Final answer:
Serotonin is the neurotransmitter that helps regulate mood.
Step-by-step explanation:
Serotonin is the neurotransmitter that helps regulate mood. It is often referred to as the "feel-good" neurotransmitter because it plays a key role in feelings of happiness and well-being. Serotonin is involved in various physiological processes, including sleep, appetite, and mood regulation.
Learn more about neurotransmitters