Distribution of novel RFamide-related peptide-like immunoreactivity in themouse central nervous system

Recently, novel mammalian RFamide-related peptides (RFRPs) have been identi fied and suggested to increase prolactin release in the rodent. To assess p ossible functions of RFRPs, we investigated the distribution of RFRPs in th e mouse central nervous system by immunochemical analyses. The quantitative analysis revealed that the concentration of RFRP-like substances was much higher in the brainstem a nd spinal cord than in other regions. Immunohisto chemistry showed that RFRP-like immunoreactive perikarya were localized in the dorsomedial hypothalamic nucleus, the lateral superior olive, and the n ucleus of the solitary tract. The dense networks of immunoreactive fibers w ere found in the lateral parabrachial nucleus, the lateral reticular nucleu s, and the superficial layer of spinal trigeminal nucleus and dorsal horn o f the spinal cord. Thus, RFRPs may participate not only in neuroendocrine f unctions but also in behavioral, sensory, and autonomic functions. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.