AbstractUsing rat's circumvallate papillae, ATPase, alk. Pase and acid Pase of taste buds were observed after the transection of the glossopharyngeal nerve.The taste buds began to disappear after the nerve was cut and were completely lost after ten days. Following the regeneration of the glossopharyngeal nerve, taste buds reappeared from the bottom of the gutters of circumvallate papillae about 25 days after the operation.ATPase was strongly present on the cell membrane of taste bud cells as far as they existed during degeneration and regeneration. Alk. Pase, which is normally localized on the superficial layers of the epithelium overlying the gutters of circumvallate papilla, gradually diminished as the taste buds degenerated and reappeared as the taste buds regenerated; that is, the activity began to diminish three days after the operation, became feeble after ten days and reappeared after 25 days. It is concluded that taste bud cells secrete alk. Pase in the gutters of circumvallate papillae. Acid Pase activity, usually found in the supranuclear portion of taste bud cells, was intensely reactive during degeneration but did not reappear at the early stage of regeneration of taste bud cells.