Functional MRI research of smoker's responses to smoking olfactory cue / 中国医学影像技术

ABSTRACT

Objective To detect different activated patterns of heavy smokers in different states as well as between smokers and non-smokers. Methods Seventeen subjects including 12 heavy smokers and 5 non-smokers (controls) were examined with functional magnetic resonance imaging (fMRI) performing smoking-related olfactory cue tasks. The data were processed with SPM2. These different patterns were compared between the two groups. Results When smokers were exposed to the smoking olfactory cue in the abstinent state, activation was found on the left superior frontal gyrus (BA8, 9, 10, 11), left middle frontal gyrus (BA8, 10, 11, 46), left inferior frontal gyrus (BA9), left medial frontal gyrus (BA6, 8, 10,11), right superior frontal gyrus (BA10), right middle frontal gyrus (BA8, 9), right inferior frontal gyrus (BA45, 47), right medial frontal gyrus (BA9, 11), left callosal gyrus (BA24, 31), right callosal gyrus (BA24, 37), right middle temporal gyrus (BA21) and both sides of the thalamus and cerebellum. When smokers were exposed to the smoking olfactory cue in the satiated state, activation could be found on both sides of the prefrontal lobe and cerebellar hemisphere, while there was no activation on the other brain regions. No activation was found on the whole brain of the nonsmokers,except for a little small volume active points appeared in individual subjects, possibly caused by the picture noise. Conclusion The Limbic system (cingulate cortex, thalamus) and the prefrontal lobe play an important role in the cue-induced smoking craving approved from the new perspective of the olfactory. It is feasible to research smoking addicts' brain activation and the role of neural mechanisms using olfactory stimulation with clinical 1.5T MRI equipment.