Baseline Cerebro-Cerebellar Functional Connectivity in Afferent and Efferent Pathways Reveal Dissociable Improvements in Visuomotor Learning

Yi-Cheng Lin; Yun R Lien; Shang-Hua N Lin; Yi-Chia Kung; Chu-Chung Huang; Ching-Po Lin; Li-Hung Chang

doi:10.3389/fnins.2022.904564

Baseline Cerebro-Cerebellar Functional Connectivity in Afferent and Efferent Pathways Reveal Dissociable Improvements in Visuomotor Learning

Front Neurosci. 2022 May 26:16:904564. doi: 10.3389/fnins.2022.904564. eCollection 2022.

Authors

Yi-Cheng Lin^{1

2}, Yun R Lien¹, Shang-Hua N Lin¹, Yi-Chia Kung¹, Chu-Chung Huang^{3

4}, Ching-Po Lin¹, Li-Hung Chang^{1

5}

Affiliations

¹ Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
² Taipei Municipal Gan-Dau Hospital, Taipei, Taiwan.
³ Institute of Brain and Education Innovation, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
⁴ Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China.
⁵ Institute of Philosophy of Mind and Cognition, National Yang Ming Chiao Tung University, Taipei, Taiwan.

Abstract

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.

Keywords: cerebellum; cerebro-cerebellar connections; dentate nucleus; dentato-thalamo-cortical pathways; functional connectivity; rTMS; visuomotor coordination.