Effect of Touch-stimulus on the Expression of C-fos and TrkA in Spinal Cord Following Chronic Constriction Injury of the Sciatic Nerve in Rats

• Published in: Current medical science Vol. 25; no. 2; pp. 219 - 222
• Main Author: 万丽 罗爱林 喻红辉 田玉科
• Format: Journal Article
• Language: English
• Published: China Department of Anesthesiology, Tongji Hospital , Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China 2005
• Subjects: Animals; C-los; Female; Hyperalgesia - etiology; Hyperalgesia - metabolism; Proto-Oncogene Proteins c-fos - biosynthesis; Proto-Oncogene Proteins c-fos - genetics; Random Allocation; Rats; Rats, Sprague-Dawley; Receptor, trkA - biosynthesis; Receptor, trkA - genetics; Sciatic Neuropathy - etiology; Sciatic Neuropathy - metabolism; Spinal Cord - metabolism; TrkA; 坐骨神经; 慢性压缩性损伤; 脊髓麻醉; 触觉刺激; chronic constriction injury; innoxious stimulus; hyperalgesia; C-fos,TrkA
• ISSN: 1672-0733; 2096-5230; 1993-1352; 2523-899X
• DOI: 10.1007/BF02873582

To study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-los and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons following the chronic constriction injury (CCI) of the sciatic nerve in rats, 60 female Sprague-Dawley rats were randomly divided into sham-operation group and CCI group, with each group being further divided into 3 subgroups on the 7th, 14th and 28th day after operation (n=10). The mechanical and the thermal withdrawal threshold were assessed following the touch stiumulation after the CCI, immunohistochemical methods were employed to observe the expression of the C-los and TrkA in spinal dorsal horn. Our results showed that the hyperalgesia appeared on the 4th day and reached the maximal level on the 14th day after operation. The expression of the C-fos also increased significantly and reached its maximal level on the 14th day after the touch-stimulus. Meanwhile, the TrkA expression was elevated significantly in both groups, as compared with basic data, and the difference was statistically significant (P<0.05). It is concluded that the level of the C-fos expression changed with the paw withdrawal threshold variation and increased markedly following the innoxious touch-stimulus. The expression of the TrkA receptors also increased gradually following the development of the neuropathic pain. The results suggest that C-fos may play a crucial role in the development of the hyperalgesia in the earlier-time of the neuropathic pain, but TrkA receptors may be involved in the long-lasting adaptive changes of the central pathway in neuropathic pain.