| At the present, human brain is one of the most complex and largest systems in nature. The graph theory provides new ideas and methods for the research of brain science. It is great significance to understand the working mode of the brain and explore the pathological mechanism of cerebral functional diseases from the perspective of the human brain network. Heroin add icition is a kind of chronic recurrence encephalopathy, which is an important medical and social problem need to be solved urgently in our country and even in the world. Protracted abstinence(PA)is one of the common treatment methods in China. It is desirable to improve the quality of treatment and rehabilitation by prolong the abstinence time from 1~6 months to 1~3 years. However, it is an important issue that after a long period of forced abstinence, heroin addicts,s brain function whether will be improved, which is related to the long-term compulsory withdrawal whether can effectively promote heroin addicts to reduce the relapse rate.To solve these problems, this paper divided into the following three parts:(A) Data collection process and quality contro l in the f MRI Study of heroin addictswhen we collect magnetic resonance data of the brain in heroin addicts, the process is much complex and factors. So,the quality control is very important. Combined with the experience and failure of our study in the b rain functional neuroimaging from the data collection session QC lessons, i will focus on data collection methods and processes and quality control methods of data collection aspects from heroin addiction-related f MRI,such as T2 WI, resting state f MRI, high- resolution T1 WI, and strive to further optimize and standardize test processes and improve efficiency to ensure the accuracy of data collection.(B) Altered Brian Network C haracteristics in Heroin Addicts: a Resting-State f MRI StudyObjective: To explore changes in brain resting-state functional network in heroin addicts, identify the potential neuromechanism of heroin addiction from the perspective of brain network.Materials and Methods : Thirty heroin addicts(HA group) and twenty- nine healthy controls(HC group) underwent a resting-state f MRI. The whole-brain functional networks were constructed, the small-world properties(e.g. γ, λ) and node property(e.g. degree) were analyzed using graph theory. Using two sample t test in SPSS 19.0 to process the small- world properties and node property between HA group and HC group. The correlation between the dose of heroin use and the degree of node was analyzed by partial correlation analysis.Results: Compared with HC group, the small world charac teristics of HA group was altered(P<0.05, corrected by FDR); the degree of node in orbit frontal regions were increased, while, the degree of node in occipital brain regions were decreased(P <0.05, corrected by FDR). No correlation was found between the degree of node and the dose of heroin use.Conclusion: These results suggest that topology of functional brain networks altered in heroin addicts and which have a tendence to be the random networks. Increased motivational driving to the salience of drug and decresed visuospatial attention in heroin addicts may provide a new strategy for identifying the neuromechanism of heroin addiction.(C) Abstinent time effect on the brain small-world network characteristics in heroin addicts: a resting-state f MRI studyObjective: Protracted abstinence(PA) is one of the main treatment of heroin addicts in China. However, it is unclear that addicts brain function is improvement for extending the abstinence time. The study will explore heroin addicts brain on resting state f MRI in different abstinence time, and probe the curative effect of addiction abstinence time from the perspective of brain network.Materials and Methods : Sixteen heroin addicts from protracted abstinence in 11 months(PA11 group), twenty heroin addicts form protracted abstinence in 6 months(PA6 group) and thirty-one healthy controls(HC group) underwent a resting-state f MRI using 3.0T MRI scanner. Using graph theory to construct small- world network, calculate and compare three groups of small- world characteristics and the nodes degree in networks, analyze the correlation between the node degree and the abstinence time.Results: Compared with the HC group, the small world characteristic(λ) of PA11 group and the group PA6 were altered(P <0.05, FDR correction); decreased in the value of the node frontal brain region, the hippocampus, basal ganglia, temporal lobe and occipital lobe, etc.(P <0.05, LSD correction). T It was negatively correlated between he nodes degree of Parahippocampal gyrus and amygdala and the abstinence time(P <0.05).Conclusion: The brain network topology characteristics of PA11 group and PA6 group changed, and tended random network; The motivation, memory and craving of drugs and so were reduced. Even prolong the time of abstinence, addicts brain network topology is still abnormalities, may be exist relapse risks.In summary, topological properties of small- world network is abnormal in heroin addicts brain, drug motives capability increases. The brain function may be recovery in long term abstinence of heroin addicts. Prolonging abstinence time will reduce memory for drugs in heroin addicts, as well as for drugs motivation and craving, and promote abstinence. However, even the extended abstinence time, addicts brain is still in the network topology of structural abnormalities. |
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