Suppression of distributed sensory representations by self-motion cues in Drosophila

/ABSTRACT To ensure accurate perception of the world, nervous systems must distinguish between sensory inputs caused by external stimuli and those generated by the body’s own movements. During rapid eye movements, or saccades, the brain suppresses sensory signals from self-generated motion through a process known as saccadic suppression. However, little is known about how this suppression affects the feature encoding capabilities of specific cell types within a visual network and the impact on broader visual processing. This project aims to elucidate the neural mechanisms of saccadic suppression using the Drosophila melanogaster model, which offers unparalleled genetic access and a tractable nervous system with a fully mapped connectome. The research will focus on the Lobula Columnar (LC) cell network, which encodes specific visual features and is known to exhibit suppression during body saccades. The project has three specific aims: (1) to characterize the neural inputs contributing to saccadic suppression in LC neurons through electrophysiological recordings and connectomic analysis, (2) to evaluate how saccadic suppression affects feature encoding across the LC network using population-level two-photon calcium imaging and advanced analytical techniques, and (3) to develop a computational model predicting how suppression impacts distinct LC subpopulations and their contributions to visual perception. This research will provide fundamental insights into how self-generated motion is processed and suppressed across visual systems. As part of the fellowship, I will receive training in electrophysiology, calcium imaging, and computational modeling under the mentorship of Drs. Gwyneth Card, Rudy Behnia, and Larry Abbott at Columbia University’s Zuckerman Institute. This world-class environment will provide me with the necessary skills and resources to achieve my long-term goal of establishing an independent research program focused on sensorimotor integration and neural circuit function. Project Number: 1F32NS144013-01 | Fiscal Year: 2025 | NIH Institute/Center: National Institute of Neurological Disorders and Stroke (NINDS) | Principal Investigator: Sachira Denagamage | Institution: COLUMBIA UNIVERSITY HEALTH SCIENCES, NEW YORK, NY | Award Amount: $75,520 | Activity Code: F32 | Study Section: NST-4 Study Section [NST-4] View on NIH RePORTER: https://reporter.nih.gov/project-details/11212315