[대학원 생명과학과 세미나 안내]
연사 : 이광 교수(대구경북과학기술원, 뇌과학과)
연제 : Neural circuit dynamics in reward-conditioned movement
일시 : 2022년 11월 11일 (금) 오후 4시 30분
장소 : 하나과학관 A동 109호
초청교수 : 백자현 교수
Abstract
The neural dynamics research addresses how the brain activity and circuitry lead to complex behaviors involving learning, prediction, decision making and memory. The striatum and midbrain are central to reinforcing learning and to generating movement. Cortical and thalamic projections provide excitatory drive to the striatum, but little is known about how these inputs, either individually or collectively, regulate striatal dynamics during behavior. We investigated how behaviorally evoked neural dynamics in the lateral striatum are shaped by multiple inputs corresponding to the cortex and thalamus. By comparing the effect of suppressing one, two, or three projections on firing rate, we found that MSNs appear to combine cortical and thalamic input signals through multiplication. In support of a multiplicative effect, the gain of the neuronal response varied with the number of simultaneously suppressed inputs. These results reveal a simple yet computationally powerful signal processing function of the striatum. Midbrain dopamine (DA) neurons encode both reward and movement-related events, and are implicated in disorders of reward processing as well as movement. Dynamic activity of DA neurons in midbrain gives rise to a significantly stronger contribution in reinforcing rather than generating conditioned movements. Together, the results indicate a temporally restricted rule of DA neurons primarily related to reinforcing stimulus-reward associations, and suggest that directly generating movements is a comparatively less important function.