Contributions of retinal ON and OFF pathways to visual information processing in mice

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14850
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 46030:Function of nervous system-related
• Research Institution: Osaka University
• Principal Investigator: Sugita Yuko 大阪大学, 蛋白質研究所, 助教 (30712301)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 神経科学 / 視覚 / 網膜 / 眼球運動 / マウス

Outline of Final Research Achievements

To understand the temporal characteristic of the visual processing underlying optokinetic responses (OKRs) between ON pathway and OFF pathway, we examined transient ocular response elicited by two-frame animations presented with the inter-stimulus interval (ISI). We studied the temporal characteristic of ON pathway by using the mutant mice with dysfunctional ON-bipolar cells that have a functional obstruction of transmission to ON direction selective ganglion cells.In wild-type and mutant mice, OKR decreased with increasing ISI, and finally the direction of visual movement was reversed. In particular, in the case of retinal ON-type bipolar cell-deficient mice, progressive reduction of OKR and direction reversal were observed at shorter ISI than in wild-type mice. These results suggest that the temporal characteristic of ON pathway is slower than those of OFF pathway and indicate different roles of the ON and OFF pathways in the temporal course of OKRs in mice.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

網膜はON・OFF経路の並列情報処理を行うことが動物種を超えた大きな特徴であるが、網膜情報処理の柱となるONとOFF経路の情報処理のメカニズムや並列情報処理の生理学的意義といった重要な問題はいまだ解明されていない。本研究は、申請者の所属研究室が実績を有する遺伝子改変マウス作製技術や申請者が確立したマウス精密OKRの測定解析技術と組み合わせることによって、今まで未解明であった視覚におけるON・OFF経路の機能的意義を明らかにできる重要な研究になると考えている。