DARPP-32 as a marker for D-1 dopaminoceptive cells in the rat brain: prenatal development and presence in glial elements (tanycytes) in the basal hypothalamus.

The present article reviews some aspects of the localization of a dopamine- and cyclic AMP-regulated phosphoprotein, DARPP-32, which is assumed to be present in D-1 dopaminoceptive neurons. Its prenatal development starts at day 14 of gestation, is to a large extent complete at birth and seems to be independent of ingrowing dopamine-containing afferents. Rearrangements occur in certain areas, and in some systems DARPP-32 appears to be only transiently expressed. The presence of DARPP-32 in glial structures, the tanycytes, in the arcuate nucleus-median eminence complex in the mediobasal hypothalamus, has given further support to the hypothesis that dopamine, by controlling the shape of the tanycytes and the extension of their processes, can regulate LHRH release by a 'mechanical mechanism'. This hypothesis is now being examined in some experimental paradigms.