Food-Related Odor Probes of Brain Reward Circuits During Hunger: A Pilot fMRI Study

Authors

  • Veronique Bragulat,

    1. Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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  • Mario Dzemidzic,

    1. Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA
    2. Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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  • Carolina Bruno,

    1. Division of Endocrinology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
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  • Cari A. Cox,

    1. Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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  • Thomas Talavage,

    1. Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
    2. School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA
    3. Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA
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  • Robert V. Considine,

    Corresponding author
    1. Division of Endocrinology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
      (rconsidi@iupui.edu)
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  • David A. Kareken

    Corresponding author
    1. Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA
    2. Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
    3. Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
      (dkareken@iupui.edu)
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(dkareken@iupui.edu)

(rconsidi@iupui.edu)

Abstract

Food aromas can be powerful appetitive cues in the natural environment. Although several studies have examined the cerebral responses to food images, none have used naturalistic food aromas to study obesity. Ten individuals (five normal-weight and five obese) were recruited to undergo 24 h of food deprivation. Subjects were then imaged on a 3T Siemens Trio-Tim scanner (Siemens, Erlangen, Germany) while smelling four food-related odors (FRO; two sweet odors and two fat-related) and four “nonappetitive odors” (NApO; e.g., Douglas fir). Before the imaging session, subjects rated their desire to eat each type of food to determine their most preferred (P-FRO). Across all 10 subjects, P-FRO elicited a greater blood oxygenation level dependent (BOLD) response than the NApO in limbic and reward-related areas, including the bilateral insula and opercular (gustatory) cortex, the anterior and posterior cingulate, and ventral striatum. Obese subjects showed greater activation in the bilateral hippocampus/parahippocampal gyrus, but lean controls showed more activation in the posterior insula. Brain areas activated by food odors are similar to those elicited by cues of addictive substances, such as alcohol. Food odors are highly naturalistic stimuli, and may be effective probes of reward-related networks in the context of hunger and obesity.

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