Heroine Addicts Show Different FMRI Brain Activation Before And After Detoxification When Exposed To Drug-related Cues

Our study use BOLD-based fMRI (functional magnetic resonance imaging based on blood oxygenation level dependent) to detect the differential brain activity of heroin addicts for drug related cues before and after detoxification, and thus to explore how drug craving changes before and after detoxification.Fourteen active heroin users received the same experimental procedure for two times before and after detoxification. They first underwent a structural scan and then a functional scan. The design was a block design. In functional scan, they fixated a central cross for 30s before seeing one block of natural scene pictures (Neutral condition) which included 22 pictures presented every four seconds. Then it was the second condition (Drug condition), which included 30 drug-related pictures presented every four seconds. The Drug condition was followed by another block of Neutral condition with 22 pictures. All the stimuli are color pictures, and special attention was paid to match the brightness and colors of natural scene pictures and those of drug-related pictures. Brain activation was measured during presentation of visual stimuli. By contrasting the different brain activation by two kinds of pictures, brain activity underlying heroin craving could be detected.All subjects' average value of BOLD fMRI signal changes and its activation intensity was indicated with false colors, and covered to their relative structural images. The results show different brain activation before and after detoxification during exposure to neutral pictures and drug-related pictures. Before detoxification, drug-related cues activated right inferior frontal gyrus (Brodmann44/45 , 2624 mm~3) , left inferior frontal gyrns (Brodmann44/45 , 2688 mm~3) , left vision cortex (Brodmann18 ,1600 mm~3), right fusiform gyrus(Brodmann19 ,1536 mm~3) , left fusiform gyrus (Brodmann19 , 3968 mm~3) and cerebellum ( 10176 mm~3); after detoxification, drug-related cues did not elicit neural activity at standard threshold ,but at reduced threshold, drug-related cues still activated those brain regions observed before detoxification, but with smaller activation volume and lower intensity. We can infer that prefrontal cortex is essential to heroin craving, and cerebellem also play an important role for...