Opposed stages of continuous amphetamine administration: parallel alterations in motor stereotypies and in vivo spiroperidol accumulation.
Rats pretreated with different regimens of chronic d-amphetamine (d-Amp) administration were injected 24 h after cessation of chronic d-Amp with either d-Amp (to test the degree to which it now elicited motor stereotypies) or with [3H]spiroperidol (to study in vivo accumulation in 7 brain regions). Rats pretreated with 28 daily injections of d-Amp subsequently evidenced heightened stereotypies to d-Amp whereas other rats pretreated with the same amount of d-Amp for 28 days using slow-release pellets showed decreased stereotypies to d-Amp. In neither of these chronic groups was spiroperidol accumulation altered. But the administration of d-Amp continuously over briefer periods induced large and phasic alterations in both d-Amp induced stereotypes and in spiroperidol accumulation. Rats given continuous d-Amp for 24 h, allowed a 24 h drug-free period, and then injected evidenced a large potentiation of both stereotypies and in vivo accumulation of spiroperidol in the caudate nucleus, whereas after 5 days of continuous d-Amp administration rats showed attenuated stereotypies and decreased [3H]spiroperidol accumulation in the caudate, accumbens, and substantia nigra. These results imply that brief periods of continuous d-Amp administration produce large and phasic changes in dopamine systems.
D000818:Animals; D001921:Brain / Q000378:metabolism; D002090:Butyrophenones / Q000378:metabolism*; D003913:Dextroamphetamine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects; D013134:Spiperone / Q000378:metabolism*; D013239:Stereotyped Behavior / Q000187:drug effects*
D002090:Butyrophenones; D011954:Receptors, Dopamine; D013134:Spiperone; D003913:Dextroamphetamine