Histochemical and surface ultrastructural characteristics of the nasal cavity of laughing dove.

Ten apparently healthy, adult laughing doves were used to document detailed histological, histochemical and surface ultrastructural features of the nasal cavity and to investigate the structure-function relationship of the nasal cavity in this species. We observed that the nasal cavity of the laughing dove was composed of three main regions: nasal vestibule, respiratory and olfactory. Each region presented a characteristic epithelial lining. The epithelium varied along the nasal vestibule from keratinized stratified squamous rostrally to non-keratinized stratified squamous in the middle and stratified cuboidal in the caudal region of the nasal vestibule. The respiratory region was lined with pseudostratified columnar epithelium and was initially devoid of both goblet cells and cilia, but cilia then appeared and increased gradually in number close to the olfactory region. The caudal part of the respiratory region presented a stratified cuboidal epithelium. Strong alcianophilic, intra-epithelial mucous glands were identified, starting at the caudal region of the nasal vestibule and extended into the respiratory region. The olfactory region was lined with a pseudostratified epithelium that consisted of three different cell types: olfactory, support cells and basal cells. In conclusion, the current investigation presents new information concerning the histological, histochemical and ultrastructural features of the laughing dove's nasal cavity. Furthermore, the findings of this study may prove to be a valuable contribution to the avian histology and pathology literature.