Cerebral Cortex Flashcards
(26 cards)
The supragranular layer of the cerebral cortex refers to layers ____?
Layers 1-3
The granular layer of the cerebral cortex refers to layers ____?
Layer 4
The infragranular layer of the cerebral cortex refers to layers ____?
Layers 5-6
In which layer of the cerebral cortex are you most likely to find a spiny stellate cell body?
Layer 4
In what layer(s) of the cerebral cortex are you most likely to find the dendrites of a spiny stellate cell?
Layer 4
Are spiny stellate cells excitatory or inhibitory? What neurotransmitter do they release?
Excitatory; Glutamate
In which direction do spiny stellate cell axons project?
Up, mostly to layers 2/3
Where do spiny stellate cells receive input from?
Thalamus and cortex; considered the thalamocortical relay cells but the bulk of their input is from other cortical cells
Which neuronal cells type is the most numerous in the cortex?
Pyramidal
Are cortical pyramidal cells excitatory or inhibitory? What neurotransmitter do they release?
Excitatory; Glutamate
In which direction do pyramidal axons project?
Down, final destination largely dependent on cortical layer cell body is found in
Layer ____ pyramidal cells are the primary output for the cerebral cortex.
Layer 5
Where to layer 5 pyramidal cell axons project to?
To the spinal cord and brainstem
Where do layer 6 pyramidal cell axons project to?
To the thalamus and collosum
Where is the apical tuft region of layer 6 pyramidal cells?
Layer 4
Where are the excitatory inputs received on pyramidal cells? What is special about these input locations?
Excitatory inputs received on dendritic spines; these spines are highly dynamic due to actin polymerization which allows constant remodeling of connectivity
Do nonpyramidal cortical neurons have spines?
No, nonpyramidal cortical neurons do not have spines
What type of cell bodies are found in layer one of the cerebral cortex?
Nonpyramidal
Are nonpyramidal neurons excitatory or inhibitory? What type of neurotransmitter do they release?
Inhibitory; GABA
Describe the process of feed-forward inhibition.
Nonpyramidal GABAergic neurons that are excited by afferent input then inhibit nearby neurons that receive the same excitatory afferent input
Describe the process of feedback inhibition
Nonpyramidal GABAergic neurons that are excited by afferent input reciprocally inhibit the excitatory afferent neuron
What are the 5 steps in a cortical circuit?
- Thalamic input to layer 4 spiny stellate cells
- Spiny stellate cell axons synapse on layer 2/3 pyramidal neuron
- Layer 2/3 pyramidal neuron have extensive excitatory connectivity but ultimately synapse with layer 5 pyramidal neuron
- Layer 5/6 pyramidal neuron are output of the cerebral cortex to the spinal cord/brainstem/thalamus
- Feed-forward/feedback inhibition shapes the flow of excitatory activity
Basal dendrites of cortical pyramidal cells are located in layer ____ and receive ____ type of input.
Layer 5; Receive bottom up (perceptive) input
Apical dendrites of cortical pyramidal cells are located in layer ____ and receive ____ type of input.
Layer 1; Receive top down (predictive) input
