The histochemistry of the Merkel cell neuroepithelial endings in cat and rabbit skin and oral mucosa.

The tactile hair disks in the oronasal area of the rabbit registered positive for specific and nonspecific cholinesterase. In the cat, the tactile hair disks were positive for alkaline phosphatase in the same region. The hederiform Merkel-Ranvier ending in the epidermis of the palate was positive for cholinesterase in the rabbit and positive for alkaline phosphatase in the cat. In the rabbit, 4-methoxyleucine aminopeptidase activity was also demonstrated in the focal palate epithelium associated with nerves of the Merkel-Ranvier ending. These histochemical reactions of the Merkel neuroepithelial complexes are associated with the nerve ending and may be a specific indicator of the species' innervation pattern.