A comparative study of the dopamine-acetylcholine interaction in telencephalic structures of the rat and of a reptile, the lizard Gekko gecko.
The present study describes an investigation in which the dopamine-acetylcholine interaction in the caudate-putamen of the rat was compared with that in other telencephalic regions of the rat and in telencephalic regions of the Gekko gecko. For the rat these regions included the nucleus accumbens and the entorhinal and parietal cortices, for the gekko the striatum, the dorsal ventricular ridge and the cortex. All investigated brain regions in the rat and the gekko receive dopaminergic projections from the ventral mesencephalon. The cholinergic fibers in the rat caudate-putamen and nucleus accumbens are mainly from intrinsic origin, whereas these fibers in the cortex of the rat and in the striatum and the cortex of the gekko predominantly originate from extrinsic sources. The dopamine-acetylcholine interaction was studied at the level of dopamine receptor-mediated inhibition of the depolarization-induced release of radiolabeled acetylcholine in vitro. It appeared that in the caudate-putamen and nucleus accumbens but not in the entorhinal and parietal cortices of the rat stimulation of D2 receptors inhibits the release of acetylcholine. Although we could demonstrate the presence of D2 dopamine receptor binding in all studied telencephalic structures of the gekko, D2 receptor agonists were unable to inhibit the release of radiolabeled acetylcholine in these regions.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism*; D004347:Drug Interactions; D008116:Lizards / Q000378:metabolism*; D051381:Rats / Q000378:metabolism*; D011954:Receptors, Dopamine / Q000378:metabolism; D017448:Receptors, Dopamine D2; D013687:Telencephalon / Q000378:metabolism*
D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D000109:Acetylcholine; D004298:Dopamine