Characterizing the Sensorimotor Transformation in Drosophila olfactory system Understanding how the nervous system transforms sensory inputs into motor commands is a fundamental question in neuroscience. To understand how the nervous system performs these complex sensorimotor transformations we must be able to provide a well-controlled stimulus that elicits complex, multisequence behaviors and a means to quantitatively analyze this behavior, as well as have a complete knowledge of the underlying neural circuitry involved in this behavior. Here, we look to characterize the sensorimotor transformation occurring within two olfactory receptor neuron (ORN) classes in Drosophila melanogaster and identify how they impact behavior. Using an electron micrograph dataset of the fly brain we can identify the connection patterns between the first-order neurons of the olfactory system and the downstream second- and third-order neurons. The fly is highly tractable and we will use genetic strategies to optogenetically activate this first-order ORN classes and record from the second- and third- order neurons in response to this activation. By observing fly behavior in response to this ORN activation we can determine the relationship between its selective activation and its impact on behavior, as well as how the transformation between the first- to second- and second- to third- order neurons impact this expressed behavior. By combining optogenetics, electrophysiology, computational modeling, and behavior, this proposal seeks to further our understanding of how the nervous system integrates sensory information to execute an accompanying motor plan.