Which neurotransmitter is involved in arousal and sleep regulation?

The involvement of neurotransmitters in arousal and sleep regulation is complex, but serotonin plays a significant role in this process. Serotonin is primarily known for its influence on mood, but it also contributes to regulating circadian rhythms, influencing both wakefulness and sleep patterns. This neurotransmitter is synthesized in the brain and can affect wakefulness and transitions between sleep and wake states.

Research indicates that serotonin levels fluctuate during the sleep-wake cycle, with higher levels promoting wakefulness and decreasing levels associated with the onset of sleep. It is also a precursor for melatonin, which is directly involved in the sleep-wake cycle.

GABA, dopamine, and acetylcholine are all important neurotransmitters in various functions related to mood, cognition, and muscle activity, but they do not have the specific and directly established role in sleep regulation that serotonin does. Therefore, serotonin is identified as the key neurotransmitter associated with both arousal and sleep regulation in this context.