Exposure to self-administered drugs is sufficient to produce drug-seeking in animal models. In many cases priming injections of drugs that share discriminative stimulus properties with the self-administered drug also can lead to drug-seeking, suggesting that exposure might precipitate relapse. The present investigation examined the ability of MDMA or cocaine priming injections to reinstate...
There has been some controversy in the literature concerning the ability of +/-3,4 methylenedioxymethamphetamine (MDMA) to reinforce operant responding in rats. In the present study, operant responding maintained by intravenous MDMA infusions increased when the fixed ratio schedule was increased from 1 to 5, decreased when saline was substituted for MDMA, and increased again when MDMA was...