Network Analysis of Intrinsic Functional Brain Connectivity in Male and Female Adult Smokers: A Preliminary Study

Sex Differences in Alterations of Brain Functional Network in Tobacco Use Disorder

INTRODUCTION

Many studies have found sex differences in alterations of brain function in cigarette-smoking adults from the perspective of functional activity or connectivity. However, no studies have systematically found different alteration patterns in brain functional topology of cigarette-smoking men and women from three perspectives: nodal and network efficiency and modular connections.

AIMS AND METHODS

Fifty-six tobacco use disorder (TUD) participants (25 women) and 66 non-TUD participants (28 women) underwent a resting-state functional magnetic resonance imaging scan. The whole-brain functional networks were constructed, and a two-way analysis of covariance with false discovery rate correction (q < 0.05) was performed to investigate whether men and women TUD participants had different alterations in the topological features at global, modular, and nodal levels.

RESULTS

Compared to non-TUD participants, men but not women TUD participants showed significantly lower global efficiency (lower intermodular connections between the visual and executive control and between the visual and subcortical modules did not pass the correction) and significantly lower nodal global efficiency in the right superior occipital gyrus, bilateral fusiform gyrus, the right pallidum, right putamen, the bilateral paracentral lobule, the postcentral gyrus, and lower nodal local efficiency in the left paracentral lobule.

CONCLUSIONS

Men and women TUD participants have different topological properties of brain functional network, which may contribute to our understanding of neural mechanisms underlying sex differences in TUD.

IMPLICATIONS

Compared to non-TUD participants, we found men but not women TUD participants with significantly lower network metrics at global, modular, and nodal levels, which could improve our understanding of neural mechanisms underlying sex differences in TUD and lay a solid foundation for future sex-based TUD prevention and treatment.

Altered executive control network and default model network topology are linked to acute electronic cigarette use: A resting-state fNIRS study

In recent years, electronic cigarettes (e-cigs) have gained popularity as stylish, safe, and effective smoking cessation aids, leading to widespread consumer acceptance. Although previous research has explored the acute effects of combustible cigarettes or nicotine replacement therapy on brain functional activities, studies on e-cigs have been limited. Using fNIRS, we conducted graph theory analysis on the resting-state functional connectivity of 61 male abstinent smokers both before and after vaping e-cigs. And we performed Pearson correlation analysis to investigate the relationship between alterations in network metrics and changes in craving. E-cig use resulted in increased degree centrality, nodal efficiency, and local efficiency within the executive control network (ECN), while causing a decrease in these properties within the default model network (DMN). These alterations were found to be correlated with reductions in craving, indicating a relationship between differing network topologies in the ECN and DMN and decreased craving. These findings suggest that the impact of e-cig usage on network topologies observed in male smokers resembles the effects observed with traditional cigarettes and other forms of nicotine delivery, providing valuable insights into their addictive potential and effectiveness as aids for smoking cessation.

Oxytocin-Induced Changes in Intrinsic Network Connectivity in Cocaine Use Disorder: Modulation by Gender, Childhood Trauma, and Years of Use

Cocaine use disorder (CUD) is a major public health concern with devastating social, economic, and mental health implications. A better understanding of the underlying neurobiology and phenotypic variations in individuals with CUD is necessary for the development of effective and targeted treatments. In this study, 39 women and 54 men with CUD completed a 6-min resting-state functional magnetic resonance imaging scan after intranasal oxytocin (OXY) or placebo administration. Graph-theory network analysis was used to quantify functional connectivity changes caused by OXY in striatum, anterior cingulate cortex (ACC), insula, and amygdala nodes of interest. OXY increased connectivity in the right ACC and left amygdala in males, whereas OXY increased connectivity in the right ACC and right accumbens in females. Machine learning was then used to associate treatment response (placebo minus OXY) in nodes of interest with years of cocaine use and severity of childhood trauma separately for males and females. Childhood trauma and years of cocaine use were associated with OXY-induced changes in ACC connectivity for both men and women, but connectivity changes in the amygdala were associated with years of cocaine use in men and connectivity changes in the right insula were associated with years of cocaine use in women. These findings suggest that salience network nodes (ACC and insula) are potential OXY treatment targets in CUD, with the amygdala as a treatment target for men and the accumbens as a treatment target for women.