Localization of the Rev-ErbA orphan receptors in the brain

In the present study, we report the localization of the Rev-ErbAα of and β nuclear orphan receptors, two closely related members of the nuclear hormone receptor superfamily, in the brain. Both Rev-ErbA variant mRNAs were highly expressed in the olfactory bulb, the hippocampus, and in the granular cells of the cerebellum, areas enriched also in other nuclear orphan receptors. Furthermore, the (α-isoform was found 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 some thalamic and brainstem nuclei. The β-variant, in contrast, was only moderately expressen in the cortex, mainly in the striate and retrosplenial cortices. In addition, moderate levels of Rev-ErbAα mRNA were seen in various thalamic, pontine and brainstem nuelei. We conclude that the two Rev-ErbA isoforms share a partly similar pattern of expression in the brain, especially in areas that also contain other nuclear orphan receptors and that otherwise the localization of the two receptor subtypes is differential.