Brainstem and Thalamus

Total Page：16

File Type：pdf, Size：1020Kb

Brainstem and Thalamus The brainstem is like a tube that begins underneath the brain and extends down until it becomes part of the spinal cord. It is has three areas: the midbrain, pons and medulla. The brainstem is very important because it handles automatic functions like breathing and heart rate. The thalamus is a small structure located slightly above the brainstem. It is the gateway for most of the sensory pathways. The thalamus plays a role in regulating awareness and emotional aspects of sensory experiences (reaction to fear or hunger, for example). Symptoms of brainstem and/or thalamus injury depend on the extent and specific location of the injury. The following symptoms may occur: problems controlling blood pressure problems with sight and eye movement problems with breathing problems closing eyes and moving face decreased wakefulness/arousal problems with hearing and balance problems swallowing or coughing Another condition that may occur when there are injuries near the brainstem and thalamus is “storming.” Storming is also called hypothalamic instability or paroxysmal sympathetic storms. A storming episode may happen as a result of a stimulus or when the person is resting quietly. It may last several minutes and can happen at various times throughout the day. Signs of storming include an increase in heart rate, temperature and sweating. There also may be a rise in the blood pressure and muscle stiffness or rigidity during the episode. Storming happens 1 Brainstem and Thalamus because the injured brain is having difficulty controlling “automatic” bodily functions. Episodes of storming often decrease as the brain heals and the person becomes more responsive. Sometimes the doctor may order certain medicines to help decrease some of the symptoms of storming. 2 .

Copy Link

Recommended publications

Magnetic Resonance Imaging of Multiple Sclerosis: a Study of Pulse-Technique Efficacy
691 Magnetic Resonance Imaging of Multiple Sclerosis: A Study of Pulse-Technique Efficacy Val M. Runge1 Forty-two patients with the clinical diagnosis of multiple sclerosis were examined by Ann C. Price1 proton magnetic resonance imaging (MRI) at 0.5 T. An extensive protocol was used to Howard S. Kirshner2 facilitate a comparison of the efficacy of different pulse techniques. Results were also Joseph H. Allen 1 compared in 39 cases with high-resolution x-ray computed tomography (CT). MRI revealed characteristic abnormalities in each case, whereas CT was positive in only 15 C. Leon Partain 1 of 33 patients. Milder grades 1 and 2 disease were usually undetected by CT, and in all A. Everette James, Jr.1 cases, the abnormalities noted on MRI were much more extensive than on CT. Cerebral abnormalities were best shown with the T2-weighted spin-echo sequence (TE/TR = 120/1000); brainstem lesions were best defined on the inversion-recovery sequence (TE/TI/TR =30/400/1250). Increasing TE to 120 msec and TR to 2000 msec heightened the contrast between normal and abnormal white matter. However, the signal intensity of cerebrospinal fluid with this pulse technique obscured some abnormalities. The diagnosis of multiple sclerosis continues to be a clinical challenge [1,2). The lack of an objective means of assessment further complicates the evaluation of treatment regimens. Evoked potentials, cerebrospinal fluid (CSF) analysis , and computed tomography (CT) are currently used for diagnosis, but all lack sensitivity and/or specificity. Furthermore, postmortem examinations demonstrate many more lesions than those suggested by clinical means [3).
