Altered spontaneous activity in young chronic cigarette smokers revealed by regional homogeneity

Background: Few studies have been previously published about the resting state brain activity in young chronic smokers, although many previous fMRI studies have shown that the task-related activity pattern is altered in chronic smokers. Methods: In the present study, forty-five healthy smokers (age: 27.9 +/- 5.6 year) and forty-four healthy non-smoking control subjects (age: 26.3 +/- 5.8 year) have been imaged with functional magnetic resonance imaging (fMRI) and analyzed with the regional homogeneity (ReHo) approach. Results: Compared with healthy controls, decreased ReHo was found in smokers in the right inferior frontal cortex and increased ReHo was found in the left superior parietal lobe (P < 0.01, 35 Voxels, Alphasim corrected). Conclusions: Our data suggested that, during resting state, neural function is less synchronized in the right inferior frontal cortex and more synchronized in the left superior parietal lobe in chronic smokers compared to nonsmokers. The decreased synchronization in the right inferior frontal cortex may reflect lacking of control over reward-related behavior, and the increased synchronization may reflect smoking urges.