Sustained activation does not desensitize the dopamine D2 receptor-mediated control of evoked in vitro release of radiolabeled acetylcholine from rat striatum.

Striatal acetylcholine release is decreased on activation of D2 dopamine receptors. In the present study, it was investigated whether sustained activation of these receptors would reduce their capacity to mediate this effect. It was shown that activation for up to 2 h with high concentrations of either the endogenous ligand, dopamine, or the selective D2 receptor agonist, LY 171555, did not induce desensitization of the D2 receptor-mediated inhibited of electrically evoked [3H]acetylcholine release from rat striatal tissue slices.