Elsevier, NeuroImage, 1(52), p. 284-289
DOI: 10.1016/j.neuroimage.2010.03.086
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Overweight and obesity is a health threat of increasing concern and understanding the neurobiology behind obesity is instrumental to the development of effective treatment regimes. Serotonergic neurotransmission is critically involved in eating behaviour; cerebral level of serotonin (5-HT) in animal models is inversely related to food intake and body weight and some effective anti-obesity agents involve blockade of the serotonin transporter (SERT). We investigated in 60 healthy volunteers body mass index (BMI) and regional cerebral SERT binding as measured with [11C]DASB PET.In a linear regression model with adjustment for relevant covariates, we found that cortical and subcortical SERT binding was negatively correlated to BMI (-0.003 to -0.012 BPND unit per kg/m2). Tobacco smoking and alcohol consumption did not affect cerebral SERT binding.Several effective anti-obesity drugs encompass blockade of the SERT; yet, our study is the first to demonstrate an abnormally decreased cerebral SERT binding in obese individuals. Whether the SERT has a direct role in the regulation of appetite and eating behaviour or whether the finding is due to a compensatory downregulation of SERT secondary to other dysfunction(s) in the serotonergic transmitter system, such as low baseline serotonin levels, remains to be established. © 2010 Elsevier Inc.