The dynamic of precursor of the olfactory epithelium of mongrel dogs: an immunohistochemical and ultrastructural study

Olfactory epithelium presents a mechanism of differentiation where stem cells give arise to amplifying progenitor cell which express Mammalian Achaete Scute Homolog 1 (Mash 1). These cells can be differentiated into olfactory receptors. An immunolocalization study and ultrastructural analysis by transmission electron microscopy of olfactory epithelium of mongrel dogs were made using 3 males (one year old) and 2 females (three years old). Labeled cells with positive staining by Proliferating cell nuclear antigen (PCNA) were observed in specific areas of the olfactory epithelium, especially above the basal membrane. The ultrastructure revealed cells adjacent to the basal membrane with morphology resembling sustentacular cells, supporting the idea of renewal of sustentacular and olfactory sensorial cells. Olfactory epithelium contains basal cells committed to self-renewal, characterized by high metabolic activity, identified by positive reaction to PCNA. These results suggested the renewal of sustentacular and sensorial olfactory cells through the same pathway.