Investigating the neural correlates of smoking: Feasibility and results of combining electronic cigarettes with fMRI

Abstract

Cigarette addiction is driven partly by the physiological effects of nicotine, but also by the distinctive sensory and behavioural aspects of smoking, and understanding the neural effects of such processes is vital. There are many practical difficulties associated with subjects smoking in the modern neuroscientific laboratory environment, however electronic cigarettes obviate many of these issues, and provide a close simulation of smoking tobacco cigarettes. We have examined the neural effects of ‘smoking’ electronic cigarettes with concurrent functional Magnetic Resonance Imaging (fMRI). The results demonstrate the feasibility of using these devices in the MRI environment, and show brain activation in a network of cortical (motor cortex, insula, cingulate, amygdala) and sub-cortical (putamen, thalamus, globus pallidus, cerebellum) regions. Concomitant relative deactivations were seen in the ventral striatum and orbitofrontal cortex. These results reveal the brain processes involved in (simulated) smoking for the first time, and validate a novel approach to the study of smoking, and addiction more generally.

An Electronic Aerosol Delivery System for Functional Magnetic Resonance Imaging

“…Wall and colleagues found that five e-cig devices that were common at the time of the study did not pose safety concerns or negatively impact data quality during fMRI, suggesting that these barriers can be overcome by using smaller, first generation devices. 17 Despite this novel finding, no other studies known to our group have used e-cigs to measure brain function during fMRI. While the use of one e-cig device during fMRI is a leap forward in this area, studies aiming to compare and contrast different features of aerosols or various conditions, such as flavors or nicotine levels, are best conducted with the use of a controlled aerosol delivery system that delivers aerosols generated from different e-cigs during the same scanning session.…”

Neural bases of risky decisions involving nicotine vapor versus monetary reward

“…There are a number of differences in the neural responses to choices involving money vs. drug reward, and these have not been explored extensively in the literature previously. There is only one study, to the best of our knowledge, which had subjects consuming nicotine inside the fMRI scanner (Wall et al, 2017). However, that study consisted of ad-libitum and cued smoking inside the scanner and was not designed to inform about the choice behavior in terms of risk-taking tendencies and the neural correlates of different aspects of decision making about nicotine in nicotine dependent subjects.…”

“…Several studies have shown greater activation of ACC and mPFC when viewing smoking cues as compared to neutral cues (Hartwell et al, 2011;Wilson et al, 2005). Wall et al (2017) showed increased activation of Insula and dorsal ACC (dACC) in cued smoking as compared to ad-libitum smoking. In this respect, we also found a region in the cingulate cortex that showed an interaction of the effect of self-reported craving and loss minus win in the nicotine sessions; however, this was only a small region.…”

A Methodological Checklist for fMRI Drug Cue Reactivity Studies: Development and Expert Consensus

“…Studies where a substance is directly administered (usually in small amounts) remain relatively rare in the field of FDCR as a whole. However, given the popularity of these paradigms in some fields (such as in tobacco use disorder and alcohol use disorder) and the large variety of substance delivery mechanisms used, it is recommended that researchers describe their delivery mechanisms in detail and cite the relevant literature when possible (Lindsey et al, 2013; J. P. Schacht, Anton, & Myrick, 2013; Wall et al, 2017). Prior exposure of participants to cues is also important.…”