[Show full text]
Cortex and Thalamus Lecture.Pptx
Cerebral Cortex and Thalamus Hyperbrain Ch 2 Monica Vetter, PhD January 24, 2013 Learning Objectives: • Anatomy of the lobes of the cortex • Relationship of thalamus to cortex • Layers and connectivity of the cortex • Vascular supply to cortex • Understand the location and function of hypothalamus and pituitary • Anatomy of the basal ganglia • Primary functions of the different lobes/ cortical regions – neurological findings 1 Types of Cortex • Sensory (Primary) • Motor (Primary) • Unimodal association • Multimodal association - necessary for language, reason, plan, imagine, create Note: • Gyri • Sulci • Fissures • Lobes 2 The Thalamus is highly interconnected with the cerebral cortex, and handles most information traveling to or from the cortex. “Specific thalamic Ignore nuclei” – have well- names of defined sensory or thalamic nuclei for motor functions now - A few Other nuclei have will more distributed reappear later function 3 Thalamus Midbrain Pons Limbic lobe = cingulate gyrus Structure of Neocortex (6 layers) white matter gray matter Pyramidal cells 4 Connectivity of neurons in different cortical layers Afferents = inputs Efferents = outputs (reciprocal) brainstem etc Eg. Motor – Eg. Sensory – more efferent more afferent output input Cortico- cortical From Thalamus To spinal cord, brainstem etc. To Thalamus Afferent and efferent connections to different ….Depending on whether they have more layers of cortex afferent or efferent connections 5 Different areas of cortex were defined by differences in layer thickness, and size and
[Show full text]
Brainstem: Structure & Its Mode of Action
Journal of Neurology & Neurophysiology 2021, Vol.12, Issue 3, 521 Opinion Brainstem: Structure & Its Mode of action Karthikeyan Rupani Research Fellow, Tata Medical Centre, India. Corresponding Author* The brainstem is exceptionally little, making up around as it were 2.6 percent of the brain's add up to weight. It has the basic parts of directing cardiac, and Rupani K, respiratory work, making a difference to control heart rate and breathing rate. Research Fellow, Tata Medical Centre, India; It moreover gives the most engine and tactile nerve supply to the confront and E-mail: [email protected] neck by means of the cranial nerves. Ten sets of cranial nerves come from the brainstem. Other parts incorporate the direction of the central apprehensive Copyright: 2021 Rupani K. This is an open-access article distributed under the framework and the body's sleep cycle. It is additionally of prime significance terms of the Creative Commons Attribution License, which permits unrestricted within the movement of engine and tangible pathways from the rest of the use, distribution, and reproduction in any medium, provided the original author brain to the body, and from the body back to the brain. These pathways and source are credited. incorporate the corticospinal tract (engine work), the dorsal column-medial lemniscus pathway and the spinothalamic tract [3]. The primary part of the brainstem we'll consider is the midbrain. The midbrain Received 01 March 2021; Accepted 15 March 2021; Published 22 March 2021 (too known as the mesencephalon) is the foremost prevalent of the three districts of the brainstem. It acts as a conduit between the forebrain over and the pons and cerebellum underneath.
[Show full text]
The Human Thalamus Is an Integrative Hub for Functional Brain Networks
5594 • The Journal of Neuroscience, June 7, 2017 • 37(23):5594–5607 Behavioral/Cognitive The Human Thalamus Is an Integrative Hub for Functional Brain Networks X Kai Hwang, Maxwell A. Bertolero, XWilliam B. Liu, and XMark D’Esposito Helen Wills Neuroscience Institute and Department of Psychology, University of California, Berkeley, Berkeley, California 94720 The thalamus is globally connected with distributed cortical regions, yet the functional significance of this extensive thalamocortical connectivityremainslargelyunknown.Byperforminggraph-theoreticanalysesonthalamocorticalfunctionalconnectivitydatacollected from human participants, we found that most thalamic subdivisions display network properties that are capable of integrating multi- modal information across diverse cortical functional networks. From a meta-analysis of a large dataset of functional brain-imaging experiments, we further found that the thalamus is involved in multiple cognitive functions. Finally, we found that focal thalamic lesions in humans have widespread distal effects, disrupting the modular organization of cortical functional networks. This converging evidence suggests that the human thalamus is a critical hub region that could integrate diverse information being processed throughout the cerebral cortex as well as maintain the modular structure of cortical functional networks. Key words: brain networks; diaschisis; functional connectivity; graph theory; thalamus Significance Statement The thalamus is traditionally viewed as a passive relay station of information from sensory organs or subcortical structures to the cortex. However, the thalamus has extensive connections with the entire cerebral cortex, which can also serve to integrate infor- mation processing between cortical regions. In this study, we demonstrate that multiple thalamic subdivisions display network properties that are capable of integrating information across multiple functional brain networks. Moreover, the thalamus is engaged by tasks requiring multiple cognitive functions.
