Comparative effects of tetrahydrocannabinol on psychostimulant-induced behaviors.
The behavioral effects of delta-9-tetrahydrocannabinol (THC), one of the major psychoactive cannabinoids in marijuana, were tested in two models of psychostimulant-induced behaviors in rats (locomotor behavior and stereotyped gnawing) induced by amphetamine (AMPH) and methylphenidate (MEPH). Pretreatment with THC (10 mg/kg gavage) almost doubled the amount of AMPH-induced gnawing but produced no effect on AMPH-induced locomotor behavior. In contrast to AMPH, THC produced no direct effect on MEPH-induced gnawing but caused a strong suppression of MEPH-induced locomotor activity. In addition, there was no additional interaction between THC and reserpine as measured by suppression of MEPH-induced gnawing. This result was unexpected in view of the powerful interaction between THC and reserpine reported previously. Because of the clear THC-induced dissociation of the behavioral effects of these two psychostimulants (AMPH and MEPH), our working hypothesis is that THC affects motor behaviors by some non-dopaminergic mechanism.
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D013759:Dronabinol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000494:pharmacology; D013239:Stereotyped Behavior / Q000187:drug effects
D000697:Central Nervous System Stimulants; D008774:Methylphenidate; D013759:Dronabinol; D012110:Reserpine; D000661:Amphetamine