The vomeronasal organ (VNO), because of its ability to detect pheromones,
has an important role in many social and sexual behaviours in mammals. It
also mediates defensive behaviours through detection of protein pheromone
homologues. A detailed morphological description of the post-natal development
of the ‘non-sensory’ epithelium (NSE) of the female rabbit is recorded.
Histological techniques were used to study the NSE of the VNO in post-natal
development of female rabbits. The study focused on the following post-natal
ages: newborn, 1 week, 2 weeks and 1 month (five animals each) beside to two
adult animals. The rabbit VNO was surrounded externally by bony capsule and
internally by cartilaginous capsule. NSE was pseudostratified columnar partially
ciliated epithelium without goblet cells. In addition to basal cells, NSE contained
ciliated and three types of non-ciliated columnar cells (dark, pale and
light). At birth, dark cells may have primary cilia. By 1 month, the cytoplasm
became lighter with less free ribosomes. The pale cells had electron-lucent cytoplasm,
which contained a few organelles. Mitotic figures were observed in basal
and columnar cells, particularly during the first 2 weeks of post-natal development.
Light columnar cells were common during the first week. Numerous leucocytes
and a few nerve endings were detected intra-epithelial. Scanning
electron microscope revealed a gradual increase in height of microvilli of nonciliated
cells. Ciliated cells had cilia and microvilli. Cells were arranged singly,
in clumps or in a dense population of cells. The rabbit VNO-NSE had a
unique morphological structure.