Morphology of vomeronasal organ cultures from fetal rat.

The vomeronasal organs (VNOs) of rats were cultured from embryonic 15-day littermates on collagen-coated membrane in Dulbecco's modified Eagle's medium containing serum. The explants were observed sequentially and fixed at 4, 6, 8, 10 and 14 days in vitro (DIV). Organogenesis of VNOs and cell differentiation took place in vitro. Patterns of organogenesis of the VNO in vitro were different from those in vivo. Both sensory and supporting cells in the sensory epithelium had microvilli on their surface. Epithelial cells in aggregates of non-sensory epithelial cells had cilia and microvilli on their surface. Vomeronasal axons forming two to three large fascicles were seen originating from the VNO at 4, 6, and 8 DIV, and degenerated at 10 or 14 DIV. Glial cells (ensheathing cells) were observed in the fascicles. These morphological characteristics of VNO cells in vitro were similar to those observed in vivo.