title: Morphine-induced attenuation of morphine tolerance.
abstract: Rats experienced both morphine and an environmental cue, but the cue always signaled a drug-free period. They were subsequently administered morphine in the presence of the cue, and the development of analgesic tolerance was assessed. The prior experience retarded such tolerance. The finding that a procedure of opiate administration can retard opiate tolerance suggests that an association between cues preceding the drug and the drug itself contributes to tolerance.
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004361:Drug Tolerance; D008027:Light; D009020:Morphine / Q000494:pharmacology*; D051381:Rats
chemical_list: D009020:Morphine