Role of Neurotransmitters in Regulating Sleep And Awake Cycle : A Review

During sleep, a person does not response to the surrounding environment. Sleep disorders affect personal life of the individuals. In brain,various neurotransmitters are responsible for the sleep and wake cycle. Acetylcholine, serotonin, dopamine, histamine and orexin promote wakefulness while GABA neurotransmitters promote sleep. Two subtypes of histamine are involved in sleep/wake cycle. Histamine release is decreased by the activation of H3 receptor which encourages sleep, while H1 receptor promotes wakefulness.Dopamine D2 receptors are responsible for controlling sleep/wake cycle. It is still not completely understood about which serotonin subtype is involved in controlling sleep/wake pattern. GABA neurons are present in preoptic area and basal forebrain and their release become increase during sleep. GABA neurotransmitters are divided into three subclasses e.g. GABAA, GABAB and GABAC. GABAA and GABAC neurotransmitters produce their effects by inhibiting Cl ion channels. GABAC neurons are mainly located in retina while GABAA neurons are located throughout the brain. GABAB neurons produce their effects by inhibiting Ca 2+ in the presynaptic vesiclesand these neurons are located in spines.