1. Drugs that affect neuronal functioning by altering neuronal transmission in ways other than attaching to synaptic receptors.

2. Drug categories
Agonist - A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell
Antagonist - A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell

3. Type of Drug Action
Drug affects the amount of neurotransmitter stored in vesicles
If it facilitates storage (e.g., by acting as a precursor) -agonist
If it inhibits storage (e.g., by inhibiting synthesis of neurotransmitter or by blocking the storage into vesicles) - antagonist
Drug affects release of neurotransmitter
If it increases release - agonist
If it inhibits release -antagonist
Drug affects reuptake/breakdown of neurotransmitter
If it facilitates reuptake/breakdown - antagonist
If it inhibits reuptake/breakdown - agonist

4. Drug effects on Dopaminergic neurons
Effects on the amount of neurotransmitter stored in vesicles
L-DOPA facilitates synthesis of DA by acting as a precursor -agonist
Deprenyl facilitates synthesis of DA by blocking the enzyme MAO-agonist
Reserpine blocks the storage of DA into vesicles - antagonist
Effects on the release of neurotransmitters
Amphetamine increases release of DA- agonist
Effects on the reuptake of neurotransmitters
Cocaine and amphetamine blocks DA reuptake- agonist

5. Drug effects on Acetylcholinergic neurons
Effects on the amount of neurotransmitter stored in vesicles
Choline facilitates synthesis of ACh by acting as a precursor -agonist
Effects on the release of neurotransmitters
Botulinum toxin blocks the release of ACh - antagonist
Black widow spider venom facilitates the release of ACh - agonist
Effects on the breakdown of neurotransmitters
Physostigmine blocks ACh breakdown by inhibiting the enzyme Acetylcholinesterase- agonist

6. Drug effects on Serotonergic (5-HT) neurons
Effects on the amount of neurotransmitter stored in vesicles
PCPA inhibits synthesis of 5-HT - antagonist
Effects on the release of neurotransmitters
Fenfluramine facilitates the release of 5-HT - agonist
Effects on the reuptake of neurotransmitters
Fluoxetine (Prozac) blocks reuptake of 5-HT- agonist