Post-traumatic anosima, a common cause of olfactory disorders, is postulated to be a result of the shearing of the fine fila olfactoria where they pass through the cribriform plate. The purpose of the present study is to figure out the whole
process of
degenerative and regenerative changes morphologically after section of the olfactory nerves. The olfactory nerves were cut on the right side just above the cribriform plate before entering into nasal cavity in forty adult Sprague-Dawley rats.
Nasal
tissues were collected as en bloc from five rats in the control group and in each of the seven experimental groups after a certain time interval. Histologic examinations included hematoxylin-eosin stain for conventional morphology,
immunohistochemical
stain using anti-OMP (olfactory marker protein) antiserum and anti-keratin antiserum, and immunofluorescent stain using double immunolabelling. The olfactory epithelium showed the most degenerative change in the 7 day-experimental group. In the
42
day-experimental group, the epithelial thickness was increased to 88.5% (septum) and 92.3% (ethmoid turbinate) of the controls, however, the number of olfactory receptor cells (ORC's) was only increased to 60.2% (septum) and 53.7% (ethmoid
turbinate) of
the controls. On immunofluorescent staining, the carnosine-positive ORC's outnumbered the OMP-positive ORC's in the experimental groups showing regenerative process. This present results are hopefully to contribute to understand the regenerative
process
of the olfactory epithelium after nerve section, and may be very useful as a basic data for clinical application in post-traumatic anosmia.
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