Cerebral cortex

Question 1

How many layers does the isocortex/neocortex have?

Answer 1

6 layers

Question 2

How many layers does the allocortex have?

Answer 2

3 layers. Includes paleocortex (olfactory) and archicortex (hippocampus)

Question 3

What is another name for layer 1, 2, 3?

Answer 3

Molecular layer
External granular layer
External pyramidal layer

Question 4

What is another name for layer 4? What is unique about layer 4?

Answer 4

Layer 4 has three divisions. It is called the internal granular layer

Question 5

What are the names of layers 5 and 6?

Answer 5

Internal pyramidal layer and fusiform layer.

Question 6

Which layers are in the supragranular layer?

Answer 6

1, 2, 3

Question 7

Which layers are in the granular layer?

Answer 7

4

Question 8

Which layers are in the infragranular layer?

Answer 8

5, 6

Question 9

What types of neurons will you find in the cortex?

Answer 9

Spiny stellate cells, pyramidal cells, nonpyramidal cells

Question 10

Where will you find the spiny stellate cells?

Answer 10

In layer 4

Question 11

what is unique about the dendrites of the spiny stellate cells?

Answer 11

They have spines

Question 12

Are spiny stellate cells excitatory or inhibitory?

Answer 12

excitatory

Question 13

Where do spiny stellate cells project information to?

Answer 13

Projects information vertically to layer 2/3

Question 14

What are the major dendrites of the pyramidal neurons? Where do they extend?

Answer 14

Apical dendrite extends to layer 1 and ends in the apical tuft
Oblique dendrites extend from apical shaft
Basal dendrites extend from Soma

Question 15

In which layers can you find pyramidal neuronal bodies?

Answer 15

2/3, 5, 6

Question 16

pyramidal neurons in Layer 6 go to:

Answer 16

thalamus

Question 17

pyramidal neurons in layer 5 go to:

Answer 17

Spinal cord, pons, medulla

Question 18

Pyramidal neurons in layer 2/3 go to:

Answer 18

Cortex/corpus callosum

Question 19

What neurotransmitter do pyramidal neurons respond to?

Answer 19

5-HT (serotonin). If they have 5-HT2 receptors, they are excitatory. If they are 5-HT1A receptors, they are inhibited by 5-HT

Question 20

Where can you find neocortical nonpyramidal neurons?

Answer 20

In ALL layers of the neocortex.

Question 21

What do neocortical nonpyramidal neurons use as a transmitter?

Answer 21

GABA

Question 22

How does feed forward inhibition work?

Answer 22

GABA neurons modulate the transmission of excitatory afferents to pyramid neurons

Question 23

How does feed-back inhibition work?

Answer 23

GABA neuron takes signal from pyramid neuron and feeds it back to the pyramid neuron to dampen excitement.

Question 24

What is excitotoxicity?

Answer 24

Too much excitation can injure or kill neurons.

Question 25

What type of information is conveyed by top-down versus bottom-up information in pyramidal neurons?

Answer 25

top-down=predictive information

bottom-up=perceptive infromation

Question 26

what happens when pyramidal cells receive both bottom up and top down signals?

Answer 26

Results in synergy with a large burst in activity. Thus, these bursts convey information about expectations matching perceptions

Question 27

How are neurons processing similar types of information arranged in the cerebral cortex?

Answer 27

They have a COLUMNAR STRUCTURE–vertical arrangements