Chronic nicotine use blocks haloperidol-induced increase in striatal D2-dopamine receptor density.

Epidemiologic studies have suggested a positive association in man between nicotine use and the incidence of tardive dyskinesia, a disease characterized by dopaminergic supersensitivity after chronic neuroleptic therapy. In rats, repeated administration of neuroleptics results into dopaminergic supersensitivity and increased density of striatal D2-dopamine receptors. We investigated the effects of 6-week continuous nicotine intake on the neuroleptic (haloperidol)-induced increase in murine striatal D2-dopamine receptor density. Contrary to expectations, our data show that nicotine blocked the increase in D2-dopamine receptor density after neuroleptic administration.