<prompt> Exocytic release of ACH is blocked by ?HemicholiumBotulinumAlpha bungarotoxindVesamicol  <response>: Ans. is b i.e., Botulinum ACETYLCHOLINE SYNTHESIS AND RELEASE Choline is actively taken up by the axonal membrane by Na; choline cotranspoer. Rate limiting step. This step is blocked by Hemicholinium. Choline is acetylated with the help of ATP and coenzyme A by the enzyme choline acetyl transferase present in the axoplasm. 