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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. -
Basal Ganglia & Cerebellum
1/2/2019 This power point is made available as an educational resource or study aid for your use only. This presentation may not be duplicated for others and should not be redistributed or posted anywhere on the internet or on any personal websites. Your use of this resource is with the acknowledgment and acceptance of those restrictions. Basal Ganglia & Cerebellum – a quick overview MHD-Neuroanatomy – Neuroscience Block Gregory Gruener, MD, MBA, MHPE Vice Dean for Education, SSOM Professor, Department of Neurology LUHS a member of Trinity Health Outcomes you want to accomplish Basal ganglia review Define and identify the major divisions of the basal ganglia List the major basal ganglia functional loops and roles List the components of the basal ganglia functional “circuitry” and associated neurotransmitters Describe the direct and indirect motor pathways and relevance/role of the substantia nigra compacta 1 1/2/2019 Basal Ganglia Terminology Striatum Caudate nucleus Nucleus accumbens Putamen Globus pallidus (pallidum) internal segment (GPi) external segment (GPe) Subthalamic nucleus Substantia nigra compact part (SNc) reticular part (SNr) Basal ganglia “circuitry” • BG have no major outputs to LMNs – Influence LMNs via the cerebral cortex • Input to striatum from cortex is excitatory – Glutamate is the neurotransmitter • Principal output from BG is via GPi + SNr – Output to thalamus, GABA is the neurotransmitter • Thalamocortical projections are excitatory – Concerned with motor “intention” • Balance of excitatory & inhibitory inputs to striatum, determine whether thalamus is suppressed BG circuits are parallel loops • Motor loop – Concerned with learned movements • Cognitive loop – Concerned with motor “intention” • Limbic loop – Emotional aspects of movements • Oculomotor loop – Concerned with voluntary saccades (fast eye-movements) 2 1/2/2019 Basal ganglia “circuitry” Cortex Striatum Thalamus GPi + SNr Nolte. -
Imaging of the Confused Patient: Toxic Metabolic Disorders Dara G
Imaging of the Confused Patient: Toxic Metabolic Disorders Dara G. Jamieson, M.D. Weill Cornell Medicine, New York, NY The patient who presents with either acute or subacute confusion, in the absence of a clearly defined speech disorder and focality on neurological examination that would indicate an underlying mass lesion, needs to be evaluated for a multitude of neurological conditions. Many of the conditions that produce the recent onset of alteration in mental status, that ranges from mild confusion to florid delirium, may be due to infectious or inflammatory conditions that warrant acute intervention such as antimicrobial drugs, steroids or plasma exchange. However, some patients with recent onset of confusion have an underlying toxic-metabolic disorders indicating a specific diagnosis with need for appropriate treatment. The clinical presentations of some patients may indicate the diagnosis (e.g. hypoglycemia, chronic alcoholism) while the imaging patterns must be recognized to make the diagnosis in other patients. Toxic-metabolic disorders constitute a group of diseases and syndromes with diverse causes and clinical presentations. Many toxic-metabolic disorders have no specific neuroimaging correlates, either at early clinical stages or when florid symptoms develop. However, some toxic-metabolic disorders have characteristic abnormalities on neuroimaging, as certain areas of the central nervous system appear particularly vulnerable to specific toxins and metabolic perturbations. Areas of particular vulnerability in the brain include: 1) areas of high-oxygen demand (e.g. basal ganglia, cerebellum, hippocampus), 2) the cerebral white matter and 3) the mid-brain. Brain areas of high-oxygen demand are particularly vulnerable to toxins that interfere with cellular respiratory metabolism. -
Neuron Numbers Increase in the Human Amygdala from Birth to Adulthood, but Not in Autism
