Activation in mesolimbic and visuospatial neural circuits elicited by smoking cues: evidence from functional magnetic resonance imaging.
OBJECTIVE
The authors sought to increase understanding of the brain mechanisms involved in cigarette addiction by identifying neural substrates modulated by visual smoking cues in nicotine-deprived smokers.


METHODS
Event-related functional magnetic resonance imaging (fMRI) was used to detect brain activation after exposure to smoking-related images in a group of nicotine-deprived smokers and a nonsmoking comparison group. Subjects viewed a pseudo-random sequence of smoking images, neutral nonsmoking images, and rare targets (photographs of animals). Subjects pressed a button whenever a rare target appeared.


RESULTS
In smokers, the fMRI signal was greater after exposure to smoking-related images than after exposure to neutral images in mesolimbic dopamine reward circuits known to be activated by addictive drugs (right posterior amygdala, posterior hippocampus, ventral tegmental area, and medial thalamus) as well as in areas related to visuospatial attention (bilateral prefrontal and parietal cortex and right fusiform gyrus). In nonsmokers, no significant differences in fMRI signal following exposure to smoking-related and neutral images were detected. In most regions studied, both subject groups showed greater activation following presentation of rare target images than after exposure to neutral images.


CONCLUSIONS
In nicotine-deprived smokers, both reward and attention circuits were activated by exposure to smoking-related images. Smoking cues are processed like rare targets in that they activate attentional regions. These cues are also processed like addictive drugs in that they activate mesolimbic reward regions.
Due
Deborah L
DL
Department of Psychological and Brain Sciences, Duke University, Durham, NC 27709, USA.
Huettel
Scott A
SA
Hall
Warren G
WG
Rubin
David C
DC
D000328:Adult; D001288:Attention / Q000502:physiology; D016739:Behavior, Addictive / Q000175:diagnosis* / Q000523:psychology; D001921:Brain / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D003463:Cues; D004298:Dopamine / Q000502:physiology; D005260:Female; D006801:Humans; D008032:Limbic System / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D012201:Reward; D012907:Smoking / Q000523:psychology*; D013028:Space Perception / Q000502:physiology; D014029:Tobacco Use Disorder / Q000175:diagnosis* / Q000523:psychology; D014796:Visual Perception / Q000502:physiology*
D004298:Dopamine