MIT Colloquium on Brain and Cognition with Vanessa Ruta

Theme and variations: circuit mechanisms of behavioral evolution

Animals exhibit an astonishing variation in their behavior, yet little is known about the neural mechanisms that generate this diversity. To gain insight into mechanisms of behavioral evolution, we have begun to translate neurogenetic tools from D. melanogaster to closely related Drosophila species, allowing us to directly compare homologous neural circuits and pinpoint sites of adaptive change. In recent work, we compared pheromone-processing pathways in D. melanogaster and D. simulans to define how these sister species endow the same pheromone, 7,11-hepatcosadiene, with the opposite behavioral valence to underlie mate discrimination. Our results reveal that species-specific pheromone responses can emerge from conservation of the sensory periphery and diversification of central circuitry, and demonstrate how variation at discrete nodes in neural circuits can contribute to behavioral evolution. We are now taking advantage of the rapid evolution of female pheromones in the Drosophila genus to examine how parallel changes in mating behaviors have been independently implemented in different species, shedding light on the types of changes that are possible and preferable within brain circuits.

Vanessa Ruta received a PhD from Rockefeller University where she worked with Rod MacKinnon to define the structural basis for voltage-sensing in voltage-dependent ion channels. During her post-doctoral training, she transitioned from studying structure-function relationships at the molecular level to examining the functional architecture of neural circuits in Drosophila in Richard Axel’s lab at Columbia University. Ruta joined Rockefeller University at the end of 2011, where she currently heads the Laboratory of Neurophysiology and Behavior. The central focus of the Ruta lab is to explore how neural circuits can be flexibly modified through individual experience or over evolution to generate adaptive variations in behavior. By applying a broad multidisciplinary toolkit to study the concise chemosensory circuits of the fly, Ruta’s goal is to reveal how these pathways mediate fixed and flexible behaviors at the level of synaptic, cellular and circuit motifs. Ruta is the recipient of a number of fellowships and awards including a MacArthur Fellowship, a McKnight Scholar Award, a Pew Biomedical Scholar Award, an NIH New Innovator Award and a Sloan Foundation Research Fellowship and was named a Robertson Neuroscience Investigator by the New York Stem Cell Foundation.

Host

Steven Flavell

Organizer

Brittany Greenough