Dopamine D2 receptor antagonists induce immediate early genes in the rat striatum.

The acute effects of dopamine D2 antagonists and agonists on the expression of c-jun, zif-268, ETR101 and c-fos in the rat striatum were studied. A single injection IP of haloperidol (2 mg/kg) or sulpiride (100 mg/kg) produced a rapid and transient increase in c-jun, zif-268 and c-fos mRNA. ETR101 was not activated. These inductions were dose dependent and were specifically blocked by pretreatment with a D2 agonist (1 mg/kg quinelorane). Quinelorane alone had no effect. Thus, dopamine D2 receptors inhibit the expression of a particular set of immediate early genes in the striatum.