Noguchi K, Dubner R, De Leon M, Senba E, Ruda M A
Neurobiology and Anesthesiology Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892.
J Neurosci Res. 1994 Apr 1;37(5):596-603. doi: 10.1002/jnr.490370506.
The distribution of dorsal root ganglion (DRG) cell sizes that show changes in preprotachykinin (PPT) gene expression and substance P (SP) levels following axotomy was examined using RNA blot analysis, in situ hybridization histochemistry, and immunocytochemistry. PPT mRNA was induced in medium-sized (1,000-2,000 microns 2) and large-sized (> 2,000 microns 2) cells in the DRG after axotomy. There was a 165% increase in the number of labeled cells after sciatic transection and a 260% increase after spinal nerve transection which results in axotomy of all the cells in the ganglion. The further increase after spinal nerve transection suggests that the induction occurred in axotomized neurons. PPT mRNA label was also present in a reduced number of small (< 1,000 microns 2) cells after axotomy. SP immunoreactivity was also induced in medium- and large-sized cells and reduced in small-sized cells. Our findings suggest that the expression of the PPT gene and SP is differentially regulated in different subpopulations of DRG neurons after axotomy and is consistent with the hypothesis that tachykinins may be important in both sensory transmission and regeneration.
运用RNA印迹分析、原位杂交组织化学和免疫细胞化学技术，研究了背根神经节（DRG）细胞大小的分布情况，这些细胞在轴突切断后前速激肽原（PPT）基因表达和P物质（SP）水平发生了变化。轴突切断后，DRG中中等大小（1000 - 2000平方微米）和大尺寸（> 2000平方微米）的细胞中诱导产生了PPT mRNA。坐骨神经横断后，标记细胞数量增加了165%，脊神经横断后增加了260%，脊神经横断导致神经节中所有细胞的轴突切断。脊神经横断后标记细胞数量的进一步增加表明诱导发生在轴突切断的神经元中。轴突切断后，少量小尺寸（< 1000平方微米）细胞中也存在PPT mRNA标记。中等大小和大尺寸细胞中也诱导产生了SP免疫反应性，而小尺寸细胞中的SP免疫反应性降低。我们的研究结果表明，轴突切断后，DRG神经元的不同亚群中PPT基因和SP的表达受到不同的调节，这与速激肽在感觉传递和再生中可能起重要作用的假说一致。
