Watanabe Kazuyuki, Konno Shin-ichi, Sekiguchi Miho, Sasaki Nobuhisa, Honda Takashi, Kikuchi Shin-ichi
Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, Fukushima City, Fukushima, Japan.
Spine (Phila Pa 1976). 2007 May 20;32(12):1265-71. doi: 10.1097/BRS.0b013e318059aef8.
An experimental study on mechanical allodynia, c-Fos expression, and 200-kDa-neurofilament immunoreactive (IR) afferent expression in the substantia gelatinosa related to compression of dorsal root ganglion (DRG).
To evaluate the presence of allodynia in DRG compression model and to demonstrate that the structural changes of spinal dorsal horn related to DRG compression.
A previous experimental report has demonstrated that the peripheral nerve injury may trigger some structural changes of the superficial spinal dorsal horn. These changes of the spinal dorsal horn were thought to be important for the modulation of pain sensations such as allodynia.
Sixty-eight male rats were used. The left L5 lamina was exposed and a drill hole was made in it. A stainless rod was placed close to the left L5 DRG through the drill hole. Behavioral testing with von Frey filament was performed. On day 28 after surgery, c-Fos expression in the spinal dorsal horn by non-noxious stimulation was examined. L5 spinal cord and bilateral L5 DRG specimens were stained with antibody for 200-kDa neurofilament (RT97). In addition, 2 or 3 spinal cord sections per rats were processed for immunoelectron microscopy.
In the DRG compression group, the mechanical withdrawal threshold was decreased, c-Fos expression by non-noxious stimulation was observed in the spinal dorsal horn, and there were many RT97-IR afferents in the superficial spinal dorsal horn. Immunoelectron microscopic observations showed that RT97-IR terminals made synaptic contact with neurons in the superficial spinal dorsal horn. There were no significant differences in the distribution of RT97-IR neurons in DRG between compression and sham group.
DRG compression induced allodynia and that RT97-IR afferents increased in the superficial dorsal horn of the spinal cord. The increase of RT97-IR afferents may be related to the mechanisms for the observed allodynia.
一项关于与背根神经节（DRG）压迫相关的脊髓胶状质中机械性异常性疼痛、c-Fos表达及200-kDa神经丝免疫反应性（IR）传入纤维表达的实验研究。
评估DRG压迫模型中异常性疼痛的存在，并证明与DRG压迫相关的脊髓背角的结构变化。
先前的一份实验报告表明，周围神经损伤可能引发脊髓背角浅层的一些结构变化。脊髓背角的这些变化被认为对诸如异常性疼痛等痛觉调制很重要。
使用68只雄性大鼠。暴露左侧L5椎板并在其上钻孔。通过该钻孔将一根不锈钢棒靠近左侧L5 DRG放置。用von Frey细丝进行行为测试。在手术后第28天，检查非伤害性刺激下脊髓背角中的c-Fos表达。用200-kDa神经丝（RT97）抗体对L5脊髓和双侧L5 DRG标本进行染色。此外，对每只大鼠的2或3个脊髓切片进行免疫电子显微镜检查。
在DRG压迫组中，机械性撤针阈值降低，在脊髓背角观察到非伤害性刺激下的c-Fos表达，并且在脊髓背角浅层有许多RT97-IR传入纤维。免疫电子显微镜观察显示，RT97-IR终末与脊髓背角浅层的神经元形成突触联系。压迫组和假手术组之间DRG中RT97-IR神经元的分布没有显著差异。
DRG压迫诱导了异常性疼痛，并且脊髓背角浅层中RT97-IR传入纤维增加。RT97-IR传入纤维的增加可能与观察到的异常性疼痛的机制有关。