Neuron numbers increase in the human amygdala from birth to adulthood, but not in autism Thomas A. Avinoa, Nicole Bargera, Martha V. Vargasa, Erin L. Carlsona, David G. Amarala,b,c, Melissa D. Baumana,b, and Cynthia M. Schumanna,1 aDepartment of Psychiatry and Behavioral Sciences, UC Davis MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA 95817; bCalifornia National Primate Research Center, University of California, Davis, CA 95616; and cCenter for Neuroscience, University of California, Davis, CA 95618 Edited by Joseph E. LeDoux, New York University, New York, NY, and approved March 1, 2018 (received for review February 12, 2018) Remarkably little is known about the postnatal cellular develop- process, however, may also make the amygdala more susceptible ment of the human amygdala. It plays a central role in mediating to developmental or environmental insults. emotional behavior and has an unusually protracted development ASD is characterized by impairments in social communication well into adulthood, increasing in size by 40% from youth to combined with restricted interests and behaviors. Alterations in adulthood. Variation from this typical neurodevelopmental trajec- amygdala growth can be detected as early as 2 y of age (23–26) tory could have profound implications on normal emotional devel- and persist into late childhood (5, 27). The severity of the indi- vidual’s social and communicative symptoms positively correlates opment. We report the results of a stereological analysis of the – number of neurons in amygdala nuclei of 52 human brains ranging with amygdala enlargement, suggesting a potential structure from 2 to 48 years of age [24 neurotypical and 28 autism spectrum function relationship (23). -
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. -
Digital Neuroanatomy
DIGITAL NEUROANATOMY LM NEUROHISTOLOGY George R. Leichnetz, Ph.D. Professor, Department of Anatomy & Neurobiology Virginia Commonwealth University 2004 Press the Å and Æ keys on your keyboard to navigate through this lecture There are three morphological types of neurons in the nervous system: unipolar, bipolar, and multipolar. While all three types can be found in the PNS, the CNS only contains multipolar neurons. CNS multipolar neurons vary greatly in morphology: eg. spinal cord motor neurons, pyramidal cells of cerebral cortex, Purkinje cells of cerebellar cortex. The supportive cells of the CNS are neuroglia: astrocytes, oligodendrocytes, and microglia. Oligodendrocytes myelinate CNS axons, while Schwann cells myelinate PNS axons. Protoplasmic astrocytes predominate in CNS gray matter, while fibrous astrocytes predominate in CNS white matter. The ventral horn of the spinal cord Lumbar Spinal Cord contains multipolar motor neurons. Dorsal White Horn Matter Gray Matter Ventral Kluver- Horn Barrera Stain (LFB & CV) Cell bodies of motor neurons Dendrite Gray Matter Dendrite Perineuronal H & E oligodendrocyte Stain Nucleus, nucleolus Abundant Nissl substance Dorsal root Dorsal root ganglion Ventral root Gray Matter: contains White Matter: cell bodies of neurons contains x-sections of myelinated axons Multipolar motor neurons Silver Stain of the ventral horn Large multipolar motor neurons of the spinal cord ventral horn: see nucleus, nucleolus, abundant Nissl substance, multiple tapering processes (dendrites). The axon hillock (origin of axon from cell body) lacks Nissl. Nucleus Axon hillock dendrites Nucleolus Nissl substance (RER) Kluver-Barrera Stain (Luxol Fast Blue and Cresyl Violet) Thoracic Spinal Cord The nucleus dorsalis of Clarke, located in the base of the dorsal horn of the thoracic spinal cord, contains multipolar neurons whose nucleus is eccentric and Nissl around the periphery of the cell body (as if it were chromatolytic). -
Review of Spinal Cord Basics of Neuroanatomy Brain Meninges
