BME PhD Preliminary Exam Announcement for Elizabeth Frazier (M. Dadarlat, Chair) Everyone is invited to attend the public presentation beginning at 10:00 AM. Title: Using coherent motion perception to probe effects of traumatic brain injury on cortical physiology Date: March 31, 2025 Time: 10:00 AM Location: MRGN 129 or Zoom: https://purdue-edu.zoom.us/j/91715896410<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpurdue-edu.zoom.us%2Fj%2F91715896410&data=05%7C02%7Cbmeroundtable-list%40ecn.purdue.edu%7C99e2653bf2614bc30a3908dd66604d9f%7C4130bd397c53419cb1e58758d6d63f21%7C0%7C0%7C638779285995475597%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=y1F7ylimvZK1iEhEPXhdvpv43D8clZQRnheiqdQzSWo%3D&reserved=0> Committee Members: Dr. Maria Dadarlat (chair) Dr. Anne Sereno Dr. Ed Bartlett Dr. Alex Chubykin Abstract: Traumatic brain injuries (TBIs) affect over 55 million individuals annually, with approximately 75% classified as mild (mTBI). mTBIs are characterized by an absence of overt structural brain damage detectable with conventional clinical imaging technologies. Despite this, up to 30% of mTBI cases lead to persistent visual dysfunction, including deficits in visual acuity, binocular coordination, spatial perception, and motion sensitivity. However, the neural mechanisms underlying these persistent visual deficits remain poorly characterized. Prior studies have reported elevated motion coherence detection thresholds following mTBI, suggesting a disruption in the cortical processing of global motion that correlates with prolonged recovery of normal visual function. I hypothesize that by correlating changes in visual perception with changes in neural dynamics after mTBI, we can use performance on a simple behavioral task to estimate less accessible measures of pathophysiological damage and injury prognosis. To test this hypothesis, I will first train mice to perform a perceptual decision-making task using a coherent motion stimulus while simultaneously recording population-level neural activity from the visual cortex with large field-of-view two-photon calcium imaging. This study will characterize the encoding of coherent motion information for reliable perceptual decision-making under normal sensory function (Aim 1). I will then administer a mTBI to perturb these neural dynamics and analyze how the resulting changes in neural activity map to deficits in coherent motion perception (Aim 2). Ultimately, this work will provide mechanistic insights into the cortical substrates of visual perceptual deficits following mTBI, informing the development of a behavioral biomarker to enhance diagnostic sensitivity and guide targeted rehabilitation strategies for individuals with persistent mTBI-related visual dysfunctions. -- Bmeroundtable-list mailing list Bmeroundtable-list@ecn.purdue.edu https://engineering.purdue.edu/ECN/mailman/listinfo/bmeroundtable-list