Comparative anatomical and neurohistological observations on the tongue of Japanese dormouse (Glirus japonicus).

Abstract

AbstractOn the dorsum of the Japanese dormose tongue three circumvallate papillae are arranged in an inverted V‐shape. Foliate, fungiform and filiform papillae are also observed. The vallate papillae and the outer wall of the trench are covered with highly cornified stratified squamous epithelium. The taste buds in six rows are located only in the lateral wall of the papilla, having a long taste canal. Ganglion cells lie on the nerve bundles extending into the papilla. Serous glands are plentiful deep in the muscles and their ducts open into the bottom and on the outer wall of the trench. The foliate papillae consist of six to seven folds furnished with taste buds. The serous glands are developed also in this region. The lamina propria of the dorsum is richly supplied with abundant nerves ending free. The fungiform papillae are also supplied with abundant nerves and furnished with taste buds penetrating into the connective tissue. The inferior surface is poor in nerve supply and has neither taste buds nor papillae. The muscle spindle, the thin‐sheathed sensory corpuscle and a peculiar wavy‐coursed end‐apparatus within the nerve bundle are found in the apical region. The dormouse tongue contains many ganglion cells along the nerve bundles.