Modulation of daily water intake by dopamine in caudate and accumbens nuclei in rats.

Bilateral lesions of accumbens and caudate nuclei resulted in significant and sustained increase in water intake. Administration of different doses of dopamine (DA) into these nuclei facilitated a dose-dependent increase in 24-h water intake, whereas injection of spiperone following administration of DA inhibited DA-facilitated water intake in a dose-dependent manner. Conversely, administration of DA and spiperone did not elicit any change in water intake in septal nuclei; rather septal lesion facilitated the water intake. This suggests that the nucleus accumbens and nucleus caudatus act as facilitatory thirst areas and that DA is a possible dipsogenic neurotransmitter in these nuclei. This also suggests that the nucleus septal lateralis is a thirst-inhibiting centre where DA may not be involved in dipsogenesis.