Morphology and immunohistochemistry of the human vomeronasal organ

The vomeronasal system in vertebrates is a widely "used" chemosensory alternative to the olfactory and gustatory systems. It has been found in many amphibian, reptile and mammalian species and contributes to the control of reproductive function and social behavior. Our interests focuses on the putative presence in humans, who regularly loose appropriate central nervous structures during fetal development. In contrast, they do not loose social behavior mechanisms, at least sometimes.

F.Ruysch, 1703: First depiction of the vomeronasal duct (E) in the nasal septum, lateral view. The tube (D) enters the opening of the persistent VND, which occurs in most adult humans. (Ref. SLUB Dresden Anat.A.216)		Endoscopical view into the nasal cavity. The opening of the vomeronasal duct appears as a small pit within the mucosa of the nasal septum. From: Knecht et al., Behav Neurosci 117:1135-1141

In adult humans, the vomeronasal duct is lined out with a specific epithelium, the relevance of which for chemosensory functions is unclear. Most cells are positive for cytokeratin which indicates the epithelial, but not neuronal (chemosensory) nature of the epithelium.		During development, the VNO appears still complete (8th week). We are interested in degeneration and histofunctional properties.		In early development (week 8) the VND is lined up with neuroepithelial cells (PGP9.5). Arrows point at the vomeronasal nerve.