Kwak Youngjong, Lim Seokbeen, Cho Hyun-U, Sim Jeongeun, Lee Sangjun, Jeong Suhyeon, Jeon Se Jin, Im Chang-Hwan, Jang Dong Pyo
Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
Department of Biomedical Engineering, University of Minnesota, MN, USA.
Brain Stimul. 2023 Sep-Oct;16(5):1377-1383. doi: 10.1016/j.brs.2023.09.012. Epub 2023 Sep 15.
Temporal interference stimulation (TIS) is a neuromodulation technique that could stimulate deep brain regions by inducing interfering electrical signals based on high-frequency electrical stimulations of multiple electrode pairs from outside the brain. Despite numerous TIS studies, however, there has been limited investigation into the neurochemical effects of TIS.
We performed two experiments to investigate the effect of TIS on the medial forebrain bundle (MFB)-evoked phasic dopamine (DA) response.
In the first experiment, we applied TIS next to a carbon fiber microelectrode (CFM) to examine the modulation of the MFB-evoked phasic DA response in the striatum (STr). Beat frequencies and intensities of TIS were 0, 2, 6, 10, 20, 60, 130 Hz and 0, 100, 200, 300, 400, 500 μA. In the second experiment, we examined the effect of TIS with a 2 Hz beat frequency (based on the first experiment) on MFB-evoked phasic DA release when applied above the cortex (with a simulation-based stimulation site targeting the striatum). We employed 0 Hz and 2 Hz beat frequencies and a control condition without stimulation.
In the first experiment, TIS with a beat frequency of 2 Hz and an intensity of 400 μA or greater decreased MFB-evoked phasic DA release by roughly 40%, which continued until the experiment's end. In contrast, TIS at beat frequencies other than 2 Hz and intensities less than 400 μA did not affect MFB-evoked phasic DA release. In the second experiment, TIS with a 2 Hz beat frequency decreased only the MFB-evoked phasic DA response, but the reduction in DA release was not sustained.
STr-applied and cortex-applied TIS with delta frequency dampens evoked phasic DA release in the STr. These findings demonstrate that TIS could influence the neurochemical modulation of the brain.
时间干扰刺激（TIS）是一种神经调节技术，可通过基于来自脑外多个电极对的高频电刺激诱导干扰电信号来刺激脑深部区域。然而，尽管有大量关于TIS的研究，但对TIS的神经化学效应的研究却很有限。
我们进行了两项实验，以研究TIS对内侧前脑束（MFB）诱发的阶段性多巴胺（DA）反应的影响。
在第一个实验中，我们将TIS应用于碳纤维微电极（CFM）旁边，以检查其对纹状体（STr）中MFB诱发的阶段性DA反应的调节作用。TIS的拍频和强度分别为0、2、6、10、20、60、130Hz和0、100、200、300、400、500μA。在第二个实验中，我们研究了基于第一个实验，当在皮质上方施加2Hz拍频的TIS（基于模拟的刺激部位靶向纹状体）时，对MFB诱发的阶段性DA释放的影响。我们采用了0Hz和2Hz拍频以及无刺激的对照条件。
在第一个实验中，拍频为2Hz且强度为400μA或更高的TIS使MFB诱发的阶段性DA释放减少了约40%，这种减少一直持续到实验结束。相比之下，拍频不是2Hz且强度小于400μA的TIS对MFB诱发得阶段性DA释放没有影响。在第二个实验中，2Hz拍频的TIS仅降低了MFB诱发的阶段性DA反应，但DA释放的减少并未持续。
在纹状体和皮质施加具有δ频率的TIS会抑制纹状体中诱发的阶段性DA释放。这些发现表明TIS可能会影响大脑的神经化学调节。
