Decrease in mRNA levels but not in the density of D2 dopamine receptors in rat striatum after transient forebrain ischemia.

D2 dopamine receptor mRNA was analyzed by in situ hybridization histochemistry in rat striatum 7 days after transient forebrain ischemia. A patchy disappearance of the D2 receptor mRNA was observed in the dorsolateral striatum. In the same area, a disappearance of D1 binding sites occurred in the absence of significant changes in D2 receptor density. These results suggest that, although D2 receptors seem to be apparently unaffected after forebrain ischemia, a long-lasting impairment of their neosynthesis may be present in striatal D2 dopaminoceptive neurons.