The aversive properties of acute morphine dependence persist 48 h after a single exposure to morphine: evaluation by taste and place conditioning.
The aversive properties of naloxone-precipitated morphine withdrawal from acutely administered morphine were assessed following a single conditioning trial using both the place conditioning and the taste conditioning paradigm. In both paradigms, the aversive properties of naloxone-precipitated morphine withdrawal were evident up to 48 h after a single injection of morphine. In neither paradigm did naloxone treatment alone produce an aversion after a single conditioning trial. These results suggest that a single morphine exposure produces long-lasting effects that persist at least 48 h beyond the agonist effects of the opiate.
Parker
Linda A
LA
Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada N2L 3C5. lparker@wlu.ca
Cyr
Joan A
JA
Santi
Andrea N
AN
Burton
Page D
PD
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D009021:Morphine Dependence; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013649:Taste / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
D009270:Naloxone; D009020:Morphine