What does brain activity look like when an animal is in a particular mental state, such as thirst, hunger or satiety, and how does the shift between different states occur? As the mammalian brain is of dazzling complexity and as no techniques allow observing the full mammalian brain at the speed of neuronal activity, we start with a much smaller and simpler organism: the fruit fly.
Most studies of brain activity in flies so far have aimed at identifying single neurons specifically involved in some behavior. In contrast, our approach is to image the activity of the whole brain, studying how brain regions interact and the role of subnetworks which span the whole brain such as the dopaminergic network. As the time resolution of activity sensors increases, classical techniques, such as confocal or 2 photon microscopy, become too slow to capture the activity of the whole brain because of prohibitive scanning times. My goal is thus to use newly developed techniques such as light field microscopy or multifocus microscopy to capture the activity in 3 dimensions as fast as possible, to understand how the activity flows in the Drosophila brain.