Abnormal Brain Structure And Functional Network In Young Smokers:a Graph Theory Analysis Study

Adolescence is the key period for the development of the cognitive control and emotional management.Smoking addiction can be toxic to health and mental health.With the development and application of imaging technology,people have made great progress in the understanding of smoking addiction.Many previous studies on smoking addiction have found that abnormal brain structures and behaviors associated with smoking addiction.However,little is known about the changes in topological organization of white matter(WM)structural and functional network in young smokers.In the first study,we constructed the WM networks by the deterministic fiber tracking approach.Graph theoretical analysis was used to compare the topological parameters of WM network(global and nodal)and the inter-regional fractional anisotropy(FA)weighted WM connections between groups.The results demonstrated that both young smokers and nonsmokers had small-world topology in WM network.Further analysis revealed that the young smokers exhibited the abnormal topological organization,i.e.,increased network strength,global efficiency,and decreased shortest path length.In addition,the increased nodal efficiency predominately was located in frontal cortex,striatum and anterior cingulate gyrus(ACG)in young smokers.Moreover,the significant increased FA-weighted WM connections were mainly found in the PFC,ACG and supplementary motor area(SMA)regions.Meanwhile,the network parameters were correlated with the nicotine dependence severity(FTND)scores,and the nodal efficiency of orbitofrontal cortex was positive correlation with the cigarette per day(CPD)in young smokers.We revealed the abnormal topological organization of WM network in young smokers,which may improve our understanding of the neural mechanism of young smokers form WM topological organization level.To further explore the abnormal changes of the function network of young smokers,by employing a within-subject design,we compared the two separate occasions(i.e.,smoking abstinence condition and smoking satiety condition)in young smokers.Functional network was constructed by calculating the Pearson correlation coefficients among 246 subregions in human Brainnetome Atlas.By comparison the differences in topological parameters between the two occasions,both of smoking abstinence and satiety condition had small-world topology in functional network.,and there is no difference in the global topological parameters.What's more,the decreased nodal efficiency was mainly located in default mode network?Occipital lobe and the subcortical.The correlation analysis results showed that there were significant negative correlations between the sensory thalamus node efficiency changes and the changes in craving induced by 12-h abstinence.We revealed the abnormal topological organization of brain functional network in young smokers,which may improve our understanding of the neural mechanism of abstinence-induced craving in young smokers form brain functional network's topological organization level.In this paper,we explore the abnormal changes of the brain functional network and the white matter structure network in the young smokers.wo found the relationship between the brain network abnormal and the cognitive control/craving defects in the young smokers.we hope that our study can provide an important theoretical basis for the study of the neural mechanism of smoking addiction.