大鼠嗅觉神经元的凋亡

目的　研究凋亡是否参与嗅上皮正常生理更替和嗅球摘除后嗅觉神经元死亡后再生过程 ,探讨凋亡与神经元再生的关系。方法　应用原位末端标记法观察正常成年大鼠嗅上皮和摘除嗅球后大鼠嗅上皮 16、32、4 8h和 3、7、30d中凋亡的出现和改变情况。结果　正常成年大鼠嗅上皮中有末端脱氧核苷酸转移酶介导的脱氧三磷酸尿苷缺口末端标记TUNEL阳性细胞 (1.93± 0 .31)个 / 2 0 0 μm],摘除嗅球后TUNEL阳性细胞数增加 ,32h达峰值 (90 .9± 18.0 3)个 / 2 0 0 μm],以后迅速下降 ,维持于低水平。 结论　凋亡参与成年嗅觉神经元生理性更替以及实验性嗅觉神经元死亡和再生的过程。可能是通过直接或间接的信号传导调节神经元前体细胞的增殖和分化

Apoptosis in Olfactory Receptor Neurons of Rats

Purpose To study whether apoptosis play a role in controlling the number of olfactory receptor neurons, so as to reveal the speciality and its relationship in neurogenesis. Methods TdT-mediated dUTP-fluorescein nick end labeling (TUNEL) was applied to detect cells undergoing DNA-fragmentation in situ.And the normal olfactory mucosa was examined among healthy adult rats and that of 16, 32, 48 hours and 3, 7, 30 days after bulbectomy. Results In the intact olfactory epithelium,a subpopulation of immature neurons, as well as mature neurons, showed internucleosomal DNA-fragmentation. The number of TUNEL-labeled neurons increased dramatically 32 hours after removal of olfactory bulb. Then it declined quickly and remained at low level, higher than the control yet. Conclusions Apoptosis might play a role in turnover of the olfactory epithelium and regeneration experimentally.