Question

If an AChE inhibitor were added to a cholinergic synapse, the expected effect on synaptic transmission would be

A. decreased response in the postsynaptic cell.

B. increased ACh affinity for the receptors.

C. increased ACh released from the presynaptic cell.

D. decreased reuptake of ACh.

E. increased ACh available for binding in the synaptic cleft.

A researcher studying neurotransmitter release changes the solution surrounding neurons from normal saline to Ca2+ free saline. This change would result in

A. decreased transmitter release

B. decreased depolarization

C. increased SNARE expression

D. increased synaptotagmin activity

E. decreased vesicle formation

Answer 1

Ans. (E) increased ACh available for binding in the synaptic cleft.

Explanation: AChE means acetylcholinestease. It is an enzyme that breaks down neurotransmitter acetylcholine. If an AChE inhibitor is added , then the action of the enzyme acetylcholinesterase would be inhibited and hence there will be no breakdown of neurotransmitter acetylcholine and increase ACh availibility and increase duration of neurotransmitter action.

Ans. (A) decrease transmitter release

Explanation: Ca²⁺ is required for the release of neurotransmitter and hence if Ca²⁺ is not available there will be decrease in release of neurotransmitter.