Department of Biofunctional Imaging, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Department of Psychiatry and Neurobiology, Kanazawa University, Kanazawa, Japan.
Brain Stimul. 2021 Jan-Feb;14(1):154-160. doi: 10.1016/j.brs.2020.12.010. Epub 2020 Dec 28.
Transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) hypothetically modulates cognitive functions by facilitating or inhibiting neuronal activities chiefly in the cerebral cortex. The effect of tDCS in the deeper brain region, the basal ganglia-cortical circuit, remains unknown.
To investigate the interaction between γ-aminobutyric acid (GABA) concentrations and dopamine release following tDCS.
This study used a randomized, placebo-controlled, double-blind, crossover design. Seventeen healthy male subjects underwent active and sham tDCS (13 min twice at an interval of 20 min) with the anode placed at the left DLPFC and the cathode at the right DLPFC, followed by examinations with [C]-raclopride positron emission topography (PET) and GABA-magnetic resonance spectroscopy (MRS). MRS voxels were set in the left DLPFC and bilateral striata. Paired t-tests and regression analyses were performed for PET and MRS parameters.
MRS data analyses showed elevations in GABA in the left striatum along with moderate reductions in the right striatum and the left DLPFC after active tDCS. PET data analyses showed that reductions in [C]-raclopride binding potentials (increase in dopamine release) in the right striatum were inversely correlated with those in the left striatum after active tDCS. GABA reductions in the left DLPFC positively correlated with elevations in GABA in the left striatum and with increases in right striatal dopamine release and negatively correlated with increases in left striatal dopamine release.
The present results suggest that tDCS to the DLPFC modulates dopamine-GABA functions in the basal ganglia-cortical circuit.
经颅直流电刺激（tDCS）作用于背外侧前额叶皮层（DLPFC），通过促进或抑制主要在大脑皮层中的神经元活动，假设可以调节认知功能。tDCS 在更深的脑区，基底节-皮层回路中的作用尚不清楚。
研究 tDCS 后γ-氨基丁酸（GABA）浓度与多巴胺释放之间的相互作用。
本研究采用随机、安慰剂对照、双盲、交叉设计。17 名健康男性受试者接受了左侧 DLPFC 阳极和右侧 DLPFC 阴极的真刺激和假刺激（间隔 20 分钟，各 13 分钟），随后进行 [C]-raclopride 正电子发射断层扫描（PET）和 GABA 磁共振波谱（MRS）检查。MRS 体素设置在左侧 DLPFC 和双侧纹状体。对 PET 和 MRS 参数进行配对 t 检验和回归分析。
MRS 数据分析显示，真刺激后左侧纹状体中的 GABA 升高，右侧纹状体和左侧 DLPFC 中的 GABA 中度减少。PET 数据分析显示，真刺激后右侧纹状体中 [C]-raclopride 结合势（多巴胺释放增加）的减少与左侧纹状体中的减少呈负相关。左侧 DLPFC 中的 GABA 减少与左侧纹状体中 GABA 的增加以及右侧纹状体中多巴胺释放的增加呈正相关，与左侧纹状体中多巴胺释放的增加呈负相关。
本研究结果表明，DLPFC 的 tDCS 调节了基底节-皮层回路中的多巴胺-GABA 功能。
