Synaptic Transmission

Question 1

Describe the events, starting with a pre synaptic AP that leads to either a post synaptic AP or EPSP/IPSP.

Answer 1

Presynaptic AP
Depolarisation of presynaptic terminal, 
opening of VOCC,
Ca++ entry and fusion of vesicles with membrane
Release of NT
Uptake/degradation/diffusion
Opening of Ach gated cation channel
Opening of Na, K chanels

AP if reach threshold

EPSP if depolarising but dont reach threshold
IPSP if hyperpolarising away from threshold

Question 2

What conditions would you want to be able to study quantal release of NT?

Answer 2

Low Ca++
High Mg++
Curare