Neuron: Structure Neuron: Function

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What are the Neurons building blocks and of nervous system? Brain 1. Neurons 2. Glia: supports neurons Neuron: Structure Neuron: Structure Three basic parts: • Axon terminals 1. Cell body 2. Axon •Synapse 3. Dendrites Neuron: Function specialized in • Receiving • Transmitting • Processing information One way transmission: from dendrites to axon 1 How Neurons Communicate One way transmission: from dendrites to axon. 1. Electrical 2. Chemical 1. Electrical signals 1 (b) Action potential • Resting Potential - sudden change in the electrical charge across the neuron’s membrane - electrical system in equilibrium - all-or-none response (polarization of ions) (threshold) Synapse How Neurons Communicate? Neurotransmitters 2. Chemical Transmission 2 effects: 1. Excitatory generate action potential in the next neuron 2. Inhibitory more difficult for the second neuron to fire 2 Damage Brain 1-2. Medulla & Pons 3 • control heart rate & breathing 3 Main Parts 2 • carry visual & auditory information 1 • respiration • movement 1. Hindbrain • facial expression • sleep 2. Midbrain Damage to Pons: 3. Forebrain Locked-in syndrome 3. Reticular formation I. Hindbrain 4. Cerebellum a) Filters sensory information “little brain” b) Regulate overall arousal in the brain Coordinated motor activity • If damaged - sleepy or aroused; Damage: poorly coordinated muscle functioning -coma 3 II. Midbrain III. Forebrain Involve in 1. Thalamus - Vision - Receive -Hearing - Filter - Organize - Pain-relieving function -Transmit - Some motor movements information from our senses (except smell) to other parts of the brain 2. Hypothalamus • Eating & drinking (amount of nutrition stored in cells) • Aggression Regulates: Sexual behavior 3. Limbic system b) Amygdala a) Hippocampus: organizes memory functioning emotions damage - inability to store • stimulation – elicit aggression & rage new information • damage – reduces aggression 4 4. Cerebral Cortex Corpus Callosum 2 hemispheres Corpus callosum A set of axons connecting the two hemispheres Split-Brain Phenomenon 4 regions or lobes 1. Occipital Lobe 2. Parietal Lobe Vision a) spatial awareness “neglect” phenomenon Damage: • “Blindness” • Face-blindness • Inability to recognize colors • Motion-blindness 5 2. Parietal Lobe 3. Frontal lobe a) Primary Motor Cortex Sensory Cortex Processes information about pain, touch, temperature 4. Temporal Lobe 3. Frontal lobe -hearing b) “executive system “ - some aspects of vision - Planing Damage to the L hemisphere - Decision making inability to understand spoken words - Forming concepts Damage to the R hemisphere - Processing & storing information recognize speech, but not organizations of sound (melody, tune) -Self-regulation 6.

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Oligodendrocytes in Development, Myelin Generation and Beyond
cells Review Oligodendrocytes in Development, Myelin Generation and Beyond Sarah Kuhn y, Laura Gritti y, Daniel Crooks and Yvonne Dombrowski * Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast BT9 7BL, UK; [email protected] (S.K.); [email protected] (L.G.); [email protected] (D.C.) * Correspondence: [email protected]; Tel.: +0044-28-9097-6127 These authors contributed equally. y Received: 15 October 2019; Accepted: 7 November 2019; Published: 12 November 2019 Abstract: Oligodendrocytes are the myelinating cells of the central nervous system (CNS) that are generated from oligodendrocyte progenitor cells (OPC). OPC are distributed throughout the CNS and represent a pool of migratory and proliferative adult progenitor cells that can diﬀerentiate into oligodendrocytes. The central function of oligodendrocytes is to generate myelin, which is an extended membrane from the cell that wraps tightly around axons. Due to this energy consuming process and the associated high metabolic turnover oligodendrocytes are vulnerable to cytotoxic and excitotoxic factors. Oligodendrocyte pathology is therefore evident in a range of disorders including multiple sclerosis, schizophrenia and Alzheimer’s disease. Deceased oligodendrocytes can be replenished from the adult OPC pool and lost myelin can be regenerated during remyelination, which can prevent axonal degeneration and can restore function. Cell population studies have recently identiﬁed novel immunomodulatory functions of oligodendrocytes, the implications of which, e.g., for diseases with primary oligodendrocyte pathology, are not yet clear. Here, we review the journey of oligodendrocytes from the embryonic stage to their role in homeostasis and their fate in disease. We will also discuss the most common models used to study oligodendrocytes and describe newly discovered functions of oligodendrocytes.
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bioRxiv preprint doi: https://doi.org/10.1101/2020.03.06.981373; this version posted March 8, 2020. 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. Evidence for oligodendrocyte progenitor cell heterogeneity in the adult mouse brain. Authors: Rebecca M. Beiter1,2, Anthony Fernández-Castañeda1,2, Courtney Rivet-Noor1,2, Andrea Merchak1,2, Robin Bai1, Erica Slogar1, Scott M. Seki1,2,3, Dorian A Rosen1,4, Christopher C. Overall1,5, and Alban Gaultier1,5,# 1Center for Brain Immunology and Glia, Department of Neuroscience, 2Graduate Program in Neuroscience, 3Medical Scientist Training Program, 4Graduate Program in Pharmacological Sciences School of Medicine, University of Virginia, Charlottesville, VA 22908, USA. #Corresponding author. Email: [email protected] 5Christopher C. Overall and Alban Gaultier are co-senior authors 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.03.06.981373; this version posted March 8, 2020. 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 Oligodendrocyte progenitor cells (OPCs) are a mitotically active population of glia that comprise approximately 5% of the adult brain. OPCs maintain their proliferative capacity and ability to differentiate in oligodendrocytes throughout adulthood, but relatively few mature oligodendrocytes are produced following developmental myelination. Recent work has begun to demonstrate that OPCs likely perform multiple functions in both homeostasis and disease, and can significantly impact behavioral phenotypes such as food intake and depressive symptoms. However, the exact mechanisms through which OPCs might influence brain function remains unclear.
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