Development of substance P immunoreactivity in the mouse vomeronasal organ.
We investigated the development of substance P immunoreactivity in mouse vomeronasal organs in embryos, juveniles, and adults. In all stages, substance P fibers were found in the receptor-free epithelial area, but never in the neuroepithelium. Substance P fibers were found sparsely in the lamina propria of 15-day-old embryos. Although buds of the vomeronasal glands in the cavernous tissue were observed in 17-day-old embryos, and gradually grew in size and numbers, the substance P fibers around them decreased after about the 13th day. Thus, substance P may be a trophic factor for the development of the vomeronasal glands in the cavernous tissue. We first recognized substance P fibers reaching the surface of the receptor-free epithelium in 13-day-old pups. In 21-day-old mice, substance P fibers were as well developed as in adult mice. Considering the development of the substance P fibers in the receptor-free epithelium and the cavernous tissue, they probably cause the vasodilation of the cavernous tissue via local axon reflexes. These structures may then act as a defense system, eliminating noxious stimulus substances sucked into the vomeronasal organ.
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D009300:Nasal Septum / Q000196:embryology / Q000254:growth & development / Q000294:innervation*; D009412:Nerve Fibers / Q000737:chemistry*; D009831:Olfactory Mucosa / Q000196:embryology / Q000254:growth & development / Q000294:innervation*; D011247:Pregnancy; D013373:Substance P / Q000032:analysis* / Q000276:immunology; D013997:Time Factors
D013373:Substance P