【摘要】 目的:探讨胞外信号调节激酶(ERKⅠ/Ⅱ)在大鼠脊髓背角C-纤维诱发电位长时程增强(LTP)的诱导和维持中的作用。方法:细胞外记录技术在脊髓腰膨大部记录背角浅层神经元C-纤维诱发电位。结果:(1)MEK的选择性抑制剂PD98059(100μmol/L)或SL327(200μmol/L)对脊髓背角C-纤维诱发电位的基础电位没有影响,但可阻断脊髓背角LTP的诱导。(2)PD98059或SL327呈时间依赖性逆转脊髓背角LTP。在LTP诱导后15m in,脊髓局部给予PD98059(100μmol/L)或SL327(200μmol/L)可完全逆转LTP。在LTP诱导后30 m in,单独给予PD98059或SL327,LTP的抑制率分别为62.5%与75.0%。但同样浓度的PD98059或SL327在LTP诱导后1 h,均不能逆转业已建立的LTP。结论:脊髓背角ERKⅠ/Ⅱ的激活参与C-纤维诱发电位LTP的诱导和早期维持。更多还原

【Abstract】 AIM: The role of external-signal regulated kinaseⅠ/Ⅱ(ERKⅠ/Ⅱ) in the induction and maintenance of spinal long-term potentiation(LTP) is evaluated.METHODS: The C-fiber evoked field potentials were recorded at the superficial layers of spinal dorsal horn at the lumbar enlargement.RESULTS:(1) PD98059(100 μmol/L) or SL327(200(μmol/L)),a selective MEK inhibitor,completely blocked LTP induction when applied at 30 min prior to tetanic stimulation.(2) PD98059 or SL327 reversed spinal LTP in a time-dependent manner.At 15 min after LTP induction,PD98059(100 μmol/L) or SL327(200 μmol/L) reversed LTP completely,and at 30 min after LTP induction,the inhibitory rate of spinal LTP inhibited by PD98059 or SL327 was 62.5% and 75.0%, respectively.At 1 h after LTP induction,however,the same concentration of PD98059 or SL327 did not affect the spinal LTP.CONCLUSION: Activation of ERKⅠ/Ⅱ in spinal dorsal horn may be crucial for the induction and the early-phase maintenance of LTP of C-fiber evoked field potentials.更多还原