Differential sensitivity to amphetamine following long-term treatment with clozapine or haloperidol.
When rats were pretreated for 8 consecutive days with 2.0 mg/kg haloperidol, injection of 2.5 or 5.0 mg/kg d-amphetamine 2 or 6 days later resulted in a larger increase in oral behaviors and a more prolonged period of focused sterotypy than in saline-pretreated controls. This increased sensitivity to amphetamine is consistent with the effects of a chronic haloperidol-induced increase in dopamine receptor sensitivity. In contrast, long-term treatment with either d-amphetamine or clozapine produced complex changes in the multiphasic behavioral response to amphetamine, which cannot be explained solely by a shift in the sensitivity of dopamine receptors.
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003024:Clozapine / Q000494:pharmacology*; D003984:Dibenzazepines / Q000494:pharmacology*; D004361:Drug Tolerance; D006220:Haloperidol / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects; D013239:Stereotyped Behavior / Q000187:drug effects
D003984:Dibenzazepines; D011954:Receptors, Dopamine; D000661:Amphetamine; D003024:Clozapine; D006220:Haloperidol