Histological Studies Of The Vomeronasal Organ Of African Giant Rat (Cricetomys gambianus, Waterhouse)

The vomeronasal organ (VNO), a chemoreceptive organ was studied in African giant rat (Cricetomys gambianus, Waterhouse), a macrosmatic animal, by means of gross dissection and light microscopy. The VNO was located in the rostral part of the base of the nasal septum. It was tubular in shape, about 10.6 mm in length and opened in the rostral region of the nasal cavity, with a blind caudal end that terminated in glandular branches. Its lumen in the middle segment was lined by sensory epithelium on the medial wall and non-sensory epithelium on the lateral wall. The sensory epithelium showed sensory, supporting and basal cells, whereas the non-sensory wall contained psendostratified columnar cells with ciliated epithelium. Vomeronasal glands were present in the lateral wall and on the dorso-lateral region between the sensory and non-sensory epithela. Intraepithelial blood vessels were observed on the medial sensory epithelium. Nerve bundles were also apparent in the medial sensory wall. The vomeronasal capsule incompletely housed the organ and showed ossified areas. The histological observations suggest that the VNO isan important organ in sexual behaviours as in other rodents and will throw more light on future studies of the vomeronasal organ. Keywords: African giant rat, Histology, Chemoreception, Vomeronasal organ