Smoking Progression and Nicotine-Enhanced Reward Sensitivity Predicted by Resting-State Functional Connectivity in...

Area of Science:

• Neuroscience
• Addiction Research
• Neuroimaging

Background:

• Individual differences in nicotine-enhanced reward sensitivity (NERS) and smoking progression are not well understood.
• Research is needed to understand the neural basis of these differences in young light smokers.

Purpose of the Study:

• Investigate if resting-state functional connectivity (rsFC) during nicotine abstinence predicts NERS and smoking progression.
• Hypothesize that high rsFC between specific brain regions (insula, ACC, hippocampus, thalamus, NAcc, PFC) would predict NERS and smoking progression.

Main Methods:

• 64 young light smokers (18-24 years) with 5-35 cigarettes/week use underwent fMRI after 14 hours of nicotine deprivation.
• Participants completed a probabilistic reward task after placebo and regular cigarette administration on separate days.

Main Results:

• Greater NERS correlated with increased rsFC between the right anterior PFC and right NAcc.
• Reduced rsFC between the ACC and left inferior prefrontal gyrus, and insula and ACC, was observed.
• Decreased rsFC within the salience network (ACC and insula) predicted increased smoking progression over 18 months and greater NERS.

Conclusions:

• First evidence linking rsFC differences in young light smokers to NERS and smoking progression.
• Weaker salience network rsFC predicts greater NERS and smoking progression.
• Salience network rsFC and drug-enhanced reward sensitivity may serve as potential endophenotypes for addiction research.