Zhang Wenjing, Liu Naici, Zhao Youjin, Yao Chenyang, Yang Dan, Yang Chengmin, Sun Hui, Wei Xia, Sweeney John A, Liang Huilou, Zhang Miaoqi, Gong Qiyong, Lui Su
Department of Radiology and Functional and Molecular Imaging Key Laboratory of Sichuan Province West China Hospital of Sichuan University Chengdu China.
Huaxi MR Research Center (HMRRC) West China Hospital of Sichuan University Chengdu China.
MedComm (2020). 2023 Aug 7;4(4):e335. doi: 10.1002/mco2.335. eCollection 2023 Aug.
Repetitive transcranial magnetic stimulation (rTMS) is increasingly used to treat neuropsychiatric disorders. Inhibitory and excitatory regimens have been both adopted but the exact mechanism of action remains unclear, and investigating their differential effects on laminar diffusion profiles of neocortex may add important evidence. Twenty healthy participants were randomly assigned to receive a low-frequency/inhibitory or high-frequency/excitatory rTMS targeting the left dorsolateral prefrontal cortex (DLPFC). With the brand-new submillimeter diffusion tensor imaging of whole brain and specialized surface-based laminar analysis, fractional anisotropy (FA) and mean diffusion (MD) profiles of cortical layers at different cortical depths were characterized before/after rTMS. Inhibitory and excitatory rTMS both showed impacts on diffusion metrics of somatosensory, limbic, and sensory regions, but different patterns of changes were observed-increased FA with inhibitory rTMS, whereas decreased FA with excitatory rTMS. More importantly, laminar analysis indicated laminar specificity of changes in somatosensory regions during different rTMS patterns-inhibitory rTMS affected the superficial layers contralateral to the DLPFC, while excitatory rTMS led to changes in the intermediate/deep layers bilateral to the DLPFC. These findings provide novel insights into acute neurobiological effects on diffusion profiles of rTMS that may add critical evidence relevant to different protocols of rTMS on neocortex.
重复经颅磁刺激（rTMS）越来越多地用于治疗神经精神疾病。抑制性和兴奋性治疗方案均已采用，但确切的作用机制仍不清楚，研究它们对新皮质层状扩散分布的不同影响可能会提供重要证据。20名健康参与者被随机分配接受针对左侧背外侧前额叶皮质（DLPFC）的低频/抑制性或高频/兴奋性rTMS。利用全新的全脑亚毫米扩散张量成像和基于表面的专门层状分析，在rTMS前后对不同皮质深度的皮质层的分数各向异性（FA）和平均扩散（MD）分布进行了表征。抑制性和兴奋性rTMS均对体感、边缘和感觉区域的扩散指标有影响，但观察到不同的变化模式——抑制性rTMS使FA增加，而兴奋性rTMS使FA降低。更重要的是，层状分析表明在不同rTMS模式下体感区域变化的层状特异性——抑制性rTMS影响DLPFC对侧的浅层，而兴奋性rTMS导致DLPFC双侧的中间/深层发生变化。这些发现为rTMS对扩散分布的急性神经生物学效应提供了新的见解，这可能会为rTMS在新皮质上的不同方案提供关键证据。
