Li Charlotte Qiong, Hoffman Samantha, Nguyen Hieu, Vrana Antonia, Carney Aidan, Duan Ying, Ma Zilu, Zhang Nanyin, Yang Yihong, Lu Hanbing
Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States.
Neuroimaging Research Branch, National Institute on Drug Abuse (NIDA) Intramural Research Program, Baltimore, MD, United States.
Imaging Neurosci (Camb). 2025 Jul 25;3. doi: 10.1162/IMAG.a.92. eCollection 2025.
The therapeutic benefits of transcranial magnetic stimulation (TMS) are believed to stem from neuroplasticity induced by repeated sessions. While animal models have contributed to our understanding of TMS-induced plasticity, there is a need for a rodent model that closely replicates the prolonged conditions experienced by humans. This study aimed to develop a rat model that reflects the spatial and temporal dynamics of human TMS protocols and to evaluate the carryover effects of TMS on the brain at a systems level. Experiments were carried out on two groups of rats (N = 33). In the first cohort, rats were implanted with microwire electrodes to record motor-evoked potential (MEP) signals and received daily sessions of high-density theta burst stimulation (hdTBS) for 5 days. Cortical excitability was assessed through input-output (I-O) curves before and after hdTBS (Day 0 and Day 6). To identify brain regions affected by the longitudinal TMS, the second cohort underwent identical TMS protocol and received fMRI scans on Days 0 and 6 to measure basal cerebral blood volume (CBV). Results reveal that daily hdTBS significantly shifted I-O curves upward in the TMS group (N = 9) compared to the sham group (N = 7), reflecting enhanced cortical excitability. Additionally, fMRI data showed elevated basal CBV in both the stimulation sites and in the connected networks (N = 8 for active TMS and N = 9 for sham), suggesting increased basal metabolism. This study opens a novel platform for further exploring the mechanisms underlying TMS-induced plasticity.
经颅磁刺激（TMS）的治疗效果被认为源于重复治疗所诱导的神经可塑性。虽然动物模型有助于我们理解TMS诱导的可塑性，但仍需要一种能紧密复制人类所经历的长期状况的啮齿动物模型。本研究旨在开发一种能反映人类TMS方案的空间和时间动态的大鼠模型，并在系统水平上评估TMS对大脑的遗留效应。对两组大鼠（N = 33）进行了实验。在第一个队列中，给大鼠植入微丝电极以记录运动诱发电位（MEP）信号，并每天接受高密度θ波爆发刺激（hdTBS），持续5天。在hdTBS之前和之后（第0天和第6天）通过输入-输出（I-O）曲线评估皮质兴奋性。为了确定受纵向TMS影响的脑区，第二个队列接受了相同的TMS方案，并在第0天和第6天接受功能磁共振成像扫描，以测量基础脑血容量（CBV）。结果显示，与假手术组（N = 7）相比，TMS组（N = 9）中每日hdTBS使I-O曲线显著向上移动，反映出皮质兴奋性增强。此外，功能磁共振成像数据显示，刺激部位及其连接网络中的基础CBV均升高（主动TMS组N = 8，假手术组N = 9），表明基础代谢增加。本研究为进一步探索TMS诱导可塑性的潜在机制开辟了一个新的平台。
