Which neurotransmitter is involved in alertness and arousal?

Norepinephrine is the neurotransmitter primarily associated with alertness and arousal. It plays a critical role in the body’s stress response, often referred to as the "fight or flight" response. When norepinephrine is released, it increases arousal and alertness, enhances attention, and prepares the body for action. This neurotransmitter is found in various parts of the brain, where it influences mood and energy levels, providing the necessary stimulation for increased alertness.

In contrast, serotonin is more significantly linked to mood regulation and feelings of well-being rather than direct involvement in alertness. Dopamine is involved in motivation, pleasure, and reward-seeking behaviors but is not primarily responsible for alertness. Acetylcholine plays a role in learning and memory and also contributes to arousal but to a lesser extent than norepinephrine. Therefore, norepinephrine stands out as the key neurotransmitter in promoting both alertness and arousal.