MCQ Physiology Answer 8

Synthesis of ACh requires the uptake into the nerve terminal of choline. Hemicholinium-3 inhibits the plasma membrane pump for choline. In the absence of choline uptake, cholinergic nerves eventually become depleted of ACh. The more cholinergic nerves are stimulated in the presence of HC-3, the more rapidly they fail.

Storage of ACh in synaptic vesicles requires its uptake into synaptic vesicles. Vesamicol is a drug that prevents the uptake pump for ACh in synaptic vesicles. Similar to the effects of HC-3, once a cholinergic nerve is depleted of preformed ACh, then transmission fails.

The release of synaptic vesicles from cholinergic nerve terminals is blocked by botulinus toxin (Botox®). This effect is useful both experimentally and clinically.

Category: Physiology MCQs