Conditioned stereotypy: behavioral specification of the UCS and pharmacological investigation of the neural change.
Previous work has shown that conditioned stereotypy can be produced by repeated treatments with d-amphetamine or apomorphine. We replicated this phenomenon and found that, as in previous reports, the amplitude of conditioned stereotypy was about one-third that of the unconditioned stereotypy. On the basis of the hypothesis that the UCS in this conditioning situation is a specific stimulation level of dopamine receptors expressed as a peak behavioral effect (UCR), rats were exposed to the experimental boxes for a brief interval during the peak behavioral effect of the drugs. This procedure produced an amplitude of conditioned stereotypy about two-thirds that of unconditioned stereotypy. The issue of the synaptic mechanism mediating conditioned stereotypy was addressed by examining the effect of pimozide on the behavior. A dose of pimozide that completely blocked apomorphine-unconditioned stereotypy also blocked apomorphine-conditioned stereotypy with no sign of motor impairment. d-Amphetamine-conditioned stereotypy was not completely blocked by a dose of pimozide that completely blocked d-amphetamine-unconditioned stereotypy. The implications of these findings for understanding the neural basis of conditioned stereotypy are discussed.
Hiroi
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Department of Psychology, McGill University, Montreal, Quebec, Canada.
White
N M
NM
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology*; D008297:Male; D010868:Pimozide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects; D013239:Stereotyped Behavior / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*
D011954:Receptors, Dopamine; D010868:Pimozide; D001058:Apomorphine; D003913:Dextroamphetamine