RELATED STORIES: Rita Allen Foundation Scholar Harnesses Sound Waves to Activate Brain Cells, Rita Allen Foundation Scholars Reveal Biological Forces That Underlie Responses to Change
Sreekanth Chalasani obtained a B.S. degree and an advanced diploma in computer science from Osmania University in Hyderabad, India. He then did research at the National Center for Biological Sciences in Bangalore, India, before coming to the U.S. in 1997. Chalasani obtained a Ph.D. from the University of Pennsylvania, where he worked with Jonathan Raper, and did postdoctoral research in Cornelia Bargmann’s laboratory at the University of California, San Francisco, and The Rockefeller University. He started his laboratory at the Salk Institute for Biological Studies in 2010. In addition to the Rita Allen Foundation award, Chalasani has received awards including a Blavatnik Award for Young Scientists, a Basil O’Connor Starter Award from the March of Dimes, and a W.M. Keck Foundation Award.
Chalasani’s research addresses how the brain responds to changes in its surrounding environment. Neural circuits within the brain extract relevant information from the environment and regulate behaviors on timescales ranging from seconds to hours. A complete understanding of this process requires an ability to identify, record and manipulate all the participating neurons. It is difficult to obtain this level of access in a complex vertebrate brain. Chalasani’s group is using the nematode C. elegans, with its small, well-defined nervous systems, to decode the cellular and molecular mechanisms transforming environmental changes into behaviors. They have shown that C. elegans can evaluate the size of a patch of bacteria (its food) and uses that information to modify a behavior that lasts many minutes. In particular, they have identified sensory neurons that encode the size of a food patch by detecting large, but not small, changes in food. Moreover, they show that information about patch size is stored in the level of dopamine in the circuit, which acts to modify downstream sensory and interneurons. Also, they find that the rate of acquiring information is controlled by the amount of CREB protein in key interneurons in the circuit.