Distributional characteristics of the mRNA for retinoid Z receptor β (RZRβ), a putative nuclear melatonin receptor, in the rat brain and spinal cord

Abstract We investigated the distribution of retinoid Z receptor β (RZR β), a putative nuclear melatonin receptor, mRNA in the rat brain and spinal cord using in situ hybridization. The RZRβ riboprobe uniquely hybridized with the neurons in several sensory pathways including the dorsal horn of the spinal cord, whereas the regions involved in the motor control were generally unlabeled. RZRβ mRNA was also highly expressed in the dorsomedial portion of the suprachiasmatic nucleus, pars tuberalis and some limbic areas. This result suggests that RZRβ plays a specific role as a transcription factor in the sensory, neuroendocrine and limbic systems.