Animal behavior needs to be flexible and adaptive to changes in the environment, but behavioral decisions also need to take changing internal demands into account. Environmental factors such as incoming predators can trigger escape behaviors, for example, while internal demands, like hunger, can increase food-searching behavior. To achieve appropriate behavioral selection under various, complex conditions, multiple sensory inputs must be received and integrated by neuronal circuits in the brain in a context-dependent manner.
Stefan is studying this context-dependent integration of sensory stimuli by neural circuits and the resulting behavioral responses. He is focusing on descending neurons, which play a major role in eliciting behaviors by controlling and modulating activity pattens in motor networks of the ventral nerve cord (the analogue to the vertebrate spinal cord). In certain behaviors, such as landing, these neurons are gated by the behavioral state of the fly. If the fly is in a state where landing is inappropriate the neurons controlling landing are decoupled from visual stimuli thereby preventing undesired behavioral responses. To elucidate whether state-dependent modulation of descending neurons is a general mechanism mediating action selection, and how this modulation is achieved, Stefan uses in vivo whole-cell patch clamp recordings combined with optogenetic tools and behavioral analysis.
Stefan holds a B.Sc in Applied Biology from the University of Applied Sciences Bonn Rhein-Sieg and a M.Sc in Life and Medical Sciences from the University Bonn. He did his PhD in the group of Prof. Kittel at the Institute of Animal Physiology. His thesis focused on metabotropic mechanosensation in chordotonal organs of Drosophila larvae.