[Show full text]
Basal Ganglia Anatomy, Physiology, and Function Ns201c
Basal Ganglia Anatomy, Physiology, and Function NS201c Human Basal Ganglia Anatomy Basal Ganglia Circuits: The ‘Classical’ Model of Direct and Indirect Pathway Function Motor Cortex Premotor Cortex + Glutamate Striatum GPe GPi/SNr Dopamine + - GABA - Motor Thalamus SNc STN Analagous rodent basal ganglia nuclei Gross anatomy of the striatum: gateway to the basal ganglia rodent Dorsomedial striatum: -Inputs predominantly from mPFC, thalamus, VTA Dorsolateral striatum: -Inputs from sensorimotor cortex, thalamus, SNc Ventral striatum: Striatal subregions: Dorsomedial (caudate) -Inputs from vPFC, hippocampus, amygdala, Dorsolateral (putamen) thalamus, VTA Ventral (nucleus accumbens) Gross anatomy of the striatum: patch and matrix compartments Patch/Striosome: -substance P -mu-opioid receptor Matrix: -ChAT and AChE -somatostatin Microanatomy of the striatum: cell types Projection neurons: MSN: medium spiny neuron (GABA) •striatonigral projecting – ‘direct pathway’ •striatopallidal projecting – ‘indirect pathway’ Interneurons: FS: fast-spiking interneuron (GABA) LTS: low-threshold spiking interneuron (GABA) LA: large aspiny neuron (ACh) 30 um Cellular properties of striatal neurons Microanatomy of the striatum: striatal microcircuits • Feedforward inhibition (mediated by fast-spiking interneurons) • Lateral feedback inhibition (mediated by MSN collaterals) Basal Ganglia Circuits: The ‘Classical’ Model of Direct and Indirect Pathway Function Motor Cortex Premotor Cortex + Glutamate Striatum GPe GPi/SNr Dopamine + - GABA - Motor Thalamus SNc STN The simplified ‘classical’ model of basal ganglia circuit function • Information encoded as firing rate • Basal ganglia circuit is linear and unidirectional • Dopamine exerts opposing effects on direct and indirect pathway MSNs Basal ganglia motor circuit: direct pathway Motor Cortex Premotor Cortex Glutamate Striatum GPe GPi/SNr Dopamine + GABA Motor Thalamus SNc STN Direct pathway MSNs express: D1, M4 receptors, Sub.
[Show full text]
Dopamine Neuron Diversity: Recent Advances and Current Challenges in Human Stem Cell Models and Single Cell Sequencing
cells Review Dopamine Neuron Diversity: Recent Advances and Current Challenges in Human Stem Cell Models and Single Cell Sequencing Alessandro Fiorenzano * , Edoardo Sozzi, Malin Parmar and Petter Storm Developmental and Regenerative Neurobiology, Wallenberg Neuroscience Center, and Lund Stem Cell Centre, Department of Experimental Medical Science, Lund University, 22184 Lund, Sweden; [email protected] (E.S.); [email protected] (M.P.); [email protected] (P.S.) * Correspondence: alessandro.fi[email protected]; Tel.: +46-462220549 Abstract: Human midbrain dopamine (DA) neurons are a heterogeneous group of cells that share a common neurotransmitter phenotype and are in close anatomical proximity but display different functions, sensitivity to degeneration, and axonal innervation targets. The A9 DA neuron subtype controls motor function and is primarily degenerated in Parkinson’s disease (PD), whereas A10 neurons are largely unaffected by the condition, and their dysfunction is associated with neuropsy- chiatric disorders. Currently, DA neurons can only be reliably classified on the basis of topographical features, including anatomical location in the midbrain and projection targets in the forebrain. No systematic molecular classification at the genome-wide level has been proposed to date. Although many years of scientific efforts in embryonic and adult mouse brain have positioned us to better understand the complexity of DA neuron biology, many biological phenomena specific to humans are Citation: Fiorenzano, A.; Sozzi, E.; not amenable to being reproduced in animal models. The establishment of human cell-based systems Parmar, M.; Storm, P. Dopamine combined with advanced computational single-cell transcriptomics holds great promise for decoding Neuron Diversity: Recent Advances the mechanisms underlying maturation and diversification of human DA neurons, and linking their and Current Challenges in Human Stem Cell Models and Single Cell molecular heterogeneity to functions in the midbrain.
