Sensory innervation of gingival and alveolar mucosa of the house musk shrew (Suncus murinus).

Abstract

260YAMAMOTO, T. and SAKADA, S. Sensory Innervation of Gingival and Alveolar Mucosa of the House Musk Shrew (Suncus murinus). Tohoku J. exp. Med., 1986, 150 (3), [327][328][329][330][331][332][333][334][335][336] The lingual gingival and the alveolar mucosa of mandible of the house musk shrew (Suncus murinus) were stained by methylene blue vital staining or osmic acid staining, and mounted as whole thickness preparations. The sensory innervation and the distribution of sensory receptors were investigated with a light microscope. The nerve fibers supplying these regions derive from the sublingual nerve, which ascend in the mucosa as they branch out. Sensory receptors found in the present study are of four kinds ; free nerve endings, bushlike nerve endings, Merkel cell-neurite complexes and encapsulated corpuscles. The Merkel cell-neurite complexes were scarce and localized in the upper margin of gingival mucosa. The bush-like nerve endings were distributed preferentially in the alveolar mucosa, in which their maximum density was 9-23 per mmz. Among the organized receptors, the encapsulated corpuscles appeared most frequently throughout the mucosal area investigated, and their maximum density amounted to 27-56 per mmz in the gingival mucosa. These corpuscles were relatively small and poorly differentiated. Although the bush-like nerve endings and the encapsulated corpuscles were fewer in the third molar region, there was no obvious regional difference in their distribution densities from the premolar region to the second molar region. sensory innervation ; sensory receptors ; distribution density ; oral mucosa ; house musk shrew In comparison with the primates, carnivora and rodents, a little information is available on the insectivores concerning the morphology of sensory receptors in the oral mucosa. Early light microscopic studies have shown the characteristics of sensory receptors in the hard palate (Botezat 1907) and the gingiva Stewart and Lewinsky 1939) of the mole, and the hard palate (Ogasawara et al. 1954) and the soft palate (Ohtomo 1955) of the hedgehog. These studies have also mentioned the location of receptors in relation to the epithelial layer. Osanai (1975) has demonstrated the various kinds of sensory receptors in the several parts of oral cavity of the Japanese shrew-mole, and given some brief comments on their distribution patterns. As far as can be ascertained, no quantitative investigation ever has been made of the distribution density of

Study on the Role of Histochemical Stains in Identifying Merkel Cells in Dogs

“…Later, Ranvier () used gold chloride technique and Retzius (), Dogiel (), and Miller et al () introduced the methylene blue techniques to describe similar cells in the epidermis of mammals. Yamamoto and Sakada () also reported Merkel cell‐neurite complexes to be stained by methylene blue vital staining and osmic acid staining. However, none of these techniques stained the MCs itself in the skin samples included in our study but showed the expanded intraepithelial disc‐like nerve endings which end in close association with them.…”