Angle-resolved polarization signal imaging of early receptor potential

项目描述（由申请人提供）：本项目旨在探讨完整视网膜早期受体电位（ERP）极化信号成像的可行性。先前的研究表明，在可见光激活的孤立光感受器外段中，由于erp相关的双折射变化，存在偏振信号响应。然而，由于视网膜结构复杂，在完整视网膜中成像erp相关的双折射变化在技术上具有挑战性。原则上，双折射和散射变化都能在视网膜中产生瞬态偏振信号。为了实现erp相关双折射变化的鲁棒成像，减小光散射对测量的影响是很重要的。在本项目中，我们建议开发一种高速光场光学相干层析成像（OCT）成像仪，并验证其用于双折射和散射相关偏振信号的光学分离。提出的光场OCT成像仪将提供角度分辨偏振信号成像的能力。原则上，当使用斜光照明时，合成角滤光片将允许光散射和双折射相关的偏振信号在光激活的视网膜中进行光学分离。分离的龙虾神经轴突将被用作拟议成像仪功能测试的过渡准备。将使用青蛙视网膜切片和完整视网膜来证明erp相关双折射响应偏振信号成像的可行性。虽然我们的最终目标是使用所提出的技术来诊断视网膜疾病，但这个R21项目将专注于光场成像系统的技术开发和功能验证。该项目的成功实施将为开发客观、高分辨率的光感受器功能评估仪器奠定坚实的基础。

DESCRIPTION (provided by applicant): The objective of this project is to explore the feasibility of polarization signal imaging of early receptor potential (ERP) in intact retinas. Previous investigations have demonstrated the existence of polarization signal response due to ERP-associated birefringence change in isolated photoreceptor outer segments activated by visible light. However, imaging of the ERP-associated birefringence change in intact retina is technically challenging because of complex structure of the retina. In principle, both birefringence and scattering changes can produce transient polarization signals in the retina. In order to achieve robust imaging of ERP-associated birefringence change, it is important to reduce the effect of light scattering on the measurement. In this project, we propose to develop a high speed light-field optical coherence tomography (OCT) imager, and to validate it for optical separation of birefringence- and scattering-associated polarization signals. The proposed light-field OCT imager will provide capability of angle-resolved polarization signal imaging. In principle, when an oblique light illumination is used, synthetic angular filters will allow optical separation of light scattering- and birefringence-associated polarization signals in the light activated retina. Isolated lobster nerve axons will be employed as a transition preparation for functional test of the proposed imager. Frog retinal slices and intact retinas will be used to demonstrate the feasibility of polarization signal imaging of ERP-associated birefringence response. Although our ultimate goal is to use the proposed technology to diagnose of retinal diseases, this R21 project will focus on technical development and functional validation of the light-field imaging system. Successful implementation of this project will build a solid foundation for the development of objective, high resolution instruments for photoreceptor function evaluation. PUBLIC HEALTH RELEVANCE: The proposed light-field imager will provide capability of high resolution imaging of stimulus-evoked early receptor potential. High resolution evaluation of photoreceptor response can lead to better study and diagnosis of the retina.