Cortex

Question 1

What are the 3 main areas of the auditory cortex?

Answer 1

Core
Belt
Parabelt

Question 2

How many layers does the auditory cortex have? Is this the same or different as other cortical sensory processing centers?

Answer 2

6 layers

A1 is similar?

Question 3

MGB projects mainly to what layer of the auditory cortex?

Answer 3

Layer IV

Question 4

Explain the neural connections in layer IV.

Answer 4

Layer IV is highly organized in vertical columns and has direct soma-to-soma contacts

Question 5

Explain the tonotopic organization of A1 and A2.

Answer 5

A1-some single cells are sharply tuned to a CF, tonotopic organization and iso-frequency strips
A2-poor tonotopicity and cells in the same region can have various CF

HF located dorsally and LF ventrally

Question 6

What are two things that make measuring response properties and classification very difficult in A1.

Answer 6

Responses are too diverse.

Only 66% of A1 neurons respond to sound (anaesthetized)

Question 7

Design a neuron with convergent inputs that has improved tuning.

Answer 7

Make neuron 1 and 3 inhibit neuron 4. Neuron 2 excites 4, so 4 is tuned to same frequency as 2. The inhibition from those 2 sides make tuning more narrow (inhibition good for tuning)

“You need 1 excitatory input and 2 inhibitory input”