The origins of individuality in the Drosophila visual system

Why are all brains different from each other and where does this variability come from? A plethora of animal experiments demonstrate the importance of environmental and genetic influence in creating behavioural variation. A third factor named stochastic developmental processes is less established. Despite recent advancements, a systematic review of variation in brain wiring, its origins, and behavioural consequences is still lacking. My main research goal is to understand the contributions of genetic, stochastic, and environmental factors to variation in brain wiring and behavioural individuality. Recently, I have shown that stochastic, non-heritable developmental processes can result in individually variable wiring diagrams that are associated with individual behavioural characteristics. This system provides a tractable genetic and neuronal model for individuality. Based on this work, I hypothesize that (1) stochastic developmental processes are a general neuronal property affecting synaptic distributions, wiring and behaviour, and (2) that stochastic wiring differences affect several behaviours ranging from visual guided responses to circadian activity patterns. Within this framework, I aim to answer two key questions on the origins of individuality:1. Is circuit variability a general nervous system property and what are its origins? 2. Does circuit variability contribute to other visual and non-visual behavioural paradigms?