Review of Spinal Cord with Basics of Neuroanatomy Brain Meninges Prof. D.H. Pauža Parts of Nervous System Review of Spinal Cord with Basics of Neuroanatomy Brain Meninges Prof. D.H. Pauža Neurons and Neuroglia Neuron Human brain contains per 1011-12 (trillions) neurons Body (soma) Perikaryon Nissl substance or Tigroid Dendrites Axon Myelin Terminals Synapses Neuronal types Unipolar, pseudounipolar, bipolar, multipolar Afferent (sensory, centripetal) Efferent (motor, centrifugal, effector) Associate (interneurons) Synapse Presynaptic membrane Postsynaptic membrane, receptors Synaptic cleft Synaptic vesicles, neuromediator Mitochondria In human brain – neurons 1011 (100 trillions) Synapses – 1015 (quadrillions) Neuromediators •Acetylcholine •Noradrenaline •Serotonin •GABA •Endorphin •Encephalin •P substance •Neuronal nitric oxide Adrenergic nerve ending. There are many 50-nm-diameter vesicles (arrow) with dark, electron-dense cores containing norepinephrine. x40,000. Cell Types of Neuroglia Astrocytes - Oligodendrocytes – Ependimocytes - Microglia Astrocytes – a part of hemoencephalic barrier Oligodendrocytes Ependimocytes and microglial cells Microglia represent the endogenous brain defense and immune system, which is responsible for CNS protection against various types of pathogenic factors. After invading the CNS, microglial precursors disseminate relatively homogeneously throughout the neural tissue and acquire a specific phenotype, which clearly distinguish them from their precursors, the blood-derived monocytes. The ´resting´ microglia -
Nucleus Laminaris
OUP UNCORRECTED PROOF – FIRST-PROOF, 26/03/2010, GLYPH 1 2 2 2 Nucleus Laminaris 3 Yuan Wang Jason Tait Sanchez , and Edwin W Rubel 4 Our ability to detect subtle acoustic cues in noisy environments, like a con- 5 versation in a crowded restaurant, is one benefi t of binaural hearing. Binaural 6 hearing is also essential for sound localization. The ability to localize the 7 source of a sound is dependent on time disparities in the arrival of low- 8 frequency signals between the two ears, referred to as interaural time differ- 9 ence (ITD). In all vertebrates, ITDs are encoded by distinct neural circuits in 10 the central auditory nervous system specialized for the temporal processing 11 of sound at the network, synaptic, and cellular levels. Coding of ITDs is fi rst 12 performed by the medial superior olive (MSO) of mammals and by the 13 nucleus laminaris (NL) in birds and some reptiles. 14 This chapter will focus on the microcircuitry of the chicken NL, which is 15 an excellent example of neural architecture exquisitely tailored for its special- 16 ized function in sound localization. Neurons in NL are coincidence detectors, 17 encoding temporal information of sound arriving at the two ears by respond- 18 ing maximally when resulting action potentials (APs) arrive simultaneously, 19 a unique feature responsible for the coding of ITDs in the microsecond range. 20 We will discuss the important structural and functional specializations of NL 21 that optimize this specialized ability, fundamental for binaural hearing in 22 most birds and mammals. -
Different Projections of the Central Amygdaloid Nucleus Mediate Autonomic and Behavioral Correlates of Conditioned Fear
The Journal of Neuroscience, July 1988, 8(7): 2517-2529 Different Projections of the Central Amygdaloid Nucleus Mediate Autonomic and Behavioral Correlates of Conditioned Fear Joseph E. LeDoux, Jiro Iwata, Piera Cicchetti, and Donald J. Reis Division of Neurobiology, Cornell University Medical College, New York, New York 10021 The purpose of the present study was to determine whether Iwata et al., 1986a).The critical amygdaloid regionsare located lesions of areas projected to by the central amygdaloid nu- in the dorsal part of this structure, and include the lateral and cleus (ACE) would disrupt the classical conditioning of auto- central nuclei and the amygdalostriatal transition zone (Iwata nomic and/or behavioral emotional responses. The areas et al., 1986a; LeDoux et al., 1986a). Since the major projection studied included 3 projection targets of the ACE: the lateral from the acoustic thalamus terminates in the lateral nucleusand hypothalamic area (LH), midbrain central gray (CG) region, the amygdalostriatal zone (LeDoux et al., 1985), one of these and bed nucleus of the stria terminalis (BNST). Lesions were regionsprobably servesas the sensoryinterface of the amygdala made either electrolytically or by microinjection of ibotenic during conditioning (Cicchetti et al., 1987). In contrast, the acid, which destroys local neurons without interrupting fibers amygdaloid output pathway is likely to involve the central nu- of passage. Two weeks later, the animals were classically cleus, a structure implicated in the expressionof the autonomic -
