The Resting State FMRI Study Of Heroin Addicts’ Brain Function Connectivity Change Of The Nucleus Accumbens And The Impact Of MMT

ObjectiveTo explore the changes and effect of functional connectivity(FC) of Naccumbens nucleus(Nacc) of reward network in chronic heroin addicts(HA) using resting-state f MRl(rs-f MRI). To explore the effect of methadone maintenace treatment(MMT) in functional connectivity(FC) of Nacc on heroin addicts, identify the potential neuromechanism of MMT performing on heroin craving. MethodsExperiment 1: Collecting the resting state f MRI data of 26 heroin addicts(HA) and 25 healthy control. Bilateral Nucleus accumbens(Nacc) were set as region of interesting(ROIs) respectively,then the mean time series of which and other voxels within whole brain were analyzed, inter-group analysis was performed with two sample t-test.The partial corrlation between intensity of FC in brain regions showed abnormal FC and the duration/doses of heroin consumption was further investigated. Experiment 2: Craving scores and resting-state f MRI were performed on 37 heroin addicts under MMT and 26 matched heroin addicts(HA) without any treatment. Bilateral Nucleus accumbens(Nacc) were set as region of interesting(ROIs) respectively, inter-group analysis was performed with two sample t-test. The partial corrlation between intensity of FC in brain regions showed abnormal FC and the duration/doses of methadone consumption was further investigated. ResultsExperiment 1: Compared with the NC group, the FC between the right Nacc and the bilateral calcarine gyrus, left middle occipital gyrus were significantly increased in the HA group, while there were no regions showed decreased FC.The FC between the left Nacc and left fusiform gyrus and right precuneus were significantly increased, while between the left Nacc and left dorsal medial/lateral prefrontal cortex and bilateral dorsal anterior cingulate were significantly decreased in the HA group. There was no corrlation between the abnormal FC and the duration/doses of heroin consumption in HA group. 2: Compared with the HA group, the FC between the right Nacc and left dorsal medial/ lateral prefrontal cortex, right dorsal anterior cingulate were significantly increased in the MMT group, the decreased FC regions include right medial orbitofrontal cortex. The FC between the left Nacc and left dorsal medial /lateral prefrontal cortex, right dorsal lateral prefrontal cortex, right dorsal anterior cingulate, left insular cortex were significantly increased in the MMT group, there were no regions showed induced FC. The craving scores of MMT was significantly lower than HA. There was no significant corrlation between the abnormal FC and the duration/doses of methadone consumption in MMT group. ConclusionThe abnormal interaction between Nacc, which is the key brain region of reward system, and the regions which involved in cognitive control and visual spatial attention may contributed to the heroin addiction. However, methadone MMTmay influence the function of the nucleus accumbens through cognitive control and motivation /drive circuits, thereby reducing drug craving of heroin addicts.