Neuroimaging-Verfahren in der Adipositasforschung

Neuroimaging Technology in Obesity Research. Neurological correlates of obesity have been extensively discussed and investigated over the last few years. Use of neuroimaging technology provides novel approaches to obesity research. Among these, magnetic resonance imaging (MRI) and positron emission tomography (PET) appear to be most promising. Due to the great variability of confounding factors on brain development many selection criteria have to be fulfilled in order to assure the reliability of a neuroimaging study. The number of highly capable MRI and PET investigation centers is increasing, especially in large urban areas where highly characterized cohorts of subjects can be recruited. Recent investigations have shown that the human brain receives and distributes homeostatic and hedonic impulses to regulate eating behavior. Both hunger and appetite are distinct aspects of the drive to eat originating in different brain areas, yet subject to a common regulating center. The responsible areas appear to be structurally and functionally altered in obesity, including changes in the reward system. Women and men (both lean and obese) seem to respond differentially to homeostatic and hedonic stimuli for hunger and satiety. The “hunger networks” are affected by genetic, biochemical, hormonal, neuronal, and other factors. For example ghrelin, peptide YY, and leptin are claimed to be endocrine signals from the gastrointestinal tract and adipose tissue not only regulating metabolic activity and nutrient distribution but also possessing central nervous effects. These hormones act as short-time or long-time modulators of specific brain areas with homeostatic or hedonic power on food evaluation and eating behavior. Knowing the interactions of certain brain regions in the regulation of hunger/appetite and satiety/satiation will allow for the development of new therapeutic agents against obesity. J Klin Endokrinol Stoffw 2011; 4 (Pre-Publishing Online).