Morphine withdrawal-facilitated aggression is attenuated by morphine-conditioned stimuli.
There is a considerable body of evidence indicating that stimuli associated with drug administration may become conditioned and evoke drug-like effects. The purpose of this study was to evaluate the ability of morphine-paired stimuli to affect an expression of morphine withdrawal-facilitated aggression. Individually housed aggressive adult mice were subjected to the repeated subcutaneous administration of morphine (twice a day, 8 days, increasing doses 10-80 mg/kg). Morphine treatment cessation facilitated an aggressive behaviour of animals during the second day of withdrawal. Subcutaneous but not intraperitoneal injection of saline attenuated the aggressive behaviour in morphine-withdrawn mice. These results suggest that the site of drug injection may serve as a conditioned stimulus.
Laboratory of Behavioural Pharmacology, Department of Psychopharmacology, Valdman Institute of Pharmacology, Pavlov Medical University, 6/8 Lev Tolstoy Street, St. Petersburg 197089, Russia. behav@spmu.rssi.ru
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Sukhotina
D000374:Aggression / Q000187:drug effects*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D003463:Cues; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D007398:Interpersonal Relations; D008297:Male; D051379:Mice; D009020:Morphine / Q000009:adverse effects* / Q000494:pharmacology*; D009294:Narcotics / Q000009:adverse effects* / Q000494:pharmacology*; D012934:Social Isolation; D013375:Substance Withdrawal Syndrome / Q000523:psychology*; D013997:Time Factors
D009294:Narcotics; D009020:Morphine