Light and scanning electron microscopic histomorphological studies of lingual papillae of albino rat during pre and postnatal life

The present study aimed to describe the morphology and structure of lingual papillae of albino rat fetuses at 19 days of gestation as well as at 1, 3 and 4 weeks postnatal. Twelve tissue specimens were taken from the tongue of three rats from each of the previously mentioned stages and were processed for both light and scanning electron microscopy. In 19 days prenatal fetuses, both mechanical and gustatory papillae were detected on the lingual surface. As regards the filiform papillae they appeared as small rounded projections with rounded tips. Its superficial epithelial coat showed early evidence of keratinization. At the same time, the gustatory fungiform papillae were detected in 19 day fetuses with undifferentiated taste buds and were lined by non-cornified epithelial cells. With the advancement of growth at 1,3 and 4 postnatal weeks three shapes of filiform papillae were distinguished. They were associated with more keratinization of their free ends. During postnatal development at 1,3 and 4 weeks both the circumvallate and the fungiform papillae were detected and attained more differentiated form and their shapes were almost the same as those in the adult rat