ACUTE DOPAMINE DEPLETION POTENTIATES INDEPENDENT STIMULATORY AND INHIBITORY D-1 DA RECEPTOR-MEDIATED CONTROL OF STRIATAL ACETYLCHOLINE-RELEASE IN-VITRO

Fractional release of [H-3]ACh was evaluated under basal and evoked co nditions in striatal slices from normal and acutely dopamine-depleted adult rats for the influence of D-1- and D-2-DA receptor agonists. The D-1 ligand had no effect on normal slices but DA depletion unmasked t wo independent but simultaneous supersensitive responses: augmentation of K+-evoked and inhibition of glutamate-evoked release. The D-2 liga nd inhibited evoked release in normal slices and this effect was not p otentiated. This is a new cholinergic model of acute D-1 receptor supe rsensitivity.