THURSDAY, Aug. 9 (HealthDay News) -- Leptin appears to modulate neural responses to visual food stimuli, leading to increased satiety and a diminished perception of how rewarding food will be, according to a study published online Aug. 9 in Science.
Sadaf Farooqi, M.D., of the University of Cambridge in the United Kingdom, and colleagues studied the effects of the hormone leptin on two patients -- a 14-year-old boy and 19-year-old girl -- with rare congenital leptin deficiency. Food intake was measured before and after seven days of leptin treatment. Researchers also presented the patients with visual images of food in a fasted and fed state and asked them to rate their hunger, satiety and perception of the food's desirability. Functional magnetic resonance imaging (fMRI) was used to monitor changes in brain activity associated with leptin.
Leptin treatment resulted in a major decrease in food intake. In addition, after leptin-replacement, subjects perceived food to be less rewarding and reported greater satiety after a meal. The fMRI showed changes in the ventral striatum of the brain associated with leptin, suggesting the hormone acts in that region.
"Our data support the notion that leptin acts on neural circuits governing food intake to diminish perception of food reward, while enhancing the response to satiety signals generated during food consumption," the authors conclude.
Abstract
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