Starvation enhances olfactory sensitivity that encourage animals to search for food. the molecular mechanisms that enable sensory neurons to remain flexible and adapt to a particular internal state remain poorly understood. Here, we study the roles of GABA and insulin signaling in starvationdependent modulation of olfactory sensory neuron (oSn) function in the Drosophila larva. We show that GABA B-receptor and insulin-receptor play important roles during oSn modulation. Using an OSN-specific gene expression analysis, we explore downstream targets of insulin signaling in OSNs. our results suggest that insulin and GABA signaling pathways interact within oSns and modulate oSn function by impacting olfactory information processing. We further show that manipulating these signaling pathways specifically in the OSNs impact larval feeding behavior and its body weight. these results challenge the prevailing model of oSn modulation and highlight opportunities to better understand oSn modulation mechanisms and their relationship to animal physiology.

38Starvation enhances olfactory sensitivity that encourage animals to search for food. The 39 molecular mechanisms that enable sensory neurons to remain flexible and adapt to a particular 40 internal state remain poorly understood. Here, we study the roles of GABA and insulin signaling 41 in starvation-dependent modulation of olfactory sensory neuron (OSN) function in the 42Drosophila larva. We show that GABAB-receptor and insulin-receptor are necessary for OSN 43 modulation. Using a novel OSN-specific gene expression analysis, we explore downstream 44 targets of insulin signaling in OSNs. Our results strongly suggest that insulin and GABA 45 signaling pathways interact within OSNs and modulate OSN function by impacting olfactory 46 information processing and neurotransmission. We further show that manipulating these 47 signaling pathways specifically in the OSNs impact larval feeding behavior and its body weight. 48These results challenge the prevailing model of OSN modulation and highlight opportunities to 49 better understand OSN modulation mechanisms and their relationship to animal physiology. 50 51