Nerve Growth-Factor Receptor And Neurochemical Markers In Human Oral-Mucosa - An Immunohistochemical Study

Background: The innervation of the oral mucosa has so far been studied mainly by histochemical and ultrastructural techniques. Only few studies have investigated the presence of neural proteins and neurotransmitters in human gingival mucosa. Objective: The purpose of the present study was to evaluate the presence and distribution of neural structural and transmitter proteins in different areas of normal human oral mucosa. Method: Indirect immunofluorescence was employed on specimens taken from different mucosal regions (gingiva, lips, gums, palate). Both structural (low-affinity nerve growth factor receptor, NGFr; protein gene product 9.5, PGP 9.5) and neuropeptide markers (substance P; calcitonin gene-related peptide; vasoactive intestinal peptide, neuropeptide Y) were used. Results: NGFr and PGP 9.5 intensely labelled both nerve fibres and selected epithelial cells, while neuropeptide immunoreactivity was scarcely expressed and exclusively localized in nerve fibres, Conclusion: Similarity in the distribution pattern and neurochemistry between oral and cutaneous innervation is apparent. Expression of NGFr could be relevant to the trophism of both the oral innervation and epithelium.