Altered subcallosal and posterior cingulate cortex-based functional connectivity during smoking cue and mental simulation processing in smokers

Abstract

BackgroundLong-term cigarette smoking induces sensitization of incentive salience and conditioning of contextual cues which involves brain function alteration across multiple regions. Understanding how nicotine affects hub-based functional connectivities involved in affective and cognitive function can help us determine the treatment strategy for nicotine dependence. MethodFunctional MRI was conducted on 30 smokers and 30 non-smokers while mentally simulating neutral and smoking hand movements. Smoking cue and mental simulation processing-related changes in functional connectivity strengths of the subcallosal and posterior cingulate cortex (SCC and PCC) with major brain network nodes were examined. ResultsCompared to non-smokers, smokers showed cue-induced SCC functional connectivities which were enhanced with the intraparietal sulcus and reduced with the medial prefrontal cortex. The PCC activation and functional connectivity enhancements with the anterior insula cortex and rostro-lateral prefrontal cortex was found during smoking mental simulation. The PCC-lateral prefrontal cortex functional connectivity correlated with nicotine dependence severity. ConclusionThe present results demonstrate that smokers can be identified by cue-induced SCC functional connectivity strength decline and increment in the default mode and dorsal attention network nodes. However, nicotine dependence was associated with smoking mental simulation-related PCC-lateral prefrontal cortex functional connectivity strength, suggesting that the development of nicotine dependence may depend on the strength of coupling between the default mode network and the central executive network at the cognitive level.