cerebellar surface was complexly foliated, with a well-developed central vermis the cerebellar hemispheres and paraflocculus. The lingula, central lobule and culmen were placed cranioventrally and were not visible on the dorsal view. The declive was the largest lobule in the rostral lobe, having five sublobules. The broader lobules in the caudal lobe were Folium vermis and Tuber vermis, each had two parts; (lobule VIA, VIB) and (lobules VIIA, VIIB), respectively with their sublobules. Furthermore, lobule IX was the third large lobules in this lobe with four sublobules (IXa - IXd). In conclusion, the relatively small sizes of lingula, central and culmen lobules may be correlated with the characteristic short and erect tail of the animal. In addition, the well-developed bilateral cerebellar hemispheres and paraflocculus in red Sokoto goat may be related to the animal high motor activities such as climbing, standing erect on the hindlimbs, with the forelimb suspended in the air to grasps leaves of short trees and shrubs in its ecological regions.
    [Show full text]