Cerebral Cortex Flashcards
Cortical cells
-contain glutamate
-are excitatory
-are projection neurons, and
their major axons enter the white matter
-The brain regions targeted by pyramidal cells are
based in part on their laminar position
Cortical: Cells in deep layers tend to project to ____
targets.
-subcortical
Layer 6 cells tend to project to the _____
:
-thalamus, mainly to specific relay nuclei.
Cortical: Cells in superficial layers tend to project to _____
-other cortical areas
Cortex: Both layers 2 and 3 have
_____projections (same hemisphere).
-associational
Which layer of cortical neurons are the main source of callosal axons that travel to the opposite hemisphere?
- Layer 3
Commissural projections are homotopic
if they innervate the same cytoarchitectonic division on the opposite side
Commissural projections are heterotopic
-if they innervate a different cortical division.
What correlates to the complexity of the computational processes carried out by pyramidal cells in particular regions and species?
-dendritic branching and spine density
stellate cell
- is the only known type of excitatory interneuron in the cortex
- It is a modified pyramidal cell that loses its extrinsic axon in the course of development
chandelier cell
- makes local connections
- synapses onto the axon initial segment of pyramidal cells
- most powerful of the interneurons
double bouquet cell
-gives rise to vertically directed axons that target the distal dendrites of pyramidal cells and non-pyramidal cells across multiple layers.
basket cells
-inhibitory interneurons whose axons spread horizontally and synapse onto the soma and proximal dendrites of pyramidal neurons in the same layer
where do most of the synapses on cortical pyramidal cells come from?
-neighboring stellate (+) cells and pyramidal neurons
where do most of the excitatory drive to basket cells arose from?
-intrinsically from pyramidal neurons
what role do basket cells play in the cortical connectivity
-basket cells inhibit other pyramidal neurons providing necessary connections for: feedback, feedforward, and lateral inhibition
what role do the double bouquet cells play?
- their activation is unknown
- they synapse onto distal dendrites of both pyramidal neurons and other interneurons
in sensory cortices, the major excitatory input is from
- specific thalamic nuclei
- these terminate in layer 4 on stellate or pyramidal cells with some sparse inputs to basket cells
cortico-cortico afferents
Ascending or feed forward projections generally originate in layer ___ and terminate in layer ___
-originate layers 2/3
terminate in layer 4
feedback projections generally originate in layers __ and terminate in layers __
- originate from layers 5/6
- terminate in layers 1 and 6
intralaminar thalamic afferents synapse primarily within layer __
-1
and they innervate the distal dendrites of pyramidal cells
intralaminar thalamic afferents
-increase the overall excitability of cortical neurons to promote a conscious state that is able to process information
cortical regulation of complex behaviors involves ____ pf separate stimulus features through ___ pathways
- parallel processing
- divergent
