Lecture 36- Cortex 1 Flashcards
What is another name for the lateral sulcus?
sylvian fissure
What is the defining feature of a neocortex?
it has 6 layers
What is the defining feature of an allocortex?
it has less than 6 layers
Where can allocortex be found?
limbic areas- hippocampus, entorhinal area etc
What is the principal cell in the cerebral cortex?
pyramidal cell
Is the pyramidal cell excitatory or inhibitory? What neurotransmitter does it produce?
excitatory, produces glutamate
In what layers of the cortex would the pyramidal cells be found?
Layers 2,3 and 5,6 (layer 1 is mostly acellular and layer 4 is spiny stellated)
Where does the apical dendrite of the pyramidal cell project?
to the pial surface (layer 1)
Where does the axon of the pyramidal cell project?
down towards the white matter
What is special about the apical dendrite and basal dendrites of the pyramidal cell?
they are covered with spines
What is the name given to the cells in layer 4 of the cortex that look similar to pyramidal cells but lack an apical dendrite?
spiny stellate cells
What layer of the cortex houses spiny stellate cells?
layer 4
What differentiates spiny stellate cells from pyramidal neurons?
spiny stellate cells are lacking an apical dendrite
Are spiny stellate cells excitatory or inhibitory?
excitatory-gluatamate-dendritic spines
Are chandelier and basket cells excitatory or inhibitory?
GABAergic-inhibitory
Where do basket cells synapse on the pyramidal neuron?
cell body
What is contained within layer 1 of the cerebral cortex?
layer 1- molecular layer- mostly acellular- contains apical tufts of pyramidal neurons (from 2,3 and 5,6)
What is found in layers 2,3 of the cerebral cortex?
small and medium pyramidal cells that project locally
What is found in layer 4 of the cortex?
spiny stellate cells that receive input from the thalamus
What layers receive input from the thalamus?
Primarily layer 4 with some collateral to layers 3 and 6
What defines a granular cortex?
prominent layer 4 (ex. Somatosensory cortex)
What defines an agranular cortex?
lacking a prominent layer 4 (ex. primary motor cortex)
Where are Betz cells found?
Layer 5 of the the primary motor cortex (they form the corticobulbar tracts)
Where do the axons that form the corticobulbar tract originate?
Layer 5 Betz Cells of the primary motor cortex
What does the weigert stain do?
stains myelin bundles
What is Brodmann’s area 4?
primary motor cortex
What is the Brodmann’s area for the primary motor cortex?
4
What is Brodmann’s area 17?
primary visual cortex
What is Brodmann’s area 41 and 42?
auditory cortex
What is Brodmann’s area 1,2,3?
Somatosensory cortex
Where does thalamic input to the cortex terminate?
Layers 4, 3, 6
Where does callosal (between hemispheres) input terminate in the cerebral cortex?
Layer 3
Where do projects from layer 5 go?
subcortical areas (ex. superior colliculus)
Which layer of the cerebral cortex projects to subcortical structures like the superior colliculus?
layer 5
Which layer of the cerebral cortex projects back to the thalamus to provide feedback?
layer 6
Where do axons from layer 6 project to?
thalamus
In what layer of the striate cortex is the Stripe of Gennari found?
Layer 4B
Where do chandelier cells synapse on pyramidal cells?
axon initial segment
