Cerebral Cortex

Question 1

Allocortex

Answer 1

Hippocampus and parahippocampal cortex

Question 2

Isocortex

Answer 2

The neocortex

Question 3

Where does the neocortex receive afferents from?

Answer 3

Thalamus
Neocortex
Extrathalamic subcortical (monoamines and cholinergic projections from brainstem)
Amygdala (confers emotional tone to neocortical areas)
Parahippocampal areas, role in memory

Question 4

Major neocortical efferents

Answer 4

Thalamus (reciprocal projections from layer 6)
Neocortex
Amygdala
Parahippocampal gyrus
Basal Ganglia (NOT reciprocal)
Projections to downstream areas of motor cortex

Question 5

How many layers of neocortex?

Answer 5

6

Question 6

Explain regional specialization of the neocortical layers

Answer 6

Depending on the area of the brain, the layers are thicker/thinner. For example V1 has big layer IV (where thalamus inputs). Motor cortex has big layer V.

Question 7

Where is the macula represented?

Answer 7

At the very posterior portion of V1

Question 8

Pyramidal neurons

Answer 8

Principal output neurons, main axon leaves the cortex, spiny and excitatory (glu)

Question 9

Non-pyramidal neurons

Answer 9

Interneurons with local projections. Some are inhibitory (GABA) some are excitatory (spiny stellate)

Question 10

Major subtypes of GABAergic interneurons and where they contact pyramidal cells

Answer 10

Chandelier Cell (at axon inital segment) , Double Bouquet (At dendritic shafts and spines), Basket Cells (at cell bodies)

Question 11

Cell type implicated in epilepsy?

Answer 11

Large Basket cell

Question 12

Function of the monoaminergic projections from brainstem?

Answer 12

Attention, mood, affective state, sleep, vigilance

Question 13

Function of the cholinergic projections from the nucleus basilis?

Answer 13

Cognition and learning/memory

Question 14

Type of circuit with

1) gaba
2) glu
3) monoamines

Answer 14

1) local interneurons
2) cortical-cortical, thalamo cortical
3) diffuse modulatory control from brainstem to cortex

Question 15

Two streams of vision

Answer 15

What (inferotemporal stream) V1-> V2 -> V4 ->Temporal. Cells selective for pattern and shape.
Where (parietal stream), cells selective for motion, rotation, etc.

Question 16

Face recognition

Answer 16

Fusiform gyrus

Question 17

Visual agnosia

Answer 17

non-aphasic person can’t recognize a stimulus, even though they can’t see it

Question 18

Prosopagnosia

Answer 18

Can;t recognize faces. Correlated with damage to occipitotemporal area

Question 19

Visual object agnosia

Answer 19

Inability to recognize general classes of objects

Question 20

Balint’s syndrome

Answer 20

Optic ataxia (can’t target point given visual guidance), ocular ataxia (inability to shift gaze at will towards new stimuli), simultanagnosia (perception and recognition of only parts of the visual field)

Question 21

Function of the pre-frontal cortex

Answer 21

Working memory, planning, executive function, top-down cognitive control, modifying the rules, response inhibition

Question 22

Convergence of modalities in the prefrontal cortex

Answer 22

Input from auditory/somatosensory/motor/visual/medial temporal structures, then integrated by the PFC

Question 23

Cognitive test for DLPFC

Answer 23

Delayed response test, neurons from PFC fire during the delay signifying that thinking is occuring. Also, neurons fire in the region of the brain that control either where or what.

Question 24

Where does activity migrate after DLPFC and visual cortex active?

Answer 24

Migrates back to premotor cortex, and along the what/where streams

Question 25

What happens in auditory delay test?

Answer 25

PFC active, and Heschel’s active

Question 26

What is organized pre and post central sulcus

Answer 26

Pre: executive/motor

Post is sensory/perceptual

Question 27

Where are “Rules of the Game” encoded?

Answer 27

PFC

Question 28

Wisconsin card sorting

Answer 28

Patients with damage to PFC can’t change the rules.