Zhao S, Pang Y, Beuerman R W, Thompson H W, Kline D G
Department of Neurosurgery, Louisiana State University Eye Center, Louisiana State University Medical School, New Orleans 70112, USA.
Neurosurgery. 1998 Jun;42(6):1357-62; discussion 1362-3. doi: 10.1097/00006123-199806000-00099.
Clinical reports indicate poor outcomes for avulsion injuries, compared with more peripheral nerve damage. These two different injuries may both affect gene expression in spinal neurons, and the changes in gene expression may be related to the types of injuries.
The brachial plexus of 48 adult male rats was lesioned by either root avulsion close to the spinal cord or distal nerve transection. The rats were quickly revived and remained awake until death at 30, 60, or 120 min after surgery. In rats with avulsive injuries, traumatic sites on the dorsal and ventral horns of the spinal cord were microscopically detected. Immunocytochemical analysis of the c-fos product was performed for the two experimental groups and for sham-treated control animals at the same survival times.
An increase in Fos-like immunoreactivity (FLI) in cells of the spinal cord, at levels C4-T1, was detected at 30 min after nerve transection or root avulsion. The number of FLI-positive cells continued to increase at 60 and 120 min after the nerve injury (P=0.001). FLI-positive cells were compared at the C7 level, in laminae 1 and 2, 3 and 4, and 5 to 10, after the two injuries and were found to be more abundant after the avulsive injury (P=0.0001); furthermore, the number of FLI-positive cells increased with time (P=0.001). In a comparison of all levels, both experimental groups demonstrated significantly greater numbers of FLI-positive cells than did controls, and the group with nerve root avulsion showed significantly (P=0.0001) more FLI-positive cells than did the group with distal nerve transection.
These results suggest that nerve root avulsion from the spinal cord leads to increased and prolonged expression of c-fos and, potentially, greatly increased transcription of new messages for recovery, survival, or cell death.
临床报告显示，与更外周的神经损伤相比，撕脱伤的预后较差。这两种不同的损伤可能都会影响脊髓神经元中的基因表达，并且基因表达的变化可能与损伤类型有关。
48只成年雄性大鼠的臂丛神经通过靠近脊髓的根部撕脱或远端神经横断进行损伤。大鼠迅速苏醒并保持清醒，直至术后30、60或120分钟死亡。在有撕脱伤的大鼠中，显微镜下检测脊髓背角和腹角的创伤部位。对两个实验组以及在相同存活时间的假手术对照动物进行c-fos产物的免疫细胞化学分析。
在神经横断或根部撕脱后30分钟，在C4-T1水平的脊髓细胞中检测到Fos样免疫反应性（FLI）增加。神经损伤后60和120分钟，FLI阳性细胞数量持续增加（P = 0.001）。在两种损伤后，比较C7水平第1和2层、3和4层以及5至10层的FLI阳性细胞，发现撕脱伤后FLI阳性细胞更丰富（P = 0.0001）；此外，FLI阳性细胞数量随时间增加（P = 0.001）。在所有水平的比较中，两个实验组的FLI阳性细胞数量均显著多于对照组，并且神经根撕脱组的FLI阳性细胞数量显著多于远端神经横断组（P = 0.0001）。
这些结果表明，脊髓神经根撕脱导致c-fos表达增加和延长，并且可能极大地增加了用于恢复、存活或细胞死亡的新信息的转录。
