In a continuous series of experiments dealing with the dynamics of the olfactory neuroepithelium, this study was undertaken to explore the survival and turnover rate of olfactory neurons before and after removal of their target. The total number of receptor cells in the mouse olfactory epithelium was estimated and its correlation with age was determined. There is a 64% increase in total number of neurons from one to four months of age followed by a 28% decrease in a period from four to thirteen months of age. / Autoradiographic studies were conducted to describe neuronal renewal and turnover in young adult animals. The results indicate that the percentage of labeled basal cells reached its maximum of 95.5% at 24 hours after the injection of tritiated thymidine. Ten days after injection, labeled basal cells percentage dropped to 47.6% simultaneously with an increase in the percentage of labeled neurons reading 48% of the total labeled cells. By 30 days post injection the percentage of labeled basal cells declined to 8.7%. 74% of the total labeled mature neurons have already disappeared by 55 days postinjection. / Neonatal and young adult mice which underwent unilateral partial bulbectomy were injected with tritiated thymidine 60 days after surgery and then were sacrificed at different time intervals. On the operated side the morphological observations have shown that the olfactory neuroepithelium is thinner than the normal due to a reduction of 11% and 48% in the neuronal population of neonatal and adult bulbectomized mice respectively. Autoradiographic observations indicate that neonatal animals sacrificed 24 hours postinjection had 46.3% more labeled basal cells in the experimental side than in the controls. The labeled basal cells disappeared from the experimental side at a faster rate than those in the control side. / Labeled sensory cell percentage rose from zero percent at 24 hours to 45.8% of the total labeled elements in the operated side at 7 days postinjection while those of the control side comprised only 30.7%. By 15 days after injection, the percentage of labeled neurons in the operated side declined to 36.4% while those of the control still increasing reaching a maximum of 45.8% of the total labeled elements indicating a shorter lifespan of regenerating neurons. / Source: Dissertation Abstracts International, Volume: 44-02, Section: B, page: 0385. / Thesis (Ph.D.)--The Florida State University, 1983.
Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75063 |
Contributors | FITIES, ISMAIL AYAD., Florida State University |
Source Sets | Florida State University |
Detected Language | English |
Type | Text |
Format | 109 p. |
Rights | On campus use only. |
Relation | Dissertation Abstracts International |
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