PKA参与脊髓背角C-纤维诱发电位LTP的诱导和早期维持

目的: 探讨环一磷酸腺苷依赖的蛋白激酶 (PKA) 在脊髓背角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) 8-Br-cAMP诱发脊髓背角C-纤维诱发电位LTP,且8-Br-cAMP-诱导的 LTP 遮蔽强直刺激诱导的LTP。(2) PKA的选择性抑制剂Rp-CPT-cAMPS阻断C-纤维诱发电位LTP的诱导和时间依赖性翻转C-纤维诱发电位LTP。(3)蛋白质合成抑制剂茴香霉素彻底阻断8-Br-cAMP诱发的 LTP。(4)MAPK选择性抑制剂PD98059阻断8-Br-cAMP诱发的LTP。 结论:脊髓背角神经元存在PKA信号途径,并参与脊髓背角C-纤维诱发LTP的诱导和早期维持。

PKA is required in the induction and early-phase maintenance of LTP of C-fiber evoked field potentials in spinal dorsal horn of adult rats

AIM: The role of cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) in the induction and maintenance of spinal long-term potentiation (LTP) was evaluated. METHODS: The C-fiber evoked field potentials were recorded at the superficial layers of spinal dorsal horn at the lumbar enlargement. RESULTS: (1) 8-Br-cAMP induced LTP of C-fiber evoked field potentials and 8-Br-cAMP-induced LTP occludes tetanus-induced LTP. (2) Rp-CPT-cAMPS, an inhibitor of PKA, blocked the induction of spinal LTP and reversed established LTP of C-fiber evoked field potentials in a time-dependent manner. (3) In the presence of anisomycin, a protein synthesis inhibitor, the potentiation induced by 8-Br-cAMP was completely blocked. (4) PD98059, a selective inhibitor of mitogen-activated protein kinase (MAPK),completely blocked the 8-Br-cAMP-induced LTP.CONCLUSION: Activation of PKA signal pathway in spinal dorsal horn may be crucial for the induction and the early-phase maintenance of LTP of C-fiber evoked field potentials.