Low neuronal cAMP levels in adults and a further decline following traumatic central nervous system (CNS) injury has been associated with the limited ability of neurons to regenerate. An approach to increase neuronal cAMP levels post injury is electrical stimulation. Stimulation as a tool to promote neuronal growth has largely been studied in the peripheral nervous system or in spared fibers of the CNS and this research suggests that a single session of electrical stimulation is sufficient to initiate a long-lasting axonal growth program. Here, we sought to promote plasticity and growth of the injured corticospinal tract with electrical cortical stimulation immediately after its spinal injury. Moreover, given the importance of rehabilitative motor training in the clinical setting and in translating plasticity into functional recovery, we applied training as a standard treatment to all rats (i.e., with or without electrical stimulation). Our findings show that electrical cortical stimulation did improve recovery in forelimb function compared to the recovery in unstimulated animals. This recovery is likely linked to increased corticospinal tract plasticity as evidenced by a significant increase in sprouting of collaterals above the lesion site, but not to increased regenerative growth through the lesion itself.

中文翻译：

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单节皮质电刺激增强大鼠脊髓损伤后康复性运动训练的功效。

成人中较低的神经元cAMP水平以及创伤性中枢神经系统（CNS）损伤后进一步下降与神经元再生能力有限有关。损伤后增加神经元cAMP水平的一种方法是电刺激。在周围神经系统或中枢神经系统的多余纤维中，已经广泛研究了刺激作为促进神经元生长的工具，这项研究表明，单次电刺激足以启动长期的轴突生长程序。在这里，我们寻求通过电刺激皮层脊髓损伤后立即促进皮层脊髓损伤的可塑性和生长。此外，鉴于康复运动训练在临床中以及将可塑性转化为功能恢复方面的重要性，我们将训练作为对所有大鼠的标准治疗方法（即有或没有电刺激）。我们的发现表明，与未刺激动物相比，皮层电刺激确实改善了前肢功能的恢复。这种恢复很可能与皮质脊髓束可塑性的增加有关，这可以通过病变部位上方的侧支的发芽显着增加来证明，而不是通过病变本身而增加的再生生长。