Patro Nisha, Nagayach Aarti, Patro I K
School of Studies in Neuroscience, Jiwaji University, Gwalior 474 011, India.
Indian J Exp Biol. 2010 Feb;48(2):110-6.
The presence of microglia in dorsal root ganglia (DRG) has not been reported earlier. The dorsal root ganglia contain satellite glial cells (SGCs) and macrophages, which are considered to have infiltrated from the systemic blood. An attempt was made to investigate whether microglia as found in the central nervous system are also present in the dorsal root ganglia of untreated rats and following experimental peripheral nerve injury. Female adult Wistar rats were subjected to sciatic nerve transection injury on the right hand side. The DRGs of the right side were studied with the contralateral DRGs of the left side serving as controls. The tissues, harvested at different time points after injury, following intracardial perfusion fixation, and frozen sections were immunolabeled with anti-GFAP as a marker for SGCs and anti-Iba1 and OX-6 as markers for microglia and activated macrophagic microglia, respectively. These antibodies were also used in combination to ascertain if Iba1+ cells are the SGCs or otherwise and also if macrophagic OX-6+ cells are Iba1 positive microglia. The results indicate that Iba1 positive microglial cells are different from the SGCs in the DRGs. The Iba1 positive microglial cells respond to the sciatic nerve injury becoming activated and macrophagic and express MHCII molecules. Such activated microglia apparently may serve as neurosupportive cells, providing neuroprotection and scavenging cellular debris in response to the injury.
此前尚未有关于背根神经节（DRG）中存在小胶质细胞的报道。背根神经节包含卫星神经胶质细胞（SGCs）和巨噬细胞，后者被认为是从体循环血液中浸润而来的。本研究旨在探究在未处理大鼠以及实验性周围神经损伤后的背根神经节中，是否也存在如中枢神经系统中所发现的小胶质细胞。成年雌性Wistar大鼠右侧坐骨神经被切断。以左侧对侧背根神经节作为对照，研究右侧背根神经节。在损伤后的不同时间点，经心内灌注固定后采集组织，并将冰冻切片分别用抗GFAP（作为卫星神经胶质细胞的标志物）、抗Iba1和抗OX - 6（分别作为小胶质细胞和活化巨噬性小胶质细胞的标志物）进行免疫标记。这些抗体也被联合使用，以确定Iba1 +细胞是否为卫星神经胶质细胞，以及巨噬性OX - 6 +细胞是否为Iba1阳性小胶质细胞。结果表明，Iba1阳性小胶质细胞与背根神经节中的卫星神经胶质细胞不同。Iba1阳性小胶质细胞对坐骨神经损伤产生反应，被激活并转变为巨噬细胞，同时表达MHCII分子。这种活化的小胶质细胞显然可能作为神经支持细胞，在损伤时提供神经保护并清除细胞碎片。
