Author(s): ZHANG, K., KAI, J., DONG, Z., CHUNMEI, C., Institution: SOUTHEAST UNIVERSITY, Country: CHINA, Abstract-ID: 434

Introduction
It is widely accepted that consistent engagement in motor training leads to plasticity in the cerebellum, a region intricately associated with motor skill learning and motor control. Nonetheless, a lack of evidence currently exists regarding the patterns of cerebellar adaptations over a prolonged period of motor training.

Methods
A total of 142 physically active adults were recruited into this study. Based on the years of exercise training, they were divided into three groups, namely group 1 (n = 25, training for less than 1 year, 15M/10F, 20.0 ± 3.8 years old), group 2 (n = 43, training for 1-5 years, 31M/12F, 21.0 ± 2.6 years old) and group 3 (n = 74, training for over 6 years, 47M/27F, 20.9 ± 2.8 years old).
The brain imaging data were acquired using a Philips 3T scanner equipped with a 32-channel standard head coil. The T1 weighted image (T1WI) sequence was used to capture brain structure signals. In addition, echo planar imaging (EPI) sequence was utilized to obtain the resting state blood oxygen level dependent (BOLD)signal. Voxel-based morphometry analysis was conducted on T1WI images to evaluate the morphological plasticity, specifically the gray matter volume (GMV). Simultaneously, BOLD images were processed to obtain such as fractional amplitude of low-frequency fluctuations (fALFF), degree centrality (DC), and regional homogeneity (ReHo) for the assessment of functional plasticity characteristics.
In order to extract the signal values for GMV, fALFF, DC, and ReHo within the specified brain region, a cerebellum template was employed as a mask and applied to the whole brain signal maps. Subsequently, an analysis of covariance (ANCOVA) was conducted among the three groups, with gender and age serving as covariates in these statistical analyses.

Results
(1) As the years of training increase, the GMV shows an increasing trend. ANOVA indicated a main effect (p≤ 0.001) with significant interactions for GMV of both the left (F (2,139) =8.148, η2=0.106) and right (F (2,139) =7.979, η2=0.104) cerebellum.
(2) fALFF, DC, and ReHo exhibit a remarkable consistent trend: as the years of training increase, there is an initial rise followed by a subsequent decline. ANOVA indicated a main effect (p≤ 0.05) with significant interactions for both bilateral cerebellum in fALFF and DC (F left fALFF (2,139) = 3.798, η2=0.053, F right fALFF (2,139) = 3.455, η2=0.048, F left DC (2,139) = 3.998, η2=0.055, F right DC (2,139) = 4.186, η2=0.058).

Conclusion
With the increase in training year, cerebellum structural plasticity shows a continuous upward trend, while functional plasticity exhibits an initial positive change followed by a negative change. The current findings offer new insights into the adaptive responses of the central nervous system during different stages of motor skill learning.