Functional connectivity of nucleus accumbens in heroin addicts: a resting-state fMRI study

Abstract

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. Key words: Behavior, addiction; Heroin; Nucleus accumbens; MRI