Neurotransmitters and Sleep

Sleep is an active process, not just a default state when there is less incoming sensory information. It can be understood best by considering fluctuating levels of a series of neurotransmitters including the biogenic amines and acetylcholine. The effects of these neurotransmitters are not unique to sleep, but also subserve a wide range of other functions, including affect, sexual behavior, and appetite. The mechanism by which the most common hypnotics work is by binding to the benzodiazepine recognition site of the γ-aminobutyric acid_A-benzodiazepine receptor complex, which mediates action of the most widely distributed inhibitory neurotransmitter in the nervous system. It is possible that some endogenous sleep factors indirectly alter the properties of this receptor complex.