Multistable Properties of Human Subthalamic Nucleus Neurons in Parkinson’S Disease
Multistable properties of human subthalamic nucleus neurons in Parkinson’s disease Jeremy W. Chopeka,1, Hans Hultbornb, and Robert M. Brownstonea,2 aDepartment of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG London, United Kingdom; and bDepartment of Neuroscience, University of Copenhagen, 2200 Copenhagen N, Denmark Edited by Peter L. Strick, University of Pittsburgh, Pittsburgh, PA, and approved October 15, 2019 (received for review July 18, 2019) To understand the function and dysfunction of neural circuits, it is thorough characterization of complex neuronal properties is necessary to understand the properties of the neurons participating critical for understanding the modus operandi of neural circuits. in the behavior, the connectivity between these neurons, and the The connectivity of the excitatory subthalamic nucleus (STN) neuromodulatory status of the circuits at the time they are producing of the basal ganglia is well understood: it receives inputs from the the behavior. Such knowledge of human neural circuits is difficult, globus pallidus externa (GPe), motor cortex, and substantia nigra at best, to obtain. Here, we study firing properties of human pars compacta, and projects to the GPe, globus pallidus interna, subthalamic neurons, using microelectrode recordings and microstim- and substantia nigra pars reticulata. Furthermore, the basic ulation during awake surgery for Parkinson’s disease. We dem- electrophysiological properties of these neurons is reasonably onstrate that low-amplitude, brief trains of microstimulation can lead well understood, with resurgent and persistent sodium- and to persistent changes in neuronal firing behavior including switching calcium-dependent potassium conductances playing key roles for between firing rates, entering silent periods, or firing several bursts repetitive firing, and low-threshold calcium currents playing a then entering a silent period. -
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. -
Cerebellar Histology & Circuitry
Cerebellar Histology & Circuitry Histology > Neurological System > Neurological System CEREBELLAR HISTOLOGY & CIRCUITRY SUMMARY OVERVIEW Gross Anatomy • The folding of the cerebellum into lobes, lobules, and folia allows it to assume a tightly packed, inconspicuous appearance in the posterior fossa. • The cerebellum has a vast surface area, however, and when stretched, it has a rostrocaudal expanse of roughly 120 centimeters, which allows it to hold an estimated one hundred billion granule cells — more cells than exist within the entire cerebral cortex. - It is presumed that the cerebellum's extraordinary cell count plays an important role in the remarkable rehabilitation commonly observed in cerebellar stroke. Histology Two main classes of cerebellar nuclei • Cerebellar cortical neurons • Deep cerebellar nuclei CEREBELLAR CORTICAL CELL LAYERS Internal to external: Subcortical white matter Granule layer (highly cellular) • Contains granule cells, Golgi cells, and unipolar brush cells. Purkinje layer 1 / 9 • Single layer of large Purkinje cell bodies. • Purkinje cells project a fine axon through the granule cell layer. - Purkinje cells possess a large dendritic system that arborizes (branches) extensively and a single fine axon. Molecular layer • Primarily comprises cell processes but also contains stellate and basket cells. DEEP CEREBELLAR NUCLEI From medial to lateral: Fastigial Globose Emboliform Dentate The globose and emboliform nuclei are also known as the interposed nuclei • A classic acronym for the lateral to medial organization of the deep nuclei is "Don't Eat Greasy Food," for dentate, emboliform, globose, and fastigial. NEURONS/FUNCTIONAL MODULES • Fastigial nucleus plays a role in the vestibulo- and spinocerebellum. • Interposed nuclei are part of the spinocerebellum. • Dentate nucleus is part of the pontocerebellum.