Continual neurogenesis of vomeronasal neurons in vitro

We developed a culture system of vomeronasal neurons in which continuous degeneration and regeneration of axon bundles were observed. Partially dissociated vomeronasal cells from rat embryonic day 15 were grown in culture and formed a miniature vomeronasal-like epithelium. We called these structures vomeronasal pockets. They contained both vomeronasal neurons and supporting cells. They formed a spherical structure with a central cavity where microvilli protruded from supporting cells. Mature vomeronasal neurons with well-developed microvilli were not observed in the vomeronasal pocket. The time period between degeneration of axon bundles and the next was about 2 weeks. When vomeronasal pockets were incubated with 5 microgram/mL aphidicolin, an inhibitor of cell division, regeneration of axon bundles was not observed after degeneration. These results suggest that vomeronasal neurons in culture undergo continuous regeneration but do not fully mature. In this culture system, vomeronasal pockets survived for over 1 year.