Acute exercise modulates cigarette cravings and brain activation in response to smoking-related images: an fMRI study.
BACKGROUND
Substances of misuse (such as nicotine) are associated with increases in activation within the mesocorticolimbic brain system, a system thought to mediate the rewarding effects of drugs of abuse. Pharmacological treatments have been designed to reduce cigarette cravings during temporary abstinence. Exercise has been found to be an effective tool for controlling cigarette cravings.


OBJECTIVE
The objective of this study is to assess the effect of exercise on regional brain activation in response to smoking-related images during temporary nicotine abstinence.


METHODS
In a randomized crossover design, regular smokers (n = 10) undertook an exercise (10 min moderate-intensity stationary cycling) and control (passive seating for same duration) session, following 15 h of nicotine abstinence. Following treatments, participants entered a functional Magnetic Resonance Imaging (fMRI) scanner. Subjects viewed a random series of smoking and neutral images for 3 s, with an average inter-stimulus-interval (ISI) of 10 s. Self-reported cravings were assessed at baseline, mid-, and post-treatments.


RESULTS
A significant interaction effect (time by group) was found, with self-reported cravings lower during and following exercise. During control scanning, significant activation was recorded in areas associated with reward (caudate nucleus), motivation (orbitofrontal cortex) and visuo-spatial attention (parietal lobe, parahippocampal, and fusiform gyrus). Post-exercise scanning showed hypo-activation in these areas with a concomitant shift of activation towards areas identified in the 'brain default mode' (Broadmanns Area 10).


CONCLUSIONS
The study confirms previous evidence that a single session of exercise can reduce cigarette cravings, and for the first time provides evidence of a shift in regional activation in response to smoking cues.
Janse Van Rensburg
Kate
K
School of Sport and Health Sciences, University of Exeter, St Luke's Campus, Exeter EX1 2LU, UK. kj214@exeter.ac.uk
Taylor
Adrian
A
Hodgson
Tim
T
Benattayallah
Abdelmalek
A
D000293:Adolescent; D000328:Adult; D016739:Behavior, Addictive / Q000503:physiopathology / Q000517:prevention & control* / Q000523:psychology; D001921:Brain / Q000503:physiopathology; D018592:Cross-Over Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012201:Reward; D012907:Smoking; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000517:prevention & control* / Q000523:psychology; D014029:Tobacco Use Disorder / Q000503:physiopathology / Q000523:psychology*; D055815:Young Adult