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Animal behavior reflects the interplay of two types of responses: those that arise innately, from neural circuits pre-programmed into the genome, and those acquired by learning from past experience. Using the fruit fly Drosophila melanogaster, Ruta works to define the neural-circuit mechanisms that generate innate and learned behaviors.

Animal behavior arises from an interplay between instinct and learning. Certain behaviors are innate and invariant across members of a species, suggesting they are genetically programmed into the nervous system. However, behavior must also be highly flexible to allow individuals to adapt to their unique and changing experience of the world. A major focus of the Ruta lab is to delineate the distinct neural circuits and computations that underlie innate and learned behaviors, and to reveal how these circuits can be modified through evolution or individual experience to generate novel behavioral adaptations. To accomplish this, the group uses a multidisciplinary toolkit—including optical tracing techniques, electrophysiology, functional imaging, and behavior—to study the concise chemosensory circuits of the fly, with the goal of revealing how they mediate fixed and flexible behaviors at the level of synapses, cells, and circuit motifs.

In recent work, the Ruta lab has examined how the nervous system is wired to flexibly encode and assign meaning to the complex and vast chemical world. By examining the functional architecture of the Drosophila mushroom body, an associative brain center in the fly that is essential for olfactory learning and memory, they shed light on the synaptic and circuit mechanisms that mediate flexible odor processing, demonstrating how neuromodulation can act to rapidly reconfigure circuit properties and allow the same odor to drive alternative behavioral responses. In parallel, the Ruta lab has used Drosophila courtship as a paradigm to explore how innate behaviors emerge from genetically specified neural circuits and are modified through evolution to generate species-specific variations in mating behavior.

All olfactory behaviors in the fly, whether innate or learned, are initiated through the same molecular recognition events: the binding of volatile chemical cues to odorant receptors expressed in peripheral sensory neurons. Odorant receptors in insects, unlike in mammals, are thought to function as heteromeric odor-gated ion channels. To begin to reveal how the binding of odorant ligands is coupled to ion flux in this large and diverse family of membrane proteins, the Ruta lab is performing biochemical, electrophysiological, and structural studies on insect odorant receptors. The aim is to provide insight into the molecular basis for odorant signaling in insects and to lay the foundation for the development of novel strategies to prevent the transmission of insect-borne diseases.

Ruta is a faculty member in the David Rockefeller Graduate Program, the Tri-Institutional M.D.-Ph.D. Program, and the Tri-Institutional Ph.D. Program in Chemical Biology.