大鼠脊神经后根切断后脊髓和背根神经节CGRP的表达变化

为观察大鼠脊神经后根切断后相应背根神经节(DRG)和脊髓节段CGRP的表达变化,本研究采用25只健康成年SD大鼠随机分为正常对照组、假手术对照组和L4、5后根切断后3d、7d和14d组(n=5),用免疫组织化学方法结合图像分析技术检测各组相应DRG和脊髓节段内CGRP的表达变化。结果如下:后根切断后3d、7d和14d伤侧DRG内CGRP表达较对照组和对侧明显增强;后根切断后3d脊髓后角CGRP免疫阳性纤维减少,7d、14d时进一步减少;后根切断后3d脊髓前角运动神经元内CGRP表达增加,免疫阳性细胞数增多,7d和14d时表达进一步增强。以上结果提示,脊神经后根切断后DRG和脊髓CGRP表达变化呈现一定的时空模式,可能参与了神经损伤后的再生过程。

CHANGES IN THE EXPRESSION OF CALCITONIN GENE-RELATED PEPTIDE IN SPINAL CORD AND DORSAL ROOT GANGLION AFTER DORSAL RHIZOTOMY

To study the changes of the expression of calcitonin gene-related peptide (CGRP) in the spinal cord and dorsal root ganglia (DRGs) after dorsal rhizotomy, 25 adult Sprague-Dawley rats were randomly divided into normal group, sham-operated group and L4、5 dorsal rhizotomy group, and the experimental group was further divided into 3 d, 7 d and 14 d groups according to the survival time, respectively. The expression of CGRP in the spinal cord and DRG were detected by immunohistochemical staining and image analysis methods. The results showed that: CGRP expression in the ipsilateral DRG was upregulated at day 3, 7 and 14 after dorsal rhizotomy; CGRP immunopositive fibers and terminals in the spinal dorsal horn decreased at day 3, and further reduced at day 7 and 14; The number of CGRP-immunopositive motor neurons as well as CGRP immunoreactivity in ventral horn of spinal cord increased after dorsal rhizotomy. We concluded that the changes of CGRP expression presented a temporo-spatial pattern following dorsal rhizotomy, suggesting that CGRP may participate in the process of degeneration and regeneration after nerve injury.