Ultrastructure and Development of the Olfactory Organ in Indigenous Pelophylax Ridibundus (Amphibia, Rana)

Abstract

Two olfactory placodes were formed in early embryonic stages. The olfactory epithelia contain receptor, supporting and basal cells. Receptor cells are represented by elongated ciliated cells or microvillated cells, most of the supporting cells are ciliated and some of them are secretory cells. The olfactory placode developed into a principal cavity that differentiated into three chambers as ciliated supporting cells, secretory supporting cells and abundance of ciliated receptor cells and microvillated cells. We observed a tiny projections of small secretory supporting cells of the principle cavity, arranged in row, known as Bowman’s glands to detect odorants in the air, together with the surrounding supporting cells are presumply responsible for mucus-coating the epithelium of the principle cavity.