[Show full text]
The Thalamus: Gateway to the Mind Lawrence M
Overview The thalamus: gateway to the mind Lawrence M. Ward∗ The thalamus of the brain is far more than the simple sensory relay it was long thought to be. From its location at the top of the brain stem it interacts directly with nearly every part of the brain. Its dense loops into and out of cortex render it functionally a seventh cortical layer. Moreover, it receives and sends connections to most subcortical areas as well. Of course it does function as a very sophisticated sensory relay and thus is of vital importance to perception. But also it functions critically in all mental operations, including attention, memory, and consciousness, likely in different ways for different processes, as indicated by the consequences of damage to its various nuclei as well as by invasive studies in nonhuman animals. It plays a critical role also in the arousal system of the brain, in emotion, in movement, and in coordinating cortical computations. Given these important functional roles, and the dearth of knowledge about the details of its nonsensory nuclei, it is an attractive target for intensive study in the future, particularly in regard to its role in healthy and impaired cognitive functioning. © 2013 John Wiley & Sons, Ltd. How to cite this article: WIREs Cogn Sci 2013. doi: 10.1002/wcs.1256 INTRODUCTION and other animals can do quite well without major chunks of cortex. Indeed, decorticate rats behave very pen nearly any textbook of neuroscience or similarly to normal rats in many ways,2 whereas sensation and perception and you will ﬁnd the O de-thalamate rats die.
[Show full text]
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.
[Show full text]
Lecture 12 Notes
Somatic regions Limbic regions These functionally distinct regions continue rostrally into the ‘tweenbrain. Fig 11-4 Courtesy of MIT Press. Used with permission. Schneider, G. E. Brain structure and its Origins: In the Development and in Evolution of Behavior and the Mind. MIT Press, 2014. ISBN: 9780262026734. 1 Chapter 11, questions about the somatic regions: 4) There are motor neurons located in the midbrain. What movements do those motor neurons control? (These direct outputs of the midbrain are not a subject of much discussion in the chapter.) 5) At the base of the midbrain (ventral side) one finds a fiber bundle that shows great differences in relative size in different species. Give examples. What are the fibers called and where do they originate? 8) A decussating group of axons called the brachium conjunctivum also varies greatly in size in different species. It is largest in species with the largest neocortex but does not come from the neocortex. From which structure does it come? Where does it terminate? (Try to guess before you look it up.) 2 Motor neurons of the midbrain that control somatic muscles: the oculomotor nuclei of cranial nerves III and IV. At this level, the oculomotor nucleus of nerve III is present. Fibers from retina to Superior Colliculus Brachium of Inferior Colliculus (auditory pathway to thalamus, also to SC) Oculomotor nucleus Spinothalamic tract (somatosensory; some fibers terminate in SC) Medial lemniscus Cerebral peduncle: contains Red corticospinal + corticopontine fibers, + cortex to hindbrain fibers nucleus (n. ruber) Tectospinal tract Rubrospinal tract Courtesy of MIT Press. Used with permission. Schneider, G.
