LOCALIZATION OF THE REV-ERBA ORPHAN RECEPTORS IN THE BRAIN

In the present study, we report the localization of the Rev-ErbA alpha and beta nuclear orphan receptors, two closely related members of the nuclear hormone receptor superfamily, in the brain. Both Rev-ErbA var iant mRNAs were highly expressed in the olfactory bulb, the hippocampu s, and in the granular cells of the cerebellum, areas enriched also in other nuclear orphan receptors. Furthermore, the alpha-isoform was fo und in high amounts in the frontal cortex, the superficial gray layer of the superior colliculus, and the stria terminalis. Lower expression was observed in the nucleus accumbens, the caudate-putamen, and in so me thalamic and brainstem nuclei. The beta-variant, in contrast, was o nly moderately expressed in the cortex, mainly in the striate and retr osplenial cortices. In addition, moderate levels of Rev-ErbA beta mRNA were seen in various thalamic, pontine and brainstem nuclei. We concl ude that the two Rev-ErbA isoforms share a partly similar pattern of e xpression in the brain, especially in areas that also contain other nu clear orphan receptors and that otherwise the localization of the two receptor subtypes is differential.