1f. Synaptic Processing

Question 1

Axon Hillock

Answer 1

Contains many Na+ channels, meaning the action potential threshold is lowest.

Therefore, action potentials initiate in the axon hillock first, no matter which part of the neurone is stimulated.

Question 2

3 Synapse Locations

Answer 2

Axo-somatic = on soma
Axo-dendritic = on dendrite
Axo-axonic = presynaptic synapse

Question 3

Dendritic Arithmetic

- 3 Types

Answer 3

Dendritic addition:
2 excitatory synapses on neighbouring dendrites

Dendritic subtraction:
Excitatory synapse on one dendrite and inhibitory synapse on a neighbouring dendrite

Dendritic division:
Excitatory synapse and inhibitory synapse on the same dendrite
- Shinting inhibition

Question 4

Presynaptic Inhibition

Answer 4

The results of depolarising Na+ conflict with hyper polarising Cl- and K+ are:

• Reduces action potential height
• Reduced Ca2+ current
• Reduced transmitter release