Nutrient sensing in the larval brain
Final Report Abstract
Behavioral flexibility is an essential trait for survival of any organism. For example, choosing an appropriate food source is vital. To do so, the food’s nutritive value needs to be evaluated. Several studies have demonstrated that Drosophila melanogaster larvae and adults, as mammals, are able to distinguish between nutritious and non-nutritious carbohydrates independent of their taste. Several groups of neurons have been implicated in postprandial sugar sensing in adult flies. In larvae, neurons expressing Gr43a, a fructose receptor, have been shown to be implicated in postingestive glucose sensing. How can a fructose sensor mediate glucose sensing? We show that postingestive glucose, and also sorbitol, sensing takes place within the nervous system, since efficient carbohydrate uptake into the nervous system is a prerequisite. Within the nervous system carbohydrates are converted into fructose via the polyol pathway in glial cells. Glia-derived fructose is subsequently sensed via Gr43a expressed in neurons. Gr43a-expressing neurons signal via the neuropeptide Coranzonin to downstream neurons to induce behavioral adaptation. Thus, in postingestive nutrient sensing, the glial cells play a central role in information processing and regulation of behaviour.
Publications
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Plasticity of Carbohydrate Transport at the Blood-Brain Barrier. Frontiers in Behavioral Neuroscience, 14.
McMullen, Ellen; Weiler, Astrid; Becker, Holger M. & Schirmeier, Stefanie
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An essential role for glial cells in postingestive nutrient sensing.
Kulshrestha, Divita; Koch, Charlotte; Khalilov, Majid & Schirmeier, Stefanie
