Understanding the mechanisms by which intermittent theta burst stimulation (iTBS) protocols exert changes in the default-mode network (DMN) is paramount to develop therapeutically more effective approaches in the future. While a full session (3000 pulses) of 10 Hz repetitive transcranial magnetic stimulation (HF-rTMS) reduces the functional connectivity (FC) of the DMN and the subgenual anterior cingulate cortex, the current understanding of the effects of a single session of iTBS on the DMN in healthy subjects is limited. Here, we use a previously validated target selection approach for an unprecedented investigation into the effects of a single session (1800 pulses) of iTBS over the DMN in healthy controls. Twenty-six healthy subjects participated in a double-blind, crossover, sham-controlled study. After iTBS to the personalized left dorsolateral prefrontal cortex (DLPFC) targets, we investigated the time lapse of effects in the DMN and its relationship to the harm avoidance (HA) personality trait measure (Temperament and Character Inventory/TCI). Approximately 25–30 min after stimulation, we observed reduced FC between the DMN and the rostral and dorsal anterior cingulate cortex (dACC). About 45 min after stimulation the FC of rostral and dACC strongly decreased further, as did the FC of right anterior insula (AI) with the DMN. Also, we report a positive correlation between the FC decrease in the rostral ACC and the HA domain of TCI, indicating that the HA scores can potentially predict iTBS response. Overall, our results show the time lapse by which iTBS at left-DLPFC targets reduces the FC between DMN and the dACC and right AI, regions typically described as nodes of the salience network.

理解间歇性theta脉冲刺激（iTBS）协议在默认模式网络（DMN）中施加变化的机制对于将来开发治疗性更有效的方法至关重要。虽然完整的疗程（3000个脉冲）的10 Hz重复经颅磁刺激（HF-rTMS）减少了DMN和下属前扣带回皮质的功能连接（FC），但目前对单次iTBS的影响了解健康受试者的DMN有限。在这里，我们使用先前验证过的目标选择方法，对健康对照组中iTBS的单次会话（1800脉冲）对DMN的影响进行了空前的研究。26名健康受试者参加了一项双盲，交叉，假对照研究。在将iTBS定位到个性化的左前外侧前额叶皮层（DLPFC）目标之后，我们研究了DMN中影响的时间流逝及其与避免伤害（HA）人格特质测度（Temperament and Character Inventory / TCI）的关系。刺激后约25–30分钟，我们观察到DMN与前额扣带皮层和背扣带皮层（dACC）之间的FC减少。刺激后约45分钟，与DMN一样，右前岛（AI）的FC也进一步降低了鼻尖和dACC的FC。此外，我们报告了在鼻翼ACC中的FC减少与TCI的HA域之间存在正相关，这表明HA评分可以潜在地预测iTBS反应。总体而言，我们的结果表明，左DLPFC目标上的iTBS减少DMN与dACC和右AI之间的FC所花费的时间，