Aging and the regulation of striatal dopaminergic mechanisms in mice.
Compensatory responses of striatal dopaminergic mechanisms to chronic drug treatment were tested in C57BL/6J and C57BL/6NNia male mice during the adult lifespan (5, 12, and 24 to 26 months). Chronic treatment with haloperidol (dopamine antagonist) (1.2 or 2 mg/kg/day for 21 days) induced supersensitivity in younger mice (5 and 12 months) as monitored by increased striatal spiroperidol binding sites and increased intensity of apomorphine-induced stereotyped behavior; in contrast, old mice were unaffected. However, chronic treatment with bromocriptine (dopamine agonist) (15 mg/kg/day for 7 days) induced desensitization at all ages, as monitored by reduced spiroperidol binding sites and reduced intensity of stereotyped behavior.
D000375:Aging; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism; D013239:Stereotyped Behavior / Q000187:drug effects; D013997:Time Factors
D011954:Receptors, Dopamine; D001971:Bromocriptine; D013134:Spiperone; D006220:Haloperidol; D001058:Apomorphine