Ultrastructure of the encapsulated corpuscles in the lower lip mucosa of the mouse.

Under the light microscope, the encapsulated corpuscles of the mouse lower lip mucosa were only classified into 4 types, simple, ramifying, branched-axon, and clew-like corpuscles. The ultrastructural characteristics of the branched-axon and clew-like corpuscles, however, were not reported. Five male mice, aged 4 to 8 weeks, were used. The mouse lower lip mucosa were examined with a electron microscope. Two types of corpuscles were distinguished. The first type had numerous branched axon terminals and bilaterally symmetrical and/or asymmetrical Schwann cell cytoplasmic lamellae in a few perineural capsules. The second type did not have perineural capsules. We concluded that these two types fell into the categories of branched-axon and/or clew-like corpuscles in the light microscopical observations. We concluded also that first type fit the category of coiled simple corpuscles and second type fit the category of Meissner-like corpuscles according to the electron microscopical observations.