Lectin histochemistry of taste buds in the circumvallate papilla of the rat

In mammals, taste buds are localized mostly within two regions, i.e. lingual and palatal epithelium. In the lingual epithelium, taste buds are localized in three lingual papillae; fungiform, foliate and circum-vallate papillae. In the palatal epithelium, taste buds are present in the nasoincisor papillae and soft palate. In addition, few taste buds are recognized at the laryngeal surface of epiglottis. Taste buds contain 50–80 elongated specialized epithelial cells (taste cells) and proliferative basal cells (progenitor cells). Ultrastructually, taste cells have traditionally been classified into two types of cells; dark and light cells. Dark cells or type I cells have an electron-dense cytoplasm and thought to be supporting cells. Light cells are characterized by the presence of electron-lucent cytoplasm and further subdivided into two types based on the presence of synaptic vesicles. Light cells without apparent synaptic vesicles are called type II cells, while those with synaptic vesicles are termed as type III cells. Progenitor cells ar