RDC8, a recently cloned new putative member of the G protein-coupled receptor family, is exclusively present in the medium-sized neurons of the dorsal and ventral striatum in the rat and dog brains. The existence of a striatum-restricted putative G protein-coupled receptor is of major importance for the understanding of basal ganglia physiology and degenerative diseases pathogeny such as Huntington's and Parkinson's disease. This striatal restricted localization mimics the major striatal dopamine D1 receptor localization. RDC7, another putative G protein-coupled receptor presenting a close sequence similarity with RDC8, is mainly distributed in the cerebral cortex, the amygdala, the hippocampus and the claustrum. This localization is also compatible with that expected from a subtype of dopamine D1 receptors.