Wen Hui-Zhong, Gao Shi-Hao, Zhao Yan-Dong, He Wen-Juan, Tian Xue-Long, Ruan Huai-Zhen
Department of Neurobiology, College of Basic Medical Science, Chongqing Key Laboratory of Neurobiology, Third Military Medical UniversityChongqing, China.
Department of Pathophysiology and High Altitudepathology, College of High Altitude Military Medicine, Third Military Medical UniversityChongqing, China.
Front Behav Neurosci. 2017 Jun 13;11:115. doi: 10.3389/fnbeh.2017.00115. eCollection 2017.
: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. : This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. : Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). : Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. : Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications.
经颅直流电刺激（tDCS）通过调节皮层兴奋性被广泛用于治疗人类神经紊乱和神经性疼痛。tDCS的有效性受其刺激参数影响，但尚无系统研究来指导不同参数的选择。本研究旨在评估初级运动皮层（M1）的tDCS对大鼠慢性神经性疼痛的影响，并测试镇痛的最佳参数组合。利用慢性压迫损伤（CCI）的慢性神经性疼痛模型，我们在不同参数条件下，包括刺激强度、刺激时间、干预时间和电极位置（雄性/雌性CCI模型中结扎爪同侧或对侧M1），测量了阳极tDCS（A-tDCS）前后的疼痛阈值。在M1上施加A-tDCS后，我们观察到镇痛效果取决于不同参数。首先，我们发现重复A-tDCS比单次刺激具有更长的镇痛效果，同侧tDCS（ip-tDCS）和对侧tDCS（con-tDCS）对神经性疼痛均产生持久的镇痛效果。其次，镇痛效果呈强度依赖性和时间依赖性，高强度比低强度效果更好，长刺激持续时间比短刺激持续时间效果更好。第三，损伤后干预的时机影响刺激结果，早期使用tDCS是预防疼痛发展的有效方法，更频繁的干预在CCI大鼠中诱导更多镇痛，最后，在CCI大鼠的两性中观察到con-tDCS和ip-tDCS具有相似的镇痛效果。制定了用于治疗镇痛效果的tDCS优化方案。在临床应用中使用tDCS产生镇痛效果时应考虑这些发现。
