수업
협동과정 뇌과학전공 초청세미나 5.18 (연사: 김안모 성균관대학교 교수)
2023-05-15
- 제목 : Feedforward and feedback signaling in Drosophila vision
- 연사 : 김안모 교수님 (성균관대학교 융합전자공학부)
- 초정자 : 강봉균 교수님 (서울대학교 생명과학부)
- 일시 : 2023년 5월 18일 (목) 오전 11시
- 장소: 서울대학교 관악캠퍼스 28동 101호
- Abstract : When reading a book, our eyes move briskly from one word to another, resetting the retinal image a few times a second; yet, we perceive the book's page as stable. Our brains accomplish this remarkable feat by filtering out visual input during fast eye movements and somehow stitching together images collected at different fixation points. As in this example, across animals and modalities, sensory processing does not merely involve a feedforward transformation of sensory stimuli but includes an interplay of feedforward and feedback (or top-down) signaling. To understand the detailed neural mechanisms underlying such processes, we performed whole-cell patch clamping, calcium imaging, and massive behavioral genetics experiments in tethered, flying Drosophila. We studied feedforward visual circuits involved in various visual behaviors, such as optomotor stabilization, bar fixation, spot avoidance, and loom avoidance. Then, we tested how these multiple visual pathways, acting simultaneously on the wing motor system, are orchestrated by feedback signaling, called an efference copy. Based on these experimental results, we built an integrative model that closely predicts how a flying fruit fly steers its wings in response to different visual patterns, as an outcome of feedforward and feedback signaling. The experimental and modeling studies together suggest that feedback signaling is necessary for the animal to respond selectively and rapidly to visual objects in a cluttered visual environment.