ACETYLCHOLINE

Hemicholinium

INHIBITION: inhibits ChT1 = prevent uptake of choline and synthesis of ACh

Triethylcholine

INHIBITION: Competes with choline for ChAT → forms acetytriethylcholine, a false transmitter

Vesamicol

INHIBITION: Reversible non-competitive inhibitor of VAChT = reduces acetylcholine pool in vesicle

Botulinum toxin

INHIBITION: light chain cleaves SNARE proteins

β-bungarotoxin

INHIBITION: Activates phospholipase A2 → phospholipids in active zone degraded → inhibits Ach release

α-latrotoxin

STIMULATION: Triggers massive ACh release through what is thought to be the formation of Ca2+ permeable channels

tetanus toxin

STIMULATION: Cleaves synaptobrevin and impairs inhibitory glycine release from inhibitory interneurones → over release of ACh → tetanic contractions