During the last two decades, the prevalence of obesity has dramatically increased in western and westernized societies. Its devastating health consequences include hypertension, cardiovascular diseases, or diabetes and make obesity the second leading cause of unnecessary deaths in the USA. As a consequence, obesity has a strong negative impact on the public health care systems. Recently emerging scienti?c insight has helped understanding obesity as a complex chronic disease with multiple causes. A multileveled gene-environment interaction appears to involve a substantial number of susceptibility genes, as well as associations with low physical activity levels and intake of high-calorie, low-cost, foods. Unfor- nately, therapeutic options to prevent or cure this disease are extremely limited, posing an extraordinary challenge for today's biomedical research community. Obesity results from imbalanced energy metabolism leading to lipid storage. Only detailed understanding of the multiple molecular underpinnings of energy metabolism can provide the basis for future therapeutic options. Numerous aspects of obesity are currently studied, including the essential role of neural and endocrine control circuits, adaptive responses of catabolic and anabolic pathways, metabolic fuel sensors, regulation of appetite and satiation, sensory information processing, transcriptional control of metabolic processes, and the endocrine role of adipose tissue. These studies are predominantly fuelled by basic research on mammalian models or clinical studies, but these ?ndings were paralleled by important insights, which have emerged from studying invertebrate models.

The sense of smell has an essential role in locating food, detecting predators, navigating, and communicating social information. Accordingly, the olfactory system has evolved complex repertoires of receptors to face these problems. Although the sense of taste has less far-reaching tasks, they are every bit as essential for the animals well-being, allowing it to reject toxic materials and to select nutritionally valuable food. The last decade has seen a massive advance in understanding the molecular logic of chemosensory information processing, beyond that already achieved in the rst few years following Linda Bucks discovery of odorant receptors. Shortly afterwards, the major principles of olfactory representation had been established in mammals as the one neuron/ one receptor rule and the convergence of neurons, which express the same receptor, onto individual modules in the olfactory bulb. In recent years, such studies have been extended to lower vertebrates, including shes and other phyla, i. e. , arthropods, worms, and insects, showing both the general validity of these concepts and some exceptions to the rule. In parallel, hallmarks of the molecular logic of taste sensation have been deciphered and found to differ in interesting ways from those of smell sensation.

During the last two decades, the prevalence of obesity has dramatically increased in western and westernized societies. Its devastating health consequences include hypertension, cardiovascular diseases, or diabetes and make obesity the second leading cause of unnecessary deaths in the USA. As a consequence, obesity has a strong negative impact on the public health care systems. Recently emerging scienti?c insight has helped understanding obesity as a complex chronic disease with multiple causes. A multileveled gene-environment interaction appears to involve a substantial number of susceptibility genes, as well as associations with low physical activity levels and intake of high-calorie, low-cost, foods. Unfor- nately, therapeutic options to prevent or cure this disease are extremely limited, posing an extraordinary challenge for today's biomedical research community. Obesity results from imbalanced energy metabolism leading to lipid storage. Only detailed understanding of the multiple molecular underpinnings of energy metabolism can provide the basis for future therapeutic options. Numerous aspects of obesity are currently studied, including the essential role of neural and endocrine control circuits, adaptive responses of catabolic and anabolic pathways, metabolic fuel sensors, regulation of appetite and satiation, sensory information processing, transcriptional control of metabolic processes, and the endocrine role of adipose tissue. These studies are predominantly fuelled by basic research on mammalian models or clinical studies, but these ?ndings were paralleled by important insights, which have emerged from studying invertebrate models.

The sense of smell has an essential role in locating food, detecting predators, navigating, and communicating social information. Accordingly, the olfactory system has evolved complex repertoires of receptors to face these problems. Although the sense of taste has less far-reaching tasks, they are every bit as essential for the animals well-being, allowing it to reject toxic materials and to select nutritionally valuable food. The last decade has seen a massive advance in understanding the molecular logic of chemosensory information processing, beyond that already achieved in the rst few years following Linda Bucks discovery of odorant receptors. Shortly afterwards, the major principles of olfactory representation had been established in mammals as the one neuron/ one receptor rule and the convergence of neurons, which express the same receptor, onto individual modules in the olfactory bulb. In recent years, such studies have been extended to lower vertebrates, including shes and other phyla, i. e. , arthropods, worms, and insects, showing both the general validity of these concepts and some exceptions to the rule. In parallel, hallmarks of the molecular logic of taste sensation have been deciphered and found to differ in interesting ways from those of smell sensation.