Morphological Adaptations of Lingual Mucosa of Three Age-Stages of the Rock Pigeon Columba Livia Domestica: Using Histological and Immunohistochemical Techniques

The present study was designed to investigate the histological and immunohistochemical characterizations of Rock Pigeon tongue throughout three different age-stages young, adult, and aging. Histologically, the mucosa of examined pigeons consisted of a multilayered (parakeratinized, orthokeratinized and nonkeratinized epithelium) that cover the CT lamina propria and entoglossum cartilage. Surface multilayered mucosa can obviously differentiate into basal, intermediate, and superficial layers. No lingual papillae were observed over the dorsal lingual surface except over the area of the root in both adult and aging pigeons. Lingual glands were distributed along the three lingual parts in three age-stages. Their secretory cells showed a positive affinity toward Alcian blue and revealed a various degree of reactions with PAS except the root in both young and adult pigeons (negative). Both Collagenous and reticular fibers were noted in CT lamina propria layer and around the acini of lingual glands. These fibers were richly localized in aging pigeon tongue. Our findings revealed that PCNA expression in young pigeon was higher if compared to the other two ages. Cytokeratin expressions were markedly noticed in the dorsum epithelium of adult and gradually increase in aging one.Conclusion, these findings correlated with food intake mechanisms and with eating habits.