Apomorphine-induced flavor-drug associations: a dose-response analysis by the taste reactivity test and the conditioned taste avoidance test.
Apomorphine is a positively reinforcing drug at low to moderate doses, but appears to lose its reinforcing properties at higher doses. In Experiment 1, across a range of doses (0.5-15.0 mg/kg, intraperitoneally), apomorphine produced a CTA over 5 conditioning/testing trials which was not dose-dependent by a single bottle test. The rejection taste reactivity responses of chin rubbing and gaping, however, only occurred at the highest dose of apomorphine (15 mg/kg). In Experiment 2, a CTA test which was designed to more effectively discriminate among the different drug dose conditions indicated that the doses of 2.5, 7.5 and 15 mg/kg of apomorphine produce CTAs of equivalent strength. Our results support the contention that CTAs produced by positively reinforcing drugs are not accompanied by a palatability shift.
Parker
L A
LA
Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario.
Brosseau
L
L
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013649:Taste / Q000187:drug effects*
D001058:Apomorphine