Scanning electron-microscopic view of the oral and basal epithelial surfaces of the rat soft palate

We studied corresponding structures on the oral and basal surfaces of the o ral epithelial layer, focusing on the microanatomy of gustatory papillae. S pecimens for scanning electron microscopy were obtained from the rat soft p alates and fixed with a mixture of 2% paraformaldehyde and 1% glutaraldehyd e. They were first prepared without postfixation and conductive-staining to study the oral surface. After examination, the epithelium was reinforced b y additional sputter coating and treated with 6 N NaOH at 60 degreesC to ex foliate the basal epithelial surfaces without any significant artifacts. Th e papillae, showing circular, elliptical or fusiform protuberances on the o ral surface, were classified into two types: types I and II. The type I and type II papillae contained one and two taste pores, respectively. On the b asal epithelial surface, the basal portions of the taste buds were associat ed with concentrically arranged nerve fibers and Schwann cells. Another cha racteristic finding on the basal epithelial surface was the presence of exc retory ducts of minor salivary glands in a close spatial relationship to ta ste buds. It is suggested that saliva coming out through the duct is mixed with food, thus enabling intimate contact with the taste pores of the papil lae. Copyright (C) 2001 S. Karger AG, Basel.