Distribution of serotonin 5-HT 1C receptor mRNA in adult rat brain

Based on in situ hybridization histochemistry (ISHH), we describe the anatomical distribution of the serotonin 5-HT 1C receptor mRNA. In addition to the very high levels in epithelial cells of the choroid plexus, 5-HT 1C receptor mRNA is found throughout the limbic system, in catecholaminergic cells and in serotonergic neurons. Receptor transcripts are also present in the hypothalamus, numerous motor nuclei and the subthalamus. Our results correlate well with serotonin (5-HT) innervation and receptor binding. Receptor mRNA is present in many brain structures in addition to regions previously shown to have 5-HT 1C receptor binding. The distribution of this receptor mRNA suggests that the 5-HT 1C receptor may mediate a number of the central effects of 5-HT.