Cortical Structure and Function.

Question 1

Cortex can be split into what? What proportion of the brain is each part?

Answer 1

Neocortex (90%) and Allocortex (10%).

Question 2

How many layers does the Neocortex and Allocortex have respectively?

Answer 2

6,3.

Question 3

What can the allocortex be split into?

Answer 3

Palleocortex (olfactory cortex) and Archiocortex (hippocampal cortex).

Question 4

What are the 6 layers of the neocortex and how can these 6 layers be grouped?

Answer 4

(1) Molecular layer, (2)external granular, (3)external pyramidal - supra-granula.
(4) Internal granular - Granular.
(5) Internal pyramidal and (6)multiform - Intragranular.

Question 5

Which out of the 6 layers is the input and which is the output?

Answer 5

Layer 4 - internal granular is the input. Contains most of the pyramidal cells = densest.
Layer 5 - internal pyramidal is the output.

Question 6

Pyramidal cells are what % of the cortex?

Answer 6

75-85%.

Question 7

What other structures are pyramidal cells located?

Answer 7

Hippocampus and amygdala.

Question 8

Are pyramidal cells excitatory or inhibitory?

Answer 8

Excitatory.

Question 9

Granule cells are found in the cortex and where else?

Answer 9

Hippocampus and cerebellum.

Question 10

Are granule cells inhibitory or excitatory?

Answer 10

GABAergic - inhibitory.

Question 11

What are the 3 Cortical fibre afferent pathways, describe each.

Answer 11

Association, layers 1-3. Commissural, found in the corpus callosum and thalamocortical fibres, synapse with layer 5 pyramidal cells.