6-Hydroxydopamine and the aggressive behavior induced by marihuana in REM sleep-deprived rats

6-Hydroxydopamine (6OH-DA) pretreatment increased the aggressive behavior induced by marihuana in REM sleep-deprived rats. Brain catecholamine assays revealed that 6OH-DA depleted popamine (DA) and norepinephrine (NE) to a different extent, increasing the DA/NE ratio. Intraventricular injection of NE significantly decreased the aggressive behavior of these animals, whereas control solution or DA injections had no effect. The possible role played by DA and NE in the aggressive behavior induced by marihuana in REM sleep-deprived rats is discussed.