From Sensation to Action
Thursday, January 17, 2019
12:00 PM-1:30 PM
BIOMED Special Seminar
From Sensation to Action
Vikas Bhandawat, PhD
Assistant Professor of Biology
Assistant Professor in Neurobiology
A simple task, like walking to one's favorite coffee shop, involves computation across several timescales. On a short time scale (< 1s), one has to move one's legs on an uneven surface and maintain balance. On a medium time-scale (~ few seconds) one has to walk relatively straight on a sidewalk. On a longer time-scale (~ minutes), one has to follow the street signs or use one's memory to navigate. On an even longer time-scale are decisions such as whether or not to drink coffee.
Dr. Bhandawat's talk will focus on the behavioral algorithms at each of these different time scales, identifying the neural circuits that execute them, and understanding the neural computations underlying behavior at these different timescales. He will pursue this question in the context of the tiny fruit fly's olfactory system.
Vikas Bhandawat, PhD, earned his doctorate from Johns Hopkins University in 2004. His main research has revolved around a major goal in neuroscience to understand how neural circuits represent sensory information or guide behavior. Because of the complexity of our nervous system it is often difficult to pinpoint the neurons that participate in a given task. Our overall aim is to map out “complete circuits” underlying simple and complex behaviors and understand neural computations with a knowledge of this complete circuit in hand.
Dr. Bhandawat and his team's approach has been to focus on the relatively simple brain of Drosophila to attack this problem. The fly’s brain can perform a surprisingly diverse array of behaviors with relatively few neurons (~100,000). In particular, the olfactory circuit of Drosophila is uniquely appropriate for studying this question because its anatomical organization makes it possible to quantify the pool of neurons activated by a given stimulus. This anatomical simplification occurs because for each odorant receptor gene (there are ~50 in flies), there is an identifiable first-order neuron and an identifiable second-order neuron. Dr. Bhandawat and his team have a nearly complete picture of odor representation at the level of olfactory receptor neurons (ORNs).
Basic principles underlying the transformation of odor responses from ORNs-to-PNs are also understood. Because of this groundwork, odors (stimuli) can readily be mapped onto patterns of ORNs and PNs. Techniques for doing this work include using single-cell recordings from neurons in the fly brain to understand neural computations. We have also developed behavioral paradigms to make quantitative assessment of flies’ behavioral output. He and his team complement these relatively new techniques with molecular genetics in the fly.