The Conjoint Analysis Of Macrostructural And Microstructural Characterizations During Brain Aging

After entering senile phase,the brain will undergo structural changes with the increase of age,such as morphological atrophy,neuronal apoptosis or demyelination.Based on magnetic resonance,brain structure imaging provides imaging evidence for studying the physiological mechanism of normal brain aging.In the process of the brain normal aging,the physiological processes of brain structure in macroscopic and microscopic scales have been widely studied.However,do two physiological processes at different spatial scales exist and what are the internal connections between them in terms of time scale and physiological mechanism of brain aging? At present,there is little systematic research on this problem.Therefore,this paper is expected to preliminarily explore the internal relationship between structural changes in brain aging at two spatial scales through the conjoint analysis of macro-micro structural characteristics,which is of great significance to reveal the neurophysiological mechanism of brain aging and the pathogenesis of aging-related neurodegenerative diseases.A total of 60 healthy participants were recruited.High resolution structural magnetic resonance data and diffusion magnetic resonance data were collected.Using voxel-based morphological analysis and cortical reconstruction,age-related macrostructural changes of gray matter in the whole brain were obtained.The results showed that the macrostructural changes mainly distributed in prefrontal lobe,temporal lobe and thalamus.Meanwhile,diffusion kurtosis imaging parameters were used to reconstruct the microstructure of gray matter and superficial white matter,and the age characteristics were analyzed.The results showed that the microstructural changes of gray matter mainly distributed in prefrontal lobe,occipital lobe,temporal lobe and subcortical nucleus,and the microstructural changes of the superficial white matter mainly distributed in prefrontal lobe,parietal lobe,occipital lobe and temporal lobe.Combined with the results of the two studies,it is found that the macrostructure and the microstructure show age-related dynamic changes,and the regions overlap in spatial distribution.In order to further explore the physiological mechanism of the internal connection between brain macro-microstructure during brain aging,correlation/partial correlation analysis were conducted to quantitatively describe the relationship between them in this study.The results showed that the macroscopic and microscopic structural features were significantly correlated and independent of age in brain regions,such as the prefrontal lobe,occipital lobe and subcortical nuclei of gray matter,and the prefrontal lobe,parietal lobe,occipital lobe and temporal lobes of superficial white matter.In conclusion,the results of this study indicate that during the process of brain aging,the macrostructural and microstructural changes of brain structure have similar spatial distribution patterns.Furthermore,the relationship between macrostructure and microstructure during brain aging and its dependence on age are analyzed innovatively.The internal correlation may reveal the close associations and independent relationships in the physiological process of brain aging from micro to macro,which can further promote the understanding of the neurophysiological mechanism of brain aging.At the same time,this study provides the new method and idea for studying structural changes in brain aging,which has certain reference significance for further for the research of age-related neurodegenerative diseases.