Department of Anatomy, Faculty of Medicine and Health Sciences, UAE University, Al-Ain, PO BOX 17666, UAE.
Neurobiol Dis. 2011 Sep;43(3):725-35. doi: 10.1016/j.nbd.2011.06.002. Epub 2011 Jun 14.
Experimental and clinical data suggest that high-frequency deep brain stimulation (DBS) of different subcortical structures can be used to control or modulate epileptic seizures. Recent studies showed that DBS of the substantia nigra reticulata (SNr) in rats has an anticonvulsant effect on forebrain clonic seizures. The aim of this study was to determine whether DBS of SNr could also suppress tonic epileptic seizures evoked in hindbrain structures. DBS with high frequency often mimics the effects of surgical ablation of a particular area of the brain. However, the optimal parameters of DBS stimulation to induce ablation-like effects on seizures are not well defined. Consequently, in the first experiment we examined the effects of different stimulation frequencies (80, 130, 260 and 390 Hz) on neuronal activation induced in SNr, using c-fos immunocytochemistry. The results showed that the stimulation of the SNr with 80 Hz has no inhibitory effect while stimulation with 130, 260 and 390 Hz produced a remarkable suppressive effect compared with the control unstimulated side. The aim of the second experiment was to determine whether bilateral inhibition of SNr with DBS could suppress tonic seizures induced by electric shock. Statistical analysis showed that the mean tonic seizure scores following SNr stimulation with either 130 or 260 Hz were not significantly different from scores following the application of the electrode without current. The data suggest that DBS of the SNr produces neuronal inhibition but fails to suppress tonic seizures. We conclude, therefore, that DBS of SNr with frequencies used in this study might not be effective for treatment of patients who suffer from tonic epileptic seizures.
实验和临床数据表明，高频深部脑刺激（DBS）不同的皮质下结构可用于控制或调节癫痫发作。最近的研究表明，DBS 的黑质网状部（SNr）在大鼠对前脑阵挛性发作有抗惊厥作用。本研究的目的是确定 SNr 的 DBS 是否也能抑制在脑桥结构中诱发的强直性癫痫发作。高频 DBS 通常模拟特定脑区手术消融的效果。然而，DBS 刺激以诱导对发作具有类似消融效果的最佳参数尚未得到很好的定义。因此，在第一个实验中，我们使用 c-fos 免疫细胞化学检测不同刺激频率（80、130、260 和 390 Hz）对 SNr 中诱导的神经元激活的影响。结果表明，80 Hz 的 SNr 刺激没有抑制作用，而 130、260 和 390 Hz 的刺激与对照未刺激侧相比产生了显著的抑制作用。第二个实验的目的是确定双侧 SNr 的 DBS 是否可以抑制电刺激引起的强直性发作。统计分析表明，SNr 刺激后强直性发作的平均评分与电极无电流时的评分没有显著差异。这些数据表明，SNr 的 DBS 产生神经元抑制，但不能抑制强直性发作。因此，我们得出结论，在这项研究中使用的频率的 SNr 的 DBS 可能对患有强直性癫痫发作的患者的治疗无效。
