REM sleep deprivation induces subsensitivity of dopamine receptors mediating sedation in rats

REM sleep deprivation eliminates the sedative response to small doses of apomorphine (25–50 μg · kg−1) but does not prevent the inhibitory effect of apomorphine on dopamine (DA) synthesis. The results suggest that REM sleep deprivation may lead to the development of subsensitivity in DA receptors that mediate sedation and that these receptors are differentiated from those controlling DA synthesis. The relevance of this finding as a possible explanation of the mechanism of action of the antidepressant effect of REM sleep deprivation is discussed.