PsychopharmacologyApril 25, 1979D Ruffing, B Kovacic, S Demetriou et al.
The narcotic antagonist naloxone was tested to determine its possible interaction with N,N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained to press a bar on a fixed-ratio four schedule (FR4), i.e., every fourth press earned a reward of 0.01 ml sugar sweetened milk. LSD (0.1 mg/kg) or increasing doses of DMT (1.0, 3.2, and 10.0 mg/kg) were...
Adult male Holtzman rats were trained to barpress on a schedule whereby every fourth press earned a reward of 0.01 ml of sugar-sweetened milk (FR4). After an i.p. injection of LSD (0.1 mg/kg) or DMT (3.2 or 10 mg/kg) such barpressing is abolished completely and resumed, usually within an hour, at a rate near the preinjection control rate of pressing. It continues at a steady, uninterrupted pace...