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Dopaminergic regulation of cortical acetylcholine release: Effects of dopamine receptor agonists

1993; Elsevier BV; Volume: 54; Issue: 3 Linguagem: Inglês

10.1016/0306-4522(93)90235-8

1873-7544

Jamie C. Day, H.C. Fibiger,

Neuroscience and Neuropharmacology Research

The regulation of the basai forebrain cholinergic system by D1 and D2 dopamine receptors was assessed in the rat using in vivo microdialysis of cortical acetylcholine. The D1 agonist CY 208–243 significantly increased cortical acetylcholine release; in contrast, the D2 agonists quinpirole and (+)-4-propyl-9-hydroxynaphthoxazine were without significant effects. Moreover, when administered in combination with CY 208–243, quinpirole failed to potentiate the D1 agonist-induced increases in cortical acetylcholine release. The non-selective dopamine receptor agonist apomorphine also increased cortical acetylcholine release, and this was completely blocked by the selective D1 receptor antagonist SCH 23390 and slightly, but not signincantly attenuated by the D2 antagonist raclopride. The present results indicate that stimulation of D1 receptors activates cortically-projecting cholinergic neurons; however, a minor contribution of D2 receptors cannot be excluded.