6: Central Vision

Question 1

What is the Effect of a Dark Surround in an On-Center RGC?

Answer 1

When the Surround is in the Dark…

• Surround cones depolarize
• Surround cones release gluta onto horizontal cells
• Horizontal cells depolarize
• Horizontal cells release GABA onto the center cone
• Center cone hyperpolarizes even more
• -Similar to if it had gotten more light!

Question 2

Explain Layer 1 of V1.

Answer 2

• Lots of synapses
• No cell bodies
• No specialized identifiable function
• Lots of collaterals
• Pyramidal cell dendrites

Question 3

Explain Layer 2/ 3 of V1.

Answer 3

-Send/ receives axons to/ from other cortical areas (including opposite hemispheres)

Question 4

Explain Layer 4 of V1.

Answer 4

• Main input layer where thalamic axons terminate/ synapse
• -Receives thal axons
• -Highest density of stellate neurons

Question 5

Explain Layer 5 of V1.

Answer 5

• Syn on neurs in spin cord which sends musc sigs/ neurons that cause movement
• Sends axons to brainstem & spinal cord

Question 6

Explain Layer 6 of V1

Answer 6

-Efferent axons to thal