Structural Basis Of Brain White Matter In Global Motor Perception Aging

The trend of population aging in recent years is becoming increasingly obvious,and the cognitive function and brain aging of healthy elderly people have attracted extensive attention.However,the relationship between white matter(WM)and global motor perception(GMP)aging is not well studied.In this study,multimodal techniques were used to compare the differences in WM volume and diffusion indexes between the elderly and the young group,as well as their correlation with GMP.The study was to explore the relationship between GMP and the changes of WM morphology and microstructure.The structural images and DTI images were collected by structural magnetic resonance imaging(MRI)and diffusion tensor imaging.Then,the whole brain WM volume and DTI data was analyzed by VBM and TBSS.The brain data were analyzed with the experimental results of the GMP behavior test,motor congruence threshold,to determine the association between GMP and structural changes in WM.The behavioral results of GMP test show that the threshold of the healthy elderly group was significantly higher than the young in all levels,which proved that the GMP ability of the elderly was indeed lower than the young group.There is indeed an aging phenomenon of GMP.After TIV and gender were treated as covariables,the results of morphological structure study showed that the volume of WM in several brain regions in the elderly group was significantly smaller than the young,including bilateral inferior parietal(but supramarginal and angular guri),bilateral precuneus,left medial superior frontal gyrus,right insula,right auxiliary motor area,right supplementary motor area,right superior parietal gyrus,right postcentral gyrus,right orbitofrontal cotex medial,bilateral middle frontal gyrus,and right middle occipital gyrus.It is suggested that WM volume of the elderly has extensive aging.Further correlation analysis showed that WM volumes in the left orbitofrontal cotex medial,left middle frontal gyrus,left medial superior frontal gyrus and bilateral inferior parietal was negatively correlated with the motion consistency threshold.The smaller volume of WM in these brain regions,the higher threshold of the individual,that is,the lower sensitivity of GMP.The results suggest that one of the neural mechanisms of decreased GMP may be the atrophy of WM volume in these brain regions.The micro structure of the research results show that FA values of the elderly group in the following brain regions was significantly lower than the young: left sagittal stratum(include inferior longitudinal fasciculus and inferior fronto-occipital fasciculus),bilateral superior longitudinal fasciculus,right posterior thalamic radiation(include optic radiation),right posterior corona radiata,splenium of corpus callosum,right superior corona radiata,right posterior limb of internal capsule,right anterior limb of internal capsule and right anterior corona radiata.In addition,most of the above brain regions were negatively correlated with behavioral indicators,that is,the lower FA value of WM in these brain regions,the higher the threshold.The results suggest that the decrease of FA value in these regions may be related to the increase of threshold value in the elderly.Further analysis revealed that the above differences in FA between groups might be mainly due to the changes of AD.AD in several regions of the elderly group,including the corpus callosum,was significantly lower than that of the young,and correlation analysis found that they were positively correlated with the threshold.This study also found that the reverse trend on the microstructure between groups,such as FA value of the elderly group in the cerebellum foot area is significantly higher than the young,but AD value was significantly lower than the young,and the behavior between indicators and FA values of these regions exist positive correlation,negative correlation and AD value,namely the brain white matter FA value is higher,the AD value is lower,the higher the threshold value.The results suggested that the increased FA values in these brain regions may also be related to the increased threshold in the elderly.The results also suggest that the aging of WM microstructures is very complex and the relationship between the aging and behavioral changes is also very complex,and more experimental studies are needed.The results of this study suggest that GMP aging is associated with a wide range of WM volume atrophy and microscopic changes in the elderly.