Single-trial conditioned place preference using intravenous morphine.
Experiments were performed to investigate single-trial conditioned place preference (CPP) using intravenous morphine in rats. Single-trial CPP was obtained when morphine (8 mg/kg) was paired for either 15 or 30 min with a distinct white compartment. When morphine administration was delayed for either 15 or 25 min after the beginning of a 30-min exposure to the white compartment, single-trial CPP was not obtained. Intravenous naloxone (2 mg/kg) also blocked single-trial CPP when administered 15 min after the beginning of the 30-min exposure to the white compartment with morphine, but naloxone by itself did not alter place preference. The results from these experiments indicate that single-trial CPP using intravenous morphine may offer a useful animal model to assess the reinforcing efficacy of the initial drug experience.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects*; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D009270:Naloxone; D009020:Morphine