Modulation of Sleep-Wake Cycles in Mice and Rats with Cannabinoids

The main psychoactive ingredient of marijuana tetrahydrocannabinol ( THC) and endocannabinoids are involved in the modulation of the sleep-wake cycle. Systemic administration of the CB1 antagonist/inverse agonist SR141716A dose-dependently induced an increase in wakefulness and a reduction in slow wave sleep (SWS) and rapid eye movement (REM) sleep [1]. In keeping with this observation, intracerebroventricular [2] or direct administration of anandamide into the peduncle pontine tegmental nucleus and medial preoptic area [3], two regions involved in the regulation of REM and non-rapid eye movement (NREM) sleep, increased NREM and REM sleep and reduced wakefulness. This effect was reversed with SR141716A [3, 4] indicating that the effects on sleep are mediated by activation of CB1 receptors. However, the exact mechanisms by which cannabinoids modulate sleep-wake cycle are not fully understood.