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Evidence for the existence of intraepithelial nerve endings in the junctional epithelium of rat molars: an immunohistochemical study using protein gene product 9.5 (PGP 9.5) antibody
Author(s) -
Maeda Takeyasu,
Sodeyama Takao,
Hara Kohji,
Takano Yoshiro
Publication year - 1994
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.1994.tb01238.x
Subject(s) - junctional epithelium , epithelium , axoplasm , pathology , anatomy , nerve fiber , free nerve ending , schwann cell , biology , immunoelectron microscopy , lamina propria , immunohistochemistry , neurofilament , chemistry , axon , medicine
Innervation of the junctional epithelium was investigated in rat molars by means of immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels. In comparison with our previous study on same tissues using neurofilament protein (NFP)‐antibody, the PGP 9.5‐immuno‐staining further disclosed numerous nerve fibers in the gingiva of rat molars and revealed the existence of a well‐developed plexus of PGP 9.5‐positive nerve fibers. The interproximal portion also contained numerous nerve fibers. Observation of horizontal sections revealed a denser innervation toward the inner junctional gingival epithelium than the outer marginal epithelium. The nerve fibers, beaded in appearance and extending from the nerve bundles in the lamina propria, penetrated into the junctional epithelial layer and were distributed throughout the junctional epithelium, with some nerves being located near the epithelial surface. Non‐neuronal cells showing PGP 9.5‐immunoreactivity were absent in the junctional epithelium. In immunoelectron microscopy, the axoplasm of nerves in the gingiva was filled with electron‐dense reaction products of PGP 9.5, except for the cell organellae. The nerve fibers were devoid of Schwann cell investment and terminated among the epithelial cells in the junctional epithelium, frequently beneath the epithelial surface. The intraepithelial nerve endings contained various kinds of vesicles including large‐cored ones, supporting the presence of peptidergic innervation shown by previous studies. These findings confirmed the usefulness of PGP 9.5‐immunohisto‐chemistry for the identification of delicated nerve fibers in dental tissue, and suggested the dense network of nerve fibers that may serve as sensory receptor and other functions in the junctional epithelium.