The dopamine antagonist, alpha-flupenthixol, interferes with naloxone-induced place aversion learning, but not with acute opiate dependence in rats.
Pretreatment with the dopamine antagonist alpha-flupenthixol (alpha-flu) interfered with the establishment of a naloxone-induced place aversion in two experiments. In Experiment 1, the potential of pretreatment with alpha-flu to interfere with the establishment of a naloxone-induced place aversion was evaluated in rats administered morphine (Group MN) or saline (Group SN) 24 h prior to the naloxone conditioning trial. Naloxone-precipitated withdrawal from morphine administered 24 h prior to the trial produced a stronger place aversion than produced by naloxone alone. The neuroleptic, alpha-flu, attenuated the naloxone-induced place aversion, but did not selectively interfere with the place aversion produced by acute opiate dependence. Experiment 2 replicated demonstration of interference with naloxone-place aversion learning by neuroleptic pretreatment with the inclusion of saline controls. These results suggest that dopamine modulates either the aversive motivational properties of naloxone or learning, even in opiate naïve rats.
Santi
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Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada N2L 3C5.
Parker
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LA
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D018492:Dopamine Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D005475:Flupenthixol / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009293:Opioid-Related Disorders / Q000188:drug therapy; D051381:Rats; D017207:Rats, Sprague-Dawley
D018492:Dopamine Antagonists; D009292:Narcotic Antagonists; D009270:Naloxone; D005475:Flupenthixol