Pharmacological characterization of D1 and D2 dopamine receptors in rat limbocortical areas. I. Frontal cortex

The mesolimbocortical dopaminergic system innervates several brain regions including the frontal cortex. The aim of our work was both to identify and to pharmacologically characterize the dopamine receptors located in this brain area. We found that different selective agonists for D1 receptors were able to increase adenylate cyclase activity, and these effects were antagonized by haloperidol and SCH 23390. Moreover different agonists for D2 receptors inhibited the cyclic AMP generating system, and these effects were prevented by (-)-sulpiride. According to the paradigm that D1 receptors are linked with adenylate cyclase in a stimulatory way, while D2 receptors are linked with the same enzyme in an inhibitory way, our results indicate the presence of both D1 and D2 receptors in rat frontal cortex.