Components of a circuit

Question 1

What is the difference between granular and agranular cortex.

Answer 1

Granular cortex has prominent layer IV while granular does not

Question 2

Describe the term cortical column [4]

Answer 2

• fundamental unit of computation
• 400 microns in diameter
• neurones differentially distributed across layers of cortical column
• creates distinctive layers (density, type, proportion of neurones)

Question 3

Describe the rodent barrel cortex [3]

Answer 3

• sensory input from individual whisker mapped to single cortical column in contralateral barrel cortex
• two thalamic inputs relayed into barrels cortex
• sensory input from each whisker mapped to individual cortical columns

Question 4

Describe layer IV [3]

Answer 4

• stellate cells (stark like)
• smaller
• excitatory neurones

Question 5

Describe hippocampal circuitry

Answer 5

• Input from entorhinal cortex
• to dentate gyrus
• to CA3
• to CA1
• output to subiculum and EC
• EC also directly to CA1

Question 6

Describe the perforant pathway

Answer 6

EC to dentate gyrus

Question 7

Describe mossy fibres

Answer 7

from DG to CA3

Question 8

Schaffer collateral

Answer 8

dentate gyrus to CA1

Question 9

temporoammonic pathway

Answer 9

EC directly to CA1

Question 10

Describe the hippocampal architecture

Answer 10

• Cornu ammonis subfields contain layer of pyramidal neurones (stratum pyramidale)
• inputs onto dendrites of CA1 pyramidal neurones in SP organised across layers

Question 11

Identify whats in which inhibitory interneurones can be classified [5]

Answer 11

• electrophysiological/firing properties
• morphology
• location
• embryonic origin
• axonal projections/ post synaptic targets

Question 12

Describe periosomtic-targeting neurones (example) [4]

Answer 12

• synapse with soma/axon initial segment of pyramidal neurones
• tight control over whether pyramidal neurones fires
• cell body on edge of SO and SP to edge of SR
• e.g. fast spring basket cells

Question 13

Dendrite-targeting neurones (example) [4]

Answer 13

• synapse onto apical/basal pyramidal cell
• plays role in controlling e which excitatory inputs onto pyramidal cell
• axon through SO and SR
• bi stratified cell

Question 14

Interneruon targeting neurone (example) [3]

Answer 14

• inhibit other interneurone
• mediate disinhibition
• VIP+

Question 15

PV+ internueones (example) [4]

Answer 15

• fast spiking periosomatic-targeting interneurones
• play role in generating rhythmic network activity
• in cortex and hippocampus
• PV basket cells/ axo-axonic cells/ chandelier cells

Question 16

Somatostatin (example) [4]

Answer 16

• found in dendrite-targeting cells
• deeper layers
• regular intervals between consecutive spikes
• hippocampus and cortex
• O-LM/ martonotti

Question 17

What is calbindin

Answer 17

calcium binding protein