* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 1 - U-System
Lateralization of brain function wikipedia , lookup
Subventricular zone wikipedia , lookup
Broca's area wikipedia , lookup
Neuropsychopharmacology wikipedia , lookup
Biology of depression wikipedia , lookup
Executive functions wikipedia , lookup
Limbic system wikipedia , lookup
Development of the nervous system wikipedia , lookup
Optogenetics wikipedia , lookup
Embodied language processing wikipedia , lookup
Environmental enrichment wikipedia , lookup
Neuroplasticity wikipedia , lookup
Affective neuroscience wikipedia , lookup
Time perception wikipedia , lookup
Premovement neuronal activity wikipedia , lookup
Aging brain wikipedia , lookup
Neuroesthetics wikipedia , lookup
Emotional lateralization wikipedia , lookup
Human brain wikipedia , lookup
Synaptic gating wikipedia , lookup
Neuroeconomics wikipedia , lookup
Neuroanatomy of memory wikipedia , lookup
Apical dendrite wikipedia , lookup
Cortical cooling wikipedia , lookup
Neural correlates of consciousness wikipedia , lookup
Orbitofrontal cortex wikipedia , lookup
Eyeblink conditioning wikipedia , lookup
Anatomy of the cerebellum wikipedia , lookup
Cognitive neuroscience of music wikipedia , lookup
Prefrontal cortex wikipedia , lookup
Insular cortex wikipedia , lookup
Feature detection (nervous system) wikipedia , lookup
Motor cortex wikipedia , lookup
1. Cerebral Cortex - six-layered neocortex in all areas except hippocampus and olfactory areas near uncus Cell types Pyramidal cells- numerous; large, cone-shaped, apex toward cortical surface with long apical dendrite; basal dendrites from base of pyramid and extends horizontally in cortex; principal output neurons of cortex; axon towards white matter Nonpyramidal cells- small, multipolar, short axons; also called stellate cells; principal interneurons of cortex (some with GABAergic inhibitory output) Layering Molecular (Plexiform) Layer – Layer 1; few neurons, synaptic interactions occur here (certain incoming fibers end on apical dendrites) - Beneath plexiform layer are four alternating layers with different proportions of cell types: - Layers 3 and 5 are pyramidal; pyramidal cells in layer 3 send axons to other cortical areas; those in layer 5 send axons to striatum and spinal cord - Layer 4 is nonpyramidal; incoming fibers from thalamic relay end in layer 4 - Layer 2 is a mix of nonpyramidal and small pyramidal cells - Layer 6 is a mix of pyramidal cells and some spindle-shaped modified pyramidal cells; send axons to thalamus - Areas processing incoming info are thin, have lots of small nonpyramidal and pyramidal cells, and few big pyramidal cells; this is granular cortex (primary sensory areas) - Motor cortex is thick and has lots of big pyramidal cells overwhelming the small cells (agranular cortex) 2. Columnar organization - apical and basal dendrites of pyramidal cells are a reflection of two perpendicular directions of cortical organization - columns run perpendicular to cortical surface - columns in visual cortex, somatosensory cortex, prefrontal cortex - Cortical areas project to other areas in same hemisphere (ipsilateral); to neighboring areas via short U-fibers that dip under one or two sulci; to faraway areas through longer association bundles (arcuate fasciculus is one that arcs above insula and interconnects anterior and posterior parts of a hemisphere including Broca’s and Wernicke’s area) 3. – Corpus callosum is the largest commissure in the CNS; it interconnects most areas of each hemisphere’s cortex with mirror-image and other sites in the contralateral hemisphere - the temporal lobe sends many of its interconnecting fibers through the anterior commissure (contains a few crossing olfactory fibers) Cortical Maps - Each elemental function, like somatic sensation, vision or voluntary movement, has a primary cortical area associated with it - Each function also has a nearby association area that works on more complicated aspects of the same function; these unimodal association areas have higher THs, larger/bilateral receptive fields, and more complex properties - destruction of primary somatosensory cortex causes a somatosensory deficit, but not a total loss; this is true because there is parallel processing occurring (thalamic info goes to both primary and association areas, which can function by themselves) - there are also more complex (multimodal) association areas that receive multiple types of info, and cortical areas involved in limbic function 4. Primary areas - Primary somatosensory cortex occupies postcentral gyrus and is made up of 3 strips (3 1 2 from anterior to posterior) - Primary auditory cortex is hidden in lateral sulcus, in transverse temporal gyri on top of the temporal lobe - Primary visual cortex is in the walls of the calcarine sulcus - Primary motor cortex (large corticospinal neurons) occupies precentral gyrus 5. Unimodal (simple) association areas - Primary visual cortex surrounded by two concentric belts of visual association cortex filling up rest of occipital lobe (additional visual areas exist in temporal lobe) - Auditory association cortex is lateral to primary auditory cortex and occupies most of superior temporal gyrus - Somatosensory association cortex is in superior parietal lobule and its continuation onto medial surface of parietal lobe; 2nd mapping of body surface in parietal lobe, looking like a distorted mirror image of the one in primary somatosensory cortex (head at bottom of postcentral gyrus, body onto insula – second somatosensory area) - Premotor cortex is a anterior to primary motor cortex; association area for motor system; part of Premotor cortex anterior to where head is represented contains frontal eye field, responsible for triggering voluntary rapid eye movements (saccades) to contralateral side; motor association cortex has supplementary motor area on medial side of hemisphere 6. Complex (multimodal) association areas 1. Parietal-occipital-temporal junction receives and integrates multiple kinds of information; it is made up of angular and supramarginal gyri 2. Large area of frontal lobe in front of motor and premotor cortex, on both the lateral and medial surfaces of the hemisphere; this is called prefrontal cortex - Language functions contained within these multimodal association areas - Broca’s area occupies the opercular and triangular parts of the left inferior frontal gyrus; damage here causes problems producing language - Wernicke’s area is the posterior part of the left auditory association cortex; damage here causes problems comprehending language 7. Limbic areas - The cingulate and parahippocampal gyri, the orbital cortex and insula, and the anterior end of the temporal lobe associated with hippocampus and amygdala limbic cortex