Synaptic Transmission

Question 1

Define electircal neuro transmission

Answer 1

Fast
Uses gap junction (directly connected to post synapse)
Multi directional

Question 2

Define chemical neuroxmission

Answer 2

Slow
Uses synaptic gap (physical space between pre and post synaptic clefts)
Uni-directional

Question 3

Steps in chemical synapse events

Answer 3

1. Neuron syn. NT in pre-synapse
2. NT stored in axon terminal
3. AP triggers release of Nt through opening of Ca channels
4. NT released from vesicle at pre-synaptic cleft to travel to receptors
5. Post-synapse changes in membrane potential and a response is illicited
6. NTs are reuptaked and taken away

Question 4

Where do NT’s come from

Answer 4

The food we eat

Question 5

NT’s must be what

Answer 5

Ca dependent

Able to be inactivated

Question 6

What happens with a EPSP

Answer 6

K out
Na in
More + cell
Easier to depol

Question 7

What happens with IPSP

Answer 7

K out OR (-) in (Cl)
Cell is more (-)
Harder to depol

Question 8

Define spacial summation

Answer 8

Increased number of pre-synaptic xmitters

Only fires on one post-synaptic neuron at the same time

Question 9

Define temporal summation

Answer 9

1 presynaptic neuron
Only fires on 1 post synaptic neuron

Takes a while and multiple transmissions to reach threshold

Question 10

What does a nAChR do (ionotropic)

Answer 10

ACh binds
Increase in Na and K permeability
Membrane depol.
AP made

Question 11

What does mAChR do

Answer 11

Uses GPCR

Releases a-GTP subunit

B and G illicit a variety of responses

Example: PNS