Characteristic Patterns Of Functional Networks In Methamphetamine Dependent Individuals And Dynamic Alteration At 6 Months Follow-up

Objective1.To understand the functional network mechanism of attentional bias for MA-related cues in MA dependent individuals;2.To verify the characteristic patterns and dynaminc alteration of functional networks connectivity associated with drug-related cue reactivity in MA dependent individuals;3.To investigate the characteristic patterns of cerebellar-cerebral functional connectivity（FC）associated with drug-related cue reactivity in MA dependent individuals.Methods1.Task functional magnetic resonance imaging（f MRI）scans were obtained from30 MA dependent individuals and 33 healthy controls.Differences of functional network activity during MA addiction stroop task were compared between MA and HC groups.Correlations between craving,score of attentional bias and significant brain areas under drug-related cues were also explored within the MA group.2.Resting-state f MRI scans were obtained from 111 MA dependent individuals and 94 healthy controls.62 MA participants were scaned again after about 6（6.55±0.51）months.Seed-based functional connectivity analysis was employed to investigate the patterns and alterations of functional connectivity within and between DMN,SN,ECN in the MA group.We also explored the network mechnisms underlying craving and changes of craving after 6 months abstinence within MA group.Whether resting-state FC of DMN-SN-ECN could predict changes of craving was also identified.3.Resting-state f MRI scans were obtained from 34 MA dependent individuals and31 healthy controls.Seed-based functional connectivity analysis was employed to investigate the differences in cerebellar-cerebral functional connectivity between MA and HC group.Correlations between drug use history and significant functional connectivity were explored within MA group.Then we also explored the cerebellar-cerebral functional network mechnisms of craving in the MA group.Results1.Compared to HCs,activations of brain areas in the DMN and ECN during MA addiction stroop task were significantly increased in the MA group,as well as the scores of attentional bias.Within the MA group,scores of attentional bias were predicted by activations of SFG and angular gyrus under drug-related cues（adjusted R²=0.15,F=3.63,p=0.040）.2.Compared to HCs,the MA group exhibited significantly increased functional connectivity within ECN,and signicantly increased functional connectivity between SN and ECN,ECN and DMN at baseline.Within the MA group,functional connectivity strength of PCC/Precunues-IFG coupling could predict the scores of craving（adjusted R²=0.21,F=15.44,p<0.001）.As the abstinence period prolonged,the MA patients demonstrated increased functional connectivity within SN and ECN,and significantly increased functional connectivity between DMN and SN,SN and ECN,ECN and DMN.In addition,functional connectivity strength of PPC-ITG coupling could predict the changes of craving in the MA group（adjusted R²=0.24,F=20.45,p<0.001）.3.Compared to HCs,the MA group exhibited significantly altered FC between cerebellum and SMN,DMN.Within the MA group,functional connectivity strength of the right cerebellar Lobule VI_ECN-precuneus coupling was negatively correlated with addiction severity（partial correlation coefficient=-0.60,uncorrected p<0.001,p=0.006 Bofferroni corrected）.Conclusion1.Aberrant activations of ECN and SN might underly the neurobiological mechanism of attentional bias for drug-related cues in the MA dependent individuals.2.Altered patterns of functional connectivity were found in the ECN-SN-DMN triple networks in MA patients,which might associate with drug-related craving.As abstinence period prolonged,functional connectivity of the networks showed dynamic alterations,which may relate to the changes of drug craving.3.Aberrant resting-state cerebellar-cerebral FC was found in the MA dependent individuals,which might associate with the regulation of drug-related cue reactivity.