Gontero P, Geuna S, Poncino A, Giacobini Robecchi M G
Dipartimento di Anatomia e Fisiologia Umana Università di Torino.
Boll Soc Ital Biol Sper. 1992 Jan;68(1):17-23.
Amputation of the lizard tail is followed by its complete regeneration over a period of six-eight months. The new tail is innervated only by the last three pairs of spinal nerves upstream from the plane of amputation, since no nerve cells are present in the regenerated. The corresponding dorsal root ganglia increase in volume (hypertrophic ganglia) and most of their sensory neurons become hypertrophic. Satellite cells belonging to this hypertrophic ganglia increase in number. This paper describes an autoradiographic study, after administration of tritiated thymidine, of the hypertrophic dorsal root ganglia of the lizard during tail regeneration. We evaluated the number of satellite cells which neo-synthetize DNA ("labeling index = LI%) and are therefore suitable to undergo cell division. The LI% was significatively increased in hypertrophic ganglia when compared to internal control ganglia (not directly involved in the reinnervation process) and normal ganglia (lizards with intact tails). The comparison between internal control ganglia and normal ganglia showed higher LI% values in the formers, although this difference was not statistically significative. These results are in line with those obtained by other authors and suggest that satellite cells of dorsal root ganglia can undergo cellular proliferation also in the adult, especially in particular experimental conditions.
蜥蜴尾巴被截断后，会在六到八个月的时间内完全再生。新尾巴仅由截断平面上游的最后三对脊神经支配，因为再生部分不存在神经细胞。相应的背根神经节体积增大（神经节肥大），其大多数感觉神经元也变得肥大。属于该肥大神经节的卫星细胞数量增加。本文描述了在给予氚标记胸腺嘧啶核苷后，对蜥蜴尾巴再生过程中肥大的背根神经节进行的放射自显影研究。我们评估了新合成DNA的卫星细胞数量（“标记指数=LI%”），因此这些卫星细胞适合进行细胞分裂。与内部对照神经节（未直接参与再支配过程）和正常神经节（尾巴完整的蜥蜴）相比，肥大神经节中的LI%显著增加。内部对照神经节和正常神经节之间的比较显示，前者的LI%值更高，尽管这种差异没有统计学意义。这些结果与其他作者获得的结果一致，表明背根神经节的卫星细胞在成年期也能进行细胞增殖，尤其是在特定的实验条件下。
