how many layers does the neocortex contain?
how much of the cerebral cortex does the neocortex compose?
what are all the types of cells we can find in the different layers of the cortex?
- stellate cells
- fusiform cells
- horizontal cells
- cells of martinotti
- betz cells
what are the layers of the neocortex?
- Molecular layer
- External granule layer
- External pyramidal layer
- Internal granule layer
- Internal pyramidal layer
- Multiform layer
what does the molecular layer do?
has non-specific afferents from intralaminar nucleus of thalamus and brainstem
what does the external granule layer do?
receives callosal and association afferents
what does the external pyramidal layer do?
is where association and commisural fibers originate
what does the internal granule layer do?
receives afferents from thalamic nuclei
(is the termination point of thalamic relay neurons (VPL/VPM for post-central gyrus and LGN for visual cortex)
what does the internal pyramidal layer do?
is where the corticospinal, corticobulbar and corticostriatal originate
what does the multiform layer do?
gives rise to association and commisural fibers as well as corticothalamic fibers
what composes the other 10% of the cortex?
what are the 2 layers of the allocortex?
what part are these layers associated with?
1) Paleocortex: the olfactory system
2) archicortex: hippocampus
identify each layer
what cell do we find in the molecular layer?
what do they do?
help connect the cortical columns
what cells do we find in the deepest layer of the cortex?
what cells do we find in the external granule layer?
what is special about this cell?
stellate cells (granule cells)
is the main interneuron of the cortex
What cells do we find in the motor cortex only?
what are they?
huge pyramidal cells
What are the types of regions found in the neocortex?
granular regions and agranular regions
what do we find in the granular layer?
what do we find in the agranular layer?
large granular layers with smaller pyramidal layer
large pyramidal layer with smaller granular layer
what is the largest area of the cortex?
what is the smallest?
the motor cortex
the visual cortex
how is the cortex arranged? and how are they linked?
what is important to remember of way the cortex is arranged?
in vertical columns of 300-500 neurons and are linked using horizontal cells
vertical columns are the functional units of the cortex