Cellular and genetic bases of neural circuits evolution
Sensory systems encode the world around us to produce context-dependent appropriate behaviours. However, we know little about the way new sensory evoked behaviours arise as neural circuits are re-shaped during evolution. Tackling this question requires a deep understanding of the circuits underlying specific behaviours and integration of this knowledge with tools from other fields, including evolutionary and developmental biology. Recent technological advancements on neural circuit interrogation and genome editing have put progress on this fundamental biological question within reach. 
The olfactory system of the larval stage of the fly Drosophila melanogaster and related species is an ideal model for investigating these questions because (i) D. melanogaster has pioneered both the fields of population genetics and neurogenetics and (ii) its olfactory system is one of the best-characterised neural circuits. We will address the question of how olfactory circuits evolve by studying four species with divergent odour-guided behaviours through the following multidisciplinary aims:
1. Which olfactory pathways are targeted in the evolution of ecological specialisation? – Combining high-throughput behavioural assays, optogenetics and calcium imaging in the larva of all four species we will determine whether/which olfactory pathways have switched valences or sensitivity.
2. How have central neural circuits diverged? – We will address this question at unprecedented resolution through whole-brain calcium imaging and serial electron microscopy reconstruction.
3. What are the molecular and genetic bases of neural circuits rewiring during evolution? – Using transcriptomic profiling we will identify differentially expressed genes in conserved and divergent circuits across species, and functionally probe selected candidates to establish causality.
4. How do evolutionary forces shape olfactory circuits? – We will investigate this question using field studies and population genetics