title: Immunohistochemistry and ultrastructural characteristics of nerve endings in the oral mucosa of rat.
abstract: The sensory nerve endings of the rat tongue, cheek and palate were studied using immunohistochemical staining and transmission electron microscopy analysis. The specimens were fixed in modified Karnovsky solution and embedded in Spurr resin. Substance P, calcitonin gene-related peptide (CGRP)- and protein gene product 9.5 (PGP b9.5)-containing nerve fibers in the rat tongue, cheek and palate were examined by electronic microscopical analysis and immunohistochemical localization. These fibers run very close to the basal lamina of the epithelium and extend into the filliform and fungiform papillae. Numerous plexiform fibers immunoreactive for substance P, CGRP and PGP 9.5 were found in the connective tissue of mucosa. Electron microscopic observations showed clearly immunostained nerve fibers, which are located very close to the basal lamina of epithelial cells. Some electron-dense granules may be observed in the axoplasms of both substance P and CGRP immunoreactive fibers. Several lamellar corpuscles into the subepithelial connective tissue papillae, Merkel corpuscles and numerous thin unmyelinated and myelinated axons were observed. The terminal axons revealed numerous mitochondria, neurofilaments, microtubules and clear vesicles in the base of axoplasmic protrusions. The lamellar cells showed caveolae and interlamelar spaces filled by amorphous substance. Between the lamellar cells and axoplasmic membrane, and in the adjacent lamellae region, desmosome-type junctions were observed. The quantitative and morphometric analysis showed nerve endings with an average area of 4.83 ± 3.4 μm(2) and 19.4 internal mitochondria in this site and the organized corpuscles with an average area of 79.24 ± 27.24 μm(2) and 24.23 internal mitochondria in this place. All the structures observed are involved in the transmission of pain and mechanoreceptors stimulus of these oral mucosae.
authors.affiliation: Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. watanabe@icb.usp.br
authors.forename: Ii-Sei
authors.initials: IS
authors.lastname: Watanabe
authors.forename: Fernando José
authors.initials: FJ
authors.lastname: Dias
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Mardegan Issa
authors.forename: Carlos Alexandre
authors.initials: CA
authors.lastname: dos Santos Haemmerle
authors.forename: Diego Pulzatto
authors.initials: DP
authors.lastname: Cury
authors.forename: Silvia Honda
authors.initials: SH
authors.lastname: Takada
authors.forename: Marcia Consentino Kronka
authors.initials: MC
authors.lastname: Sosthenes
authors.forename: Marcelo Cavenaghi
authors.initials: MC
authors.lastname: Pereira da Silva
authors.forename: Leila M G
authors.initials: LM
authors.lastname: Campos
authors.forename: Maria Inês
authors.initials: MI
authors.lastname: Nogueira
authors.forename: Mamie Mizusaki
authors.initials: MM
authors.lastname: Iyomasa
mesh_terms: D000818:Animals; D001369:Axons; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D002610:Cheek / Q000294:innervation; D007124:Immunoenzyme Techniques; D018862:Merkel Cells; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000648:ultrastructure; D009061:Mouth Mucosa / Q000294:innervation* / Q000648:ultrastructure; D009411:Nerve Endings / Q000648:ultrastructure*; D010159:Palate / Q000294:innervation; D051381:Rats; D017208:Rats, Wistar; D011984:Sensory Receptor Cells / Q000648:ultrastructure*; D013373:Substance P / Q000032:analysis; D014059:Tongue / Q000294:innervation; D043222:Ubiquitin Thiolesterase / Q000032:analysis
chemical_list: D013373:Substance P; C489034:UCHL1 protein, rat; D043222:Ubiquitin Thiolesterase; D015740:Calcitonin Gene-Related Peptide