The research of my group aims to understand how odor tracking (chemotaxis) comes about in terms of neural-circuit computations. We tackle this problem in the fruit fly Drosophila melanogaster larva, which possesses fewer than 10,000 neurons organized in a central brain. Using a combination of computational and experimental methods that include high-resolution behavioral analysis, electrophysiology and optogenetics, we follow an integrative approach to model the algorithms that direct navigation in odor gradients and to unravel the neural implementation of these algorithms. We are seeking to map and to functionally characterize the neural circuits participating in the conversion of olfactory information into navigational decisions. Our long-term goal is to conduct a comparative analysis of the neural-circuit computations underlying differences in chemotactic behaviors in the Drosophila group. We believe that understanding how perceptual decision-making is organized in a small insect brain will provide conceptual building blocks to study similar processes in higher-order organisms.