Synaptic Transmission: Targets of Drug Action

Question 1

Steps in neurotransmission

Answer 1

1. Neurotransmitter synthesis
2. Vesicular Storage
3. Synaptic Release
4. Binding to receptor
5. Termination of transmission

Question 2

Neurotransmitter synthesis

Answer 2

Requires:

• Precursors*
• Transport into the cell
• Enzymatic action*

Question 3

Vesicular Storage

Answer 3

NT stored in vesicles

Vesicular transport inhibition leads to NT depletion

Question 4

Synaptic release

Answer 4

AP propagated to terminal*
Opens calcium channels
Fusion of vesicle with membrane*

Question 5

Indirect acting drugs

Answer 5

Facilitate the increase of a NT in synapse
Ex: Amphetamine, phosphorylates reuptake transporters and inhibits vesicular uptake proteins. Increases amount of endogenous cytosolic NT and reverses the transporter resulting in excess NT being spewed into the synapse