Which neurotransmitter is NOT listed as stimulated by nicotine in the notes?

• A. Dopamine
• B. Norepinephrine
• C. Acetylcholine
• D. Histamine

Answer: (D)

Nicotine works by activating nicotinic acetylcholine receptors throughout the brain and autonomic nervous system. When these receptors are stimulated, several neurotransmitters are released. Dopamine is a key player in the brain’s reward pathway, helping drive the addictive effects. Norepinephrine is released as well, contributing to increased alertness and arousal. Acetylcholine signaling is amplified because nicotine directly stimulates the same receptor system that acetylcholine normally uses. While other transmitters can be involved downstream, the notes typically highlight dopamine, norepinephrine, and acetylcholine as being stimulated by nicotine. Histamine, although important in other physiological roles, isn’t usually listed as a primary transmitter stimulated by nicotine in those notes, making it the correct choice.