Dalong Guo, Jiyuan Li, Yubin Zhou, Yufei Qin, Jinghua Yang, Cong Wang, Hongbo Jia
Air Force Medical Center, Air Force Medical University, Beijing, China.
Beijing Shijitan Hospital, Beijing, China.
Front Neurosci. 2021 Feb 17;15:629331. doi: 10.3389/fnins.2021.629331. eCollection 2021.
The temporoparietal junction plays key roles in vestibular function, motor-sensory ability, and attitude stability. Conventional approaches to studying the temporoparietal junction have drawbacks, and previous studies have focused on self-motion rather than on vestibular spatial perception. Using transcranial direct current stimulation, we explored the temporoparietal junction's effects on vestibular-guided orientation for self-motion and vestibular spatial perception. Twenty participants underwent position, motion, and time tasks, as well as functional magnetic resonance imaging scans. In the position task, cathodal transcranial direct current stimulation yielded a significantly lower response in the -6, -7, -8, -9, -10, -11, and -12 stimulus conditions for leftward rotations ( < 0.05). In the time task, the temporal bias for real transcranial direct current stimulation significantly differed from that for sham stimulation ( < 0.01). Functional magnetic resonance imaging showed that cathodal transcranial direct current stimulation suppressed functional connectivity between the temporoparietal junction, right insular cortex, and right supplementary motor area. Moreover, the change in connectivity between the right temporoparietal junction seed and the right insular cortex was positively correlated with temporal bias under stimulation. The above mentioned results show that cathodal transcranial direct current stimulation induces immediate and extended vestibular effects, which could suppress the functional connectivity of the temporoparietal junction and in turn reduce contralateral spatial and temporal perception. The consistent variation in temporal and spatial bias suggested that the temporoparietal junction may be the cortical temporal integrator for the internal model. Moreover, transcranial direct current stimulation could modulate the integration process and may thus have potential clinical applications in vestibular disorders caused by temporoparietal junction dysfunction.
颞顶联合区在前庭功能、运动感觉能力和姿态稳定性方面发挥着关键作用。研究颞顶联合区的传统方法存在缺陷，且以往研究主要聚焦于自我运动而非前庭空间感知。我们使用经颅直流电刺激，探究了颞顶联合区对自我运动的前庭引导定向和前庭空间感知的影响。20名参与者接受了位置、运动和时间任务，以及功能磁共振成像扫描。在位置任务中，阴极经颅直流电刺激在向左旋转的-6、-7、-8、-9、-10、-11和-12刺激条件下产生的反应显著更低（<0.05）。在时间任务中，真实经颅直流电刺激的时间偏差与假刺激的时间偏差显著不同（<0.01）。功能磁共振成像显示，阴极经颅直流电刺激抑制了颞顶联合区、右侧岛叶皮质和右侧辅助运动区之间的功能连接。此外，右侧颞顶联合区种子点与右侧岛叶皮质之间连接性的变化与刺激下的时间偏差呈正相关。上述结果表明，阴极经颅直流电刺激会诱发即时和持续的前庭效应，这可能会抑制颞顶联合区的功能连接，进而降低对侧的空间和时间感知。时间和空间偏差的一致变化表明，颞顶联合区可能是内部模型的皮质时间整合器。此外，经颅直流电刺激可以调节整合过程，因此可能在由颞顶联合区功能障碍引起的前庭疾病中具有潜在的临床应用价值。
