A Multimodal Imaging Study On The Neural Mechanism Of Cue-related Responses In Heroin Abstainer

Objective:Cue-related response of heroin addicts is the primary cause of the high rate of relapse.The abnormal activity of the classical reward circuit cannot fully explain the complex addictive behaviors,especially the habitual drug use behavioral and craving under the cue-related circumstances.In this study,the voxel-based morphometry?VBM?,amplitude of low-frequency fluctuation?ALFF?,regional homogeneity?REHO?and functional connectivity?FC?methods were used to explore the neural mechanism of cue-related response in heroin addicts.Methods:35 heroin addicts and 26 healthy controls who met the inclusion criteria were selected.Part 1:First the amount of gray matter volume,white matter volume,cerebrospinal fluid,brain volume,the volume of intracranial and proportion of brain parenchyma were analyzed,then VBM was used to determine the exact brain areas which got lower gray matter volume.Third,the relationship between the total amount of drug use as well the withdrawal time between the volume of gray matter were analyzed.Part 2:Two sample t test was used to analysis regional homogeneity?REHO?and amplitude of low-frequency fluctuation?ALFF?between the two groups.Part 3:Based on the results of ALFF,right inferior frontal gyrus?15,60,-6?was selected as region of interest?ROI?,to explore the differences in functional connectivity between heroin addicts and healthy controls.Results:?1?The amount of whole brain gray matter volume was significantly reduced?p=0.03?,and brain volume was significantly reduced?p=0.05?in heroin group compared to healthy control group.?2?The gray matter of heroin group in the right superior frontal gyrus significantly decreased(p_AlphaSim<0.01).?3?The volume of gray matter in the right middle temporal gyrus and left middle cingulate in heroin addicts decreased significantly with the increase of the total dose(p_AlphaSim<0.01).?4?Compared with healthy controls,the heroin addicts in the right postcentral got significantly higher regional homogeneity,right middle frontal gyrus got significantly lower regional homogeneity(p _AlphaSim<0.01).?5?Right inferior frontal gyrus and left hippocampus got significantly lower amplitude of low-frequency fluctuation in heroin addicts(p_AlphaSim<0.01).?6?Right inferior frontal gyrus and the right caudate got significantly higher functional connectivity,right inferior frontal gyrus and right middle temporal gyrus as well the left precentral got significantly lower functional connectivity?p AlphaSim<0.01?.Conclusion:Even after nearly 4 years of withdrawal on average,the brain structure involved in inhibition of the addiction group still got damaged,and the brain structure of the addiction group was aggravated with the increase of the total amount of addictive drugs.Moreover,the brain regions damaged by addiction do not recover with the increase of the duration of withdrawal,suggesting that the damage of heroin to addicts may be long-term or even permanent.Caudate nucleus and precentral may be the neural basis of cue-related response.Future research can explore the neural mechanism of addiction from the perspective of subregion of addiction.