Role of D-1 and D-2 receptor stimulation in sensitization to amphetamine-induced circling behavior and in expression and extinction of the Pavlovian conditioned response.
Circling behavior was measured in female rats treated with amphetamine (1.25 mg/kg d-amphetamine sulfate, IP) on 3 consecutive days. On days 4 and 5 saline was substituted for amphetamine. While the amphetamine-induced response was attenuated by both a D-1 (SCH 23390) and a D-2 (metoclopramide) antagonist. sensitization to amphetamine was attenuated by the D-1 antagonist only. In addition, expression of a placebo-like response observed on day 4 (characterized previously as a Pavlovian conditioned response) was attenuated by both the D-1 and D-2 antagonists without disrupting extinction of the response.
Department of Pharmacology and Toxicology, Albany Medical College, NY 12208.
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Drew
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Glick
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects*; D005108:Extinction, Psychological / Q000187:drug effects*; D005260:Female; D008787:Metoclopramide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D013239:Stereotyped Behavior / Q000187:drug effects*
D001552:Benzazepines; D011954:Receptors, Dopamine; D000661:Amphetamine; D008787:Metoclopramide