Morphological Changes of Ruffini Nerve Endings in the Periodontal Ligament of Aged Mice
نویسنده
چکیده
Ruffini nerve endings in the periodontal ligament (PDL) of aged mouse maxillary incisors were investigated by means of immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels. C3H/HeSlc mice were sacrificed by perfusion fixation. Frozen sagittal cryostat sections of decalcified maxillary incisors were prepared and stained by anti-PGP 9.5 antibody, followed by biotinylated anti-IgG, to reveal neural elements in the PDL. Apart from the typical Ruffini endings distributed throughout the lingual PDL, club-shaped nerve terminations with few, if any, microprojections were found among lingual alveolar bone, but not in the lingual PDL of aged mouse incisors. Ultrastructurally, their nerve terminals contained a marked reduction in the number of mitochondria and other cytoplasmic organelles, compared with those in the younger stage. These results illustrated that Ruffini endings in a distinctive area between alveolar bone may be in the hypofunctional stage, causing their structures to undergo a regressive change with aging.
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The Ruffini ending as the primary mechanoreceptor in the periodontal ligament: its morphology, cytochemical features, regeneration, and development.
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