Acetylcholine That Has Been Released into the Synaptic Cleft Is

Question

Acetylcholine that has been released into the synaptic cleft is rapidly inactivated by
A)sucrase.
B)active transport into the sarcoplasmic reticulum.
C)acetylcholinesterase.
D)monoamine oxidase.
E)diffusion out of the synaptic cleft.

Accepted Answer

Acetylcholine that has been released into the synaptic cleft is rapidly inactivated by acetylcholinesterase. This enzyme breaks down acetylcholine into choline and acetate, which are taken back up by the presynaptic terminal and used to synthesize new acetylcholine. This process ensures that the neurotransmitter is only active for the necessary amount of time, and also prevents excessive activation of the postsynaptic neuron.