Biomedical Magnetic Resonance Imaging and Spectroscopy Group, Center for Image Sciences, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands.
Connectome Lab, Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.
J Neurosci Res. 2021 May;99(5):1377-1389. doi: 10.1002/jnr.24793. Epub 2021 Jan 28.
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique implicated as a promising adjunct therapy to improve motor function through the neuromodulation of brain networks. Particularly bilateral tDCS, which affects both hemispheres, may yield stronger effects on motor learning than unilateral stimulation. Therefore, the aim of this exploratory study was to develop an experimental model for simultaneous magnetic resonance imaging (MRI) and bilateral tDCS in rats, to measure instant and resultant effects of tDCS on network activity and connectivity. Naïve, male Sprague-Dawley rats were divided into a tDCS (n = 7) and sham stimulation group (n = 6). Functional MRI data were collected during concurrent bilateral tDCS over the sensorimotor cortex, while resting-state functional MRI and perfusion MRI were acquired directly before and after stimulation. Bilateral tDCS induced a hemodynamic activation response, reflected by a bilateral increase in blood oxygenation level-dependent signal in different cortical areas, including the sensorimotor regions. Resting-state functional connectivity within the cortical sensorimotor network decreased after a first stimulation session but increased after a second session, suggesting an interaction between multiple tDCS sessions. Perfusion MRI revealed no significant changes in cerebral blood flow after tDCS. Our exploratory study demonstrates successful application of an MRI-compatible bilateral tDCS setup in an animal model. Our results indicate that bilateral tDCS can locally modulate neuronal activity and connectivity, which may underlie its therapeutic potential.
经颅直流电刺激（tDCS）是一种非侵入性脑刺激技术，被认为是一种有前途的辅助治疗方法，可以通过对大脑网络的神经调节来改善运动功能。特别是双侧 tDCS 影响两个半球，可能比单侧刺激产生更强的运动学习效果。因此，本探索性研究的目的是为大鼠建立一个同时进行磁共振成像（MRI）和双侧 tDCS 的实验模型，以测量 tDCS 对网络活动和连通性的即时和结果影响。将雄性 Sprague-Dawley 大鼠分为 tDCS 组（n=7）和假刺激组（n=6）。在双侧 tDCS 期间同时采集功能磁共振成像数据，而在刺激前后直接采集静息状态功能磁共振成像和灌注磁共振成像。双侧 tDCS 诱导了一个血液动力学激活反应，表现为不同皮质区域（包括感觉运动区域）的血氧水平依赖信号的双侧增加。皮质感觉运动网络的静息状态功能连接在第一次刺激后降低，但在第二次刺激后增加，这表明多次 tDCS 刺激之间存在相互作用。灌注 MRI 显示 tDCS 后脑血流无明显变化。我们的探索性研究成功地在动物模型中应用了一种与 MRI 兼容的双侧 tDCS 装置。我们的结果表明，双侧 tDCS 可以局部调节神经元的活动和连通性，这可能是其治疗潜力的基础。
