The interaction of oxytocin and nicotine addiction on psychosocial stress: an fMRI study

832 

Abstract Submission 

Jiecheng Ren¹, Zhengde Wei¹, Xiaochu Zhang¹

¹University of Science and Technology of China, Hefei, Anhui

Jiecheng Ren  
University of Science and Technology of China
Hefei, Anhui

Zhengde Wei  
University of Science and Technology of China
Hefei, Anhui

Xiaochu Zhang  
University of Science and Technology of China
Hefei, Anhui

The anxiolytic effect of oxytocin (OXT) on psychosocial stress has been well documented (Heinrichs M., 2003). However, there is still a need for further in-depth research to fully understand the mechanisms of OXT's effect on psychosocial stress (Takayanagi Y., 2021). Various factors, such as nicotine addiction, can interact with OXT's anxiolytic effect (Chen, F.S., 2011). Investigating the effects and interaction of OXT and nicotine addiction is essential in determining the effectiveness of OXT intervention for psychosocial stress, particularly for smokers. We assumed that functions of the overlapping brain areas of OXT's anxiolytic effect and nicotine addiction are essential for the effects and interaction of OXT and nicotine addiction.

Firstly, after intranasal administration of randomized OXT or placebo (saline), a group of healthy participants (n=27) and a group of smokers (n=26) completed the Montreal Imaging Stress Task (MIST) in an MRI scanner (Figure 1A, C, D). Secondly, a group of smokers (n=22) was recruited to complete a transcranial direct current stimulation (tDCS) experiment (Figure 1B), in which anodal tDCS was applied on subjects' anterior right superior temporal gyrus (rSTG). In both experiment, subjective stress ratings, salivary cortisol samples and the amount of daily cigarette consumption were obtained from each participant.

In first fMRI experiment, analysis of variance (ANOVA) revealed an interaction of OXT and nicotine addiction on subjective stress (Figure 2A). In smokers, OXT failed to suppress the elevation of subjective stress and craving ratings after psychosocial stress (Figure 2A, C), but successfully suppressed salivary cortisol level (Figure 2B). A voxel-wise ANOVA of fMRI data identified an interaction between OXT and nicotine addiction in the anterior right superior temporal gyrus (rSTG), medial frontal gyrus, right lentiform nucleus / inferior frontal gyrus, and right parahippocampal gyrus (Figure 2D). Among these regions, changes in anterior rSTG activity were found inversely associated with daily cigarette consumption after administration of PLC in smokers (Figure 2E), along with a correlation between activations of anterior rSTG and salivary cortisol (Figure 2F). We also found an interaction between OXT and nicotine addiction in anterior rSTG's functional connectivity with right middle frontal gyrus (Figure 2G). Correlation between this functional connectivity and subjective psychosocial stress was also found abnormal in smokers, in which nicotine addiction reversed the direction of the correlation, even after OXT administration (Figure 2H, I). In second tDCS experiment, we found that after tDCS on anterior rSTG, OXT was able to successfully suppress the elevation of subjective stress and craving ratings after psychosocial stress (Figure 2J, K, L).

In summary, our study provides novel behavioral and neural information on the effects and interaction of OXT and nicotine addiction on psychosocial stress. Our findings suggest that nicotine addiction blocks OXT's anxiolytic effect on psychosocial stress, which is related to abnormalities in the anterior right superior temporal gyrus, and its functional connectivity with right middle frontal gyrus. These findings will support further development on oxytocin's intervention of psychosocial stress in nicotine addiction, and provides essential information for indicating OXT's effectiveness.

Social Neuroscience Other ¹

Activation (eg. BOLD task-fMRI)

BOLD fMRI ²

FUNCTIONAL MRI

Other - psychosocial stress; intranasal oxytocin; psychosocial stress