Neuro-glial basis of phobia development

An aversive and therefore a stressful event can cause a long-lasting after-effect as seen in anxiety disorder. Although accumulating evidence demonstrated the mechanisms of aversive memory formation, how a stressful experience impacts the brain and generates the anxious state is largely unknown. Here, we show in Drosophila that one of the most stressful experiences, exposure to electric shocks, induces a long-lasting claustrophobia-like behaviour, a manifestation of anxious state. In contrast to shock-associated memory formation, development of claustrophobia does not require dopamine receptors. Our neuronal screening identified activation of a pair of Allatostatin A-releasing neurons being significant in claustrophobia development. Furthermore, transcriptome and behavioural analyses demonstrated that glial activation via Toll signalling is necessary and sufficient to induce claustrophobia. Thus, the stress-induced anxiety state is created, independently of aversive memory per se, through activation of a pair of neurons and glial activation, suggesting a model to explain the generalized anxiety state.