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Objective To explore the changes of functional connectivity of the prefrontal cortex in chronic heroin addicts under resting-state functional MRI (fMRI). Methods Resting fMRI examination was performed on 13 chronic heroin addicts and 14 healthy volunteers. After pre-processing the resting-state fMRI data, the prefrontal cortex was selected as the seed region, with which a whole-brain voxel temporal correlation in Iow frequency fMRI fluctuations was analyzed and the changes of functional connectivity of the prefrontal lobe in both chronic heroin addicts and healthy volunteers were calculated with SPM5 software. Results Compared with that in the control group, the functional connectivity between the left prefrontal cortex and the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus, right precuneus in the heroin addiction group was significantly decreased. The functional connectivity between the right prefrontal cortex and the left orbital frontal cortex, left middle frontal gyrus in thc heroin addiction group was also significantly decreased as compared with that in the control group. Conclusion Functional connectivity of prefrontal cortex in chronic heroin addicts decreases, indicating that the prefrontal cortex may be involved in the maintenance of heroin addiction and relapse after withdrawal.
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Objective To explore the reaction patterns of impulsiveness and risk-taking decision-making in heroin addicts and their significance.Methods Seventeen heroin addicts(HA group)admitted to Detoxification and Rehabilitation Center of Anhui Province from July 2010 to December 2010 and 18 healthy controls(HC group)recruited at the same period were performed Iowa gambling task(IGT)and Risky-Gains task(RGT),respectively; the different capacities of impulsiveness control and risk-taking decision-making between HA group and HC group were compared.Results As for IGT,decision-making course affected the net scores remarkably in HC group,whereas contrary result was observed in HA group(P＜0.05); no statistical difference between the numbers of low-frequency punishment cards and high-frequency punishment cards which subjects selected was noted in HA group,while statistical difference was observed in HC group(P＜0.05).Furthermore,the difference between the number of low-frequency punishment cards and high-frequency punishment cards in HC group was higher than that in HA group(P＜0.05).In RGT,as compared with risky response rate before punishment,risky response rate after punishment declined notably in HC group,while no significant changes were seen in HA group; risky response rate after reward and after punishment in HA group were significantly higher than those in HC group(P＜0.05).Conclusion As evidence of chronic heroin addicts' behavior,heroin addict exsits impulsiveness and deficit in risk-taking decision-making,which may be one of the causes of generation and maintenance of heroin addiction.
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Objective To explore the functional location of brain regions related to internet game addiction using clue-reaction model and functional magnetic resonance imaging (fMRI). Methods Twenty participants with internet game addiction and 20 control subjects without addiction were tested. They were presented with different internet game videos and the paired common life videos while undergoing fMRI. Questionnaire survey was employed to investigate their emotion changes after watching the game video; the activation data produced by the stimulations were collected through the measurement of blood-oxygen-level dependent signals in the brain. Subtraction algorithm was adopted to analyze the corresponding regions of interest. The activated brain areas stimulated by the internet game videos were determined. Results Compared with the common life video watching, the interact game video watching showed significantly different results of psychological assessments, including emotional states, degree of thirst, degree of liking and wishing to re-watch in the addiction group (P<0.05); while the interact game video watching only had a strong degree of re-watching as compared with the common life video watching in the control group. As compared with the common life videos, internet game videos could induce significantly high activation in the parietal lobe and visual cortex of the temporal lobe of the left brain region in the control group (P<0.05);while significantly activation of all the brain regions, except the nucleus accumbens and the caudate nucleus of the left brain region, was found in the internet game video watching as compared with those in the common life video watching in the addiction group (P<0.05). Conclusion The regions of brain activation of the internet game addiction can be determined by fMRI and these areas may be involved in the generation and maintenance of the internet game addiction.
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Objective To investigate the brain areas having functional connectivity with nucleus accumbens in heroin addicts with resting-state functional magnetic resonance imaging (fMRI), and explore the reward system of heroin addiction. Methods Fifteen participants with heroin addiction,voluntarily admitted to our drug rehabilitation center from June 2009 to March 2010, and 15 healthy controls at the same period were chosen in our study. Resting-state fMRI was performed on these patients; and then, the resting-state brain functional connectivity was also concluded by analyzing the left and right nucleus accumbens selected as regions of interests (ROIs). The corresponding brain areas having functional connections with ROIs were defined in the resting-state and the changes of functional connectivity were observed in heroin addicts. Results In the addiction group, the areas having functional connectivity with double nucleus accumbens included bilateral thalamus, the basal ganglia, the hippocampus, the midbrain and contralateral nucleus accumbens; and anterior cingulate cortex was also significantly correlated with left nucleus accumbens. However, in the control group, only the hippocampus and contralateral nucleus accumbens had these connection and their activity was much weaker than that in the addiction group. Conclusion In the resting-state, reward system of heroin addiction is constituted by the brain areas having functional connectivity with nucleus accumbens. And fMRI can be used to study the functional connections between the brain areas related to the heroin addiction from neuroimaging perspectives.
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Objective To study the relationship between the biological behavior of gliomas and the state of adjacent fiber tract. Methods Regular MRI and DTI were performed in 24 patients with histologically confirmed brain gliomas. The fiber tracts adjacent gliomas reconstructed with 3-dimensional, the state of fiber tracts were evaluated with displaced, infiltrated or destroyed. Reflection the infiltration of glioma of MMP-9 、CD44 and the proliferative activity of VEGF and Ki-67 expression were evaluated by SP immunohistochemical staining method in surgical specimens. Results The expression of VEGF or Ki-67 was higher in high grade gliomas than low grade (P＜0.05) and a negative correlation (P＞0.05) between MMP-9 or CD44 expression and the grade of gliomas was found. The states of fiber tracts were damaged greatly in the periphery of high grade gliomas than low grade (P＜0.05).Further, the states of fiber tracts were destroyed heavily in the periphery of gliomas that had higher expression of VEGF or Ki-67 (P＜0.05). But there were poor correlation (P＞0.05) between MMP-9 or CD44 expression and the state of fiber tracts adjacent to gliomas. Conclusions The grade of and proliferation of gliomas can influence the state of fiber tracts in the periphery of gliomas but the infiltration did not. It was helpful to estimate the biological behavior of gliomas on imagines and useful in deciding the therapeutic regimen.