Lin Yi-Cheng, Lien Yun R, Lin Shang-Hua N, Kung Yi-Chia, Huang Chu-Chung, Lin Ching-Po, Chang Li-Hung
Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Taipei Municipal Gan-Dau Hospital, Taipei, Taiwan.
Front Neurosci. 2022 May 26;16:904564. doi: 10.3389/fnins.2022.904564. eCollection 2022.
Visuomotor coordination is a complex process involving several brain regions, primarily the cerebellum and motor cortex. Studies have shown inconsistent resting-state functional magnetic resonance imaging (rsfMRI) results in the cerebellar cortex and dentate nucleus of the cerebro-cerebellar connections. Echoing anatomical pathways, these two different cerebellar regions are differentially responsible for afferent and efferent cerebro-cerebellar functional connections. The aim of this study was to measure the baseline resting-state functional connectivity of different cerebellar afferent and efferent pathways and to investigate their relationship to visuomotor learning abilities. We used different cerebellar repetitive transcranial magnetic stimulation (rTMS) frequencies before a pursuit rotor task to influence visuomotor performance. Thirty-eight right-handed participants were included and randomly assigned to three different rTMS frequency groups (1 Hz, 10 Hz and sham) and underwent baseline rsfMRI and pursuit rotor task assessments. We report that greater baseline functional connectivity in the afferent cerebro-cerebellar pathways was associated with greater accuracy improvements. Interestingly, lower baseline functional connectivity in the efferent dentato-thalamo-cortical pathways was associated with greater stability in visuomotor performance, possibly associated with the inhibitory role of the dentate nucleus and caused a reduction in the efferent functional connectivity. The functional dissociation of the cerebellar cortex and dentate nucleus and their connections, suggests that distinct mechanisms in the cerebellum regarding visuomotor learning, which should be investigated in future research.
视觉运动协调是一个涉及多个脑区的复杂过程，主要包括小脑和运动皮层。研究表明，在脑-小脑连接的小脑皮质和齿状核中，静息态功能磁共振成像（rsfMRI）结果不一致。与解剖学通路一致，这两个不同的小脑区域分别负责传入和传出的脑-小脑功能连接。本研究的目的是测量不同小脑传入和传出通路的基线静息态功能连接，并研究它们与视觉运动学习能力的关系。我们在追踪旋转任务之前使用不同频率的小脑重复经颅磁刺激（rTMS）来影响视觉运动表现。纳入了38名右利手参与者，并将他们随机分配到三个不同的rTMS频率组（1Hz、10Hz和假刺激组），并进行了基线rsfMRI和追踪旋转任务评估。我们报告，传入脑-小脑通路中更强的基线功能连接与更大的准确性提高相关。有趣的是，传出齿状核-丘脑-皮质通路中较低的基线功能连接与视觉运动表现的更大稳定性相关，这可能与齿状核的抑制作用有关，并导致传出功能连接减少。小脑皮质和齿状核及其连接的功能分离，表明小脑中关于视觉运动学习存在不同的机制，这应在未来的研究中进行探讨。
