Pioneering study reveals brain effects of smoking using electronic cigarettes

The results of a new study  (published in the journal Scientific Reports) have demonstrated for the first time how the effects of “smoking” on the brain and nervous system can be monitored using functional MRI scanning.

Wall, M. B., Mentink, A., Lyons, G., Kowalczyk, O. S., Demetriou, L., & Newbould, R. D. (2017). Investigating the neural correlates of smoking: Feasibility and results of combining electronic cigarettes with fMRI. Scientific Reports, 7(1), 11352.

e cigarette study

Fig 1. Image from Wall et al. (2017) revealing the functional brain effects of ‘smoking’ for the first time. Higher activity (orange/yellow) is seen in primary motor cortex (reflecting the hand movements associated with smoking), but also in dopamine-rich reward regions (putamen, globus pallidus), and emotional/salience (amygdala, cingulate gyrus) related regions. Relative deactivation (blue) is seen in the ventral striatum and orbitofrontal cortex.

The team behind the research is from the international translational imaging centre, Imanova (now part of Invicro), based at Imperial College London's Hammersmith Hospital campus. Led by Head of MRI Applications, Dr Matt Wall, the study found that using e-cigarettes in an MRI environment has the potential to explore the regions of the brain involved in the sensory and behavioural aspects of smoking.

This exciting new feasibility study (which paves the way for larger, more in-depth controlled research programmes) will lead the way in a revolutionary approach to research on smoking using functional magnetic resonance imaging (fMRI). This project using e-cigarettes represents a promising new model for the study of smoking and the brain processes involved in addiction more generally.

In the past, it has been impossible to monitor these effects using conventional cigarettes or tobacco products due to the obvious limitations and safety issues associated with volunteers smoking in the confines of an MRI scanner. However, the nature of vaping products, allows neuroscientists to effectively record brain activity and stimulation with each “drag” of the e-cigarette.

Dr Wall explains; “The behavioural and sensory aspects of smoking are important factors in maintaining the addiction to cigarettes but their brain correlates have never been studied directly in humans. The practical and safety issues involved with using combustible materials in the confined MRI environment have effectively prevented serious neuroscientific work using modern methods.”

“However, electronic cigarettes obviate many of these practical problems and safety issues, and also provide a very good simulation of ‘traditional’ smoking. We have shown that using e-cigarettes with fMRI is an excellent paradigm for direct evaluation of the effects of smoking on human neurophysiology.”

He adds; “In this study, we saw significantly increased smoking-related activity in brain regions associated with motor responses, sensory functions (taste/flavour responses) and other brain areas often associated with processing of reward stimuli. This is the first time we’ve really been able to visualise exactly what happens in a smoker’s brain when they inhale on a cigarette.”

For the purpose of this study, a custom-built optical recording device was used to record the light output of the LED at the tip of the e-cigarette in order to log smoking onset, strength and duration. Physiological data (pulse oximetry, respiration) were also recorded and used to provide post-hoc correction of the fMRI data for physiological noise effects.

Imanova is a unique, advanced medical imaging Contract Research Organisation (CRO), with established, state-of-the-art molecular imaging techniques based on preparation of novel radiopharmaceuticals and supporting drug development and clinical trials. The imaging capabilities and approach of Imanova also offer a real benefit to a range of consumer health companies seeking to demonstrate product differentiation with scientific evidence in their respective markets.

Imanova’s CEO and Chairman, Kevin Cox, commented; “E-cigarettes are undergoing explosive growth in the market – coupled with intense professional, public and media debate – but are currently unregulated, largely due to a lack of evidence based research.

“Yet, smoking cessation products lend themselves to the MRI scanning techniques as they contain a known psychoactive substance, nicotine, which has clear, previously demonstrated effects on the brain and body. We therefore believe that the unique scanning capabilities demonstrated in this first study will provide both the industry and health campaigners with the information and intelligence they need to effectively govern legislation and substantiate claims.”