Behavioral properties of psychoactive phenylisopropylamines in rats

Rats were trained to discriminate injections of 5-methoxy-N,N-dimethyltryptamine (5-OMe DMT, 3.0 mg/kg) a hallucinogenic agent for which a serotonergic mechanism has been implicated, from saline in a two-lever drug discrimination task. After reliable levels of accuracy (greater than or equal to 85%) were attained, the ability of the 5-OMe DMT cue to generalize to 36 substituted phenylisopropylamines (or their optical isomers) was assessed. The results reveal that, in general, the challenge compounds could be differentiated into three broad categories: Those that produced 5-OMe DMT-appropriate responding (generalization), those that produced partial 5-OMe DMT-appropriate responding (partial generalization) and those that produced negligible 5-OMe DMT-appropriate responding. It is concluded that certain of the substituted phenylisopropylamines, unlike amphetamine itself, can produce effects in rats similar to those produced by the training dose of 5-OMe DMT, and that a serotonergic mechanism might be involved.