[Show full text]
Microstimulation of the Midbrain Tegmentum Creates Learning Signals for Saccade Adaptation
The Journal of Neuroscience, April 4, 2007 • 27(14):3759–3767 • 3759 Behavioral/Systems/Cognitive Microstimulation of the Midbrain Tegmentum Creates Learning Signals for Saccade Adaptation Yoshiko Kojima, Kaoru Yoshida, and Yoshiki Iwamoto Department of Neurophysiology, Doctoral Program in Kansei Behavioral and Brain Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8574, Japan Error signals are vital to motor learning. However, we know little about pathways that transmit error signals for learning in voluntary movements. Here we show that microstimulation of the midbrain tegmentum can induce learning in saccadic eye movements in mon- keys. Weak electrical stimuli delivered ϳ200 ms after saccades in one horizontal direction produced gradual and marked changes in saccade gain. The spatial and temporal characteristics of the produced changes were similar to those of adaptation induced by real visual error. When stimulation was applied after saccades in two different directions, endpoints of these saccades gradually shifted in the same direction in two dimensions. We conclude that microstimulation created powerful learning signals that dictate the direction of adaptive shift in movement endpoints. Our findings suggest that the error signals for saccade adaptation are conveyed in a pathway that courses through the midbrain tegmentum. Key words: motor learning; electrical stimulation; midbrain; saccade; adaptation; macaque; monkey Introduction superior colliculus, a key midbrain structure that issues saccade Motor learning ensures the accuracy of the movements we exe- signals to the premotor reticular circuitry (Scudder et al., 2002). cute daily. Vital to learning is the information about the error that The colliculus also has indirect access to the cerebellum via both results from executed movements.
[Show full text]
Brain Structure and Function Related to Headache
Review Cephalalgia 0(0) 1–26 ! International Headache Society 2018 Brain structure and function related Reprints and permissions: sagepub.co.uk/journalsPermissions.nav to headache: Brainstem structure and DOI: 10.1177/0333102418784698 function in headache journals.sagepub.com/home/cep Marta Vila-Pueyo1 , Jan Hoffmann2 , Marcela Romero-Reyes3 and Simon Akerman3 Abstract Objective: To review and discuss the literature relevant to the role of brainstem structure and function in headache. Background: Primary headache disorders, such as migraine and cluster headache, are considered disorders of the brain. As well as head-related pain, these headache disorders are also associated with other neurological symptoms, such as those related to sensory, homeostatic, autonomic, cognitive and affective processing that can all occur before, during or even after headache has ceased. Many imaging studies demonstrate activation in brainstem areas that appear specifically associated with headache disorders, especially migraine, which may be related to the mechanisms of many of these symptoms. This is further supported by preclinical studies, which demonstrate that modulation of specific brainstem nuclei alters sensory processing relevant to these symptoms, including headache, cranial autonomic responses and homeostatic mechanisms. Review focus: This review will specifically focus on the role of brainstem structures relevant to primary headaches, including medullary, pontine, and midbrain, and describe their functional role and how they relate to mechanisms
[Show full text]
Orienting Head Movements Resulting from Electrical Microstimulation of the Brainstem Tegmentum in the Barn Owl
The Journal of Neuroscience, January 1993, 13(l): 351370 Orienting Head Movements Resulting from Electrical Microstimulation of the Brainstem Tegmentum in the Barn Owl Tom Masino and Eric I. Knudsen Department of Neurobiology, Stanford University, Stanford, California 943055401 The size and direction of orienting movements are repre- movement latency, duration, velocity, and size each dem- sented systematically as a motor map in the optic tectum of onstrated dependencies on stimulus amplitude, frequency, the barn owl (du Lac and Knudsen, 1990). The optic tectum and duration. projects to several distinct regions in the medial brainstem The data demonstrate directly that at the level of the mid- tegmentum, which in turn project to the spinal cord (Masino brain tegmentum there exists a three-dimensional Cartesian and Knudsen, 1992). This study explores the hypothesis that representation of head-orienting movements such that hor- a fundamental transformation in the neural representation izontal, vertical, and roll components of movement are en- of orienting movements takes place in the brainstem teg- coded by anatomically distinct neural circuits. The data sug- mentum. Head movements evoked by electrical microstim- gest that in the projection from the optic tectum to these ulation in the brainstem tegmentum of the alert barn owl were medial tegmental regions, the topographic code for orienting cataloged and the sites of stimulation were reconstructed movement that originates in the tectum is transformed into histologically. Movements elicited from the brainstem teg- this Cartesian code. mentum were categorized into one of six different classes: [Key words: optic tectum, superior colliculus, saccadic saccadic head rotations, head translations, facial move- head movement, brainstem tegmentum, interstitial nucleus ments, vocalizations, limb movements, and twitches.
[Show full text]