Motivation of heroin-seeking elicited by drug-associated cues is related to total amount of heroin exposure during self-administration in rats.

摘要: Conditioned stimuli (CSs) previously associated with heroin are critically involved in activating long-lasting relapse and compulsive drug seeking. This study examined the magnitude of seeking induced by drug-related cues relation to total amount exposure during training. Five groups male Sprague-Dawley rats (n=6/group) were trained nose-poking response self-administer different doses (0, 0.01, 0.025, 0.05, 0.1 mg/kg per infusion respectively, one 4-h session daily, limited 25 infusions session) under an identical progressive ratio schedule gradual incremental requirements. All established stable self-administration within 14 days training, time needed obtain all decreased across sessions. After abstinence, elicited contextual (self-administration chamber) or discrete contingent CSs was measured two consecutive 1-h test phases. During both phases, even at lowest dose (0.01 mg/kg) showed higher active responses than saline controls, also 0.10 comparison those a 0.01 mg/kg. There no observable dose-dependence increase above 0.025 The results suggested that increased motivation seek is intake.