Cerebral Cortex: Gondre-Lewis Flashcards
What is the Cerebral Cortex?
-external gray matter of the telencephalon -organized into layers -Necessary for higher cortical function. -Highest level of processing of information entering the brain -Serial processing between different parts of the cortex. (Primary, Secondary, etc.)
90% of the cerebral cortex is what?
Neocortex with 6 layers -has gray matter which is the cortical matter grouped neuronal cell bodies bunched together has basal ganglia/basal nuclei ?????
What is the most primitive layer of the cerebral cortex?
Archicortex “ancient”which has 3 layers and includes: -dentate -hippocampal gyri
Describe the paleocortex “old” philogenetic catergory of the cerebral cortex.
has 3-5 layers and includes: -rostral insular cortex -uncus -anterior perforated substance -primary olfactory cortex -entorhinal cortex occupies very little space
What is the gray matter of the cerebral hemisphere?
Cerebral Cortex Basal Nuclei
What is the white matter of the cerebral hemispheres?
Projection Fibers Commissural Fibers Association Fibers – short and long -Corpus callosum: a commissural axon -Internal capsule: projection fibers that pierce through the basal nuclei -Anterior commissure
Going micro to macro Cerebral Cortex –neuronal circuitry
Cerebral cortex has neurons and glia. NEURONS: projection neurons -other areas of cortex (ipsilateral, contralateral, or lateral) -subcortical areas interneurons (local circuit neurons) are GABAnergic neurons????? GLIA: -Oligodendrocytes -Microglia -Astrocytes
Relationship of GABA-ergic neurons with pyramidal neurons
-gabaergic control of pyramidal cells -Pyramidal neurons can be excited and inhibited by the neurotransmitters glutamate and GABA, respectively. GABA is the chief inhibitory NT
Dendritic arbors and spines
A dendritic spine (or spine) is a small membranous protrusion from a neuron’s dendrite that typically receives input from a single axon at the synapse. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron’s cell body -with intellectual disabilities you have decreased or fewer dendritic spines -some diseases have long and thin dendritic spins that still do not have capability to function
Different types of GABAergic interneurons
modulating behavior of the pyramidal cells -Chandelier cell -Double Bouquet Cell Large Basket Cell
Most projection neurons are
pyramidal cells which are excitatory
Most interneurons (local circuit neurons) are
non-pyramidal cells and are inhibitory (GABA)*
What are barbiturates and benzodiazepines?
-drugs that suppress the CNS and act as depressants -uses include sedation (anesthesia), anticonvulsants (seizure), antixiolytics (for anxiety) -are agonists at ionotropic GABA receptors
Area 17
lingual gyrus (upper visual) , cuneate gyrus (lower visual), calcarine fissure The visual cortex of the brain is a part of the cerebral cortex that processes visual information. It is located in the occipital lobe.
Brodmann area 4 refers to
the primary motor cortex of the human brain
What areas are primary sensory?
somatosensory: 3, 1, 2 Vision: 17 Auditory: 41
What areas are secondary sensory?
Vision: 18 Auditory: 42 Secondary motor: 6 Motor and speech: 44 and 45 ????
Describe the 6 layers of the neocortex.
Layers 1–>6 from the pial surface and down Layers I, II, III -Project to and receive input from intrahemispheric and interhemispheric cortex Layer IV -Receives Thalamocortical input Layer V -Projects to subcortical regions Layers VI -Projects to Thalamus
The thickness of the 6 layers varies according to function.
layer 4, which receives inputs from thalamus, is very thick in primary sensory but thin in primary motor areas. layer 5, which projects to the brainstem/spinal cord, is very thick in primary motor but thin in primary sensory areas.
What are the different types of fiber bundles coursing through the cortex?
-short U-fibers -longer associational bundles -commissures inclusive of corpus callosum and anterior commissure
Short U-Fibers Connect?
Adjacent Area of Cortex
Long Associational Bundles Connect?
Cortical Areas That are Far Away
Commissures connect?
Corpus Callosum: connects the right and left cerebral hemispheres; connects the left and right sides of the brain allowing for communication between both hemispheres; largest fiber tract (splenium, body, genu) Anterior Commissure: connecting the two temporal lobes of the cerebral hemispheres across the midline, and placed in front of the columns of the fornix; interconnects the right & left temporal lobes and olfactory tracts
VPL nucleus: ventral posterolateral nucleus (VPL) is a nucleus of the thalamus LGN goes to primary visual cortex MGN goes to primary auditory cortex
The VPL receives information from the neospinothalamic tract and the medial lemniscus of the posterior column-medial lemniscus pathway. It then projects this sensory information to Brodmann’s Areas 3, 1 and 2 in the postcentral gyrus. Collectively, Brodmann areas 3, 1 and 2 make up the primary somatosensory cortex of the brain.
