Which neurotransmitter enables learning and memory and also triggers muscle contraction?

• A. Endorphins
• B. Acetylcholine
• C. GABA
• D. Dopamine

Answer: (B)

Learning and memory rely on acetylcholine in brain circuits like the hippocampus, where it helps form and retrieve memories. At the same time, acetylcholine is the messenger at the neuromuscular junction that causes skeletal muscles to contract. That combination—supporting learning and memory in the brain and directly triggering muscle contraction—makes acetylcholine the best answer.

Endorphins mainly affect pain and mood; GABA is the brain’s primary inhibitory transmitter; dopamine influences reward and certain aspects of movement, but neither directly accounts for both learning/memory and muscle contraction.