Bone Morphogenetic Protein Receptor IA and IB expression in the adult rat trigeminal nuclei

[Abstract] Bone morphogenetic proteins (BMPs) exert its biological functions by interacting with membrane bound receptors, including bone morphogenetic protein receptor (BMPR) IA and BMPRIB. Although the deep involvement of BMP signaling in the development and functions of the trigeminal nuclei has been postulated, little information is available for which kinds of receptors are expressed in the trigeminal nuclei. We, thus, investigated BMPRIA and BMPRIB expression in the adult rat trigeminal nuclei using immunohistochemistry. BMPRIA and BMPRIB were intensely expressed throughout the trigeminal nuclei. In addition, interesting differences were observed between BMPRIA and BMPRIB expression. For example, BMPRIB prefers dendritic expression than BMPRIA, suggesting that BMPRIB is important in the regulation of dendritic morphology and synaptic homeostasis. Furthermore, BMPRIA and BMPRIB were differentially expressed in the trigeminal nuclei, suggesting that these differences may be important to keep precise interneuronal connections. Interestingly, we also detected BMPRIA and BMPRIB expression in axons. These data indicate that BMPRIA and BMPRIB play pivotal roles also in the adult trigeminal system.