Abstract
ATPase and alkaline phosphatase (ALPase) activities were histochemically examined in the sensory corpuscle of mouse digital pads at light and electron microscopic levels. ATPase activity was found on the plasma membranes of the lamellar cells. Moderate activity was present in the caveolae, but little activity could be demonstrated in the other portions of the plasma membrane. Slight ATPase activity was also demonstrated on the plasma membranes of nerve terminals. ALPase activity was found in the caveolae but not on other portions of the plasma membranes of the lamellar cells. ALPase activity was also observed on the nerve terminals. Neither ATPase nor ALPase activity was found on the pre-terminal portions of the nerve fibres. These findings indicate that the caveolae of the lamellar cells may be involved in a transport function and that the plasma membrane of the nerve terminals may have some permeability properties different from those of the pre-terminal portions of nerve fibres.