Imaging outer segment renewal in living human cone photoreceptors.
Imaging outer segment renewal in living human cone photoreceptors.
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DOI：
10.1364/oe.18.005257
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发表时间：
2010-03-01
期刊：
影响因子：
3.8
通讯作者：
Miller DT
中科院分区：
文献类型：
--
作者：
Jonnal RS;Besecker JR;Derby JC;Kocaoglu OP;Cense B;Gao W;Wang Q;Miller DT
在脊椎动物的眼睛中，当光感受器的外部部分吸收光子并产生目的地为大脑的神经信号时，视觉就开始了。这一光转导过程的极端光学和代谢需求需要不断更新外层部分。使用放射自显影技术在死后视杆细胞中研究外节更新由来已久，但尚未在活体感光细胞或视锥细胞中直接观察到。使用自适应光学，它允许锥体的分辨率，和时间相干照明，它转换外部部分为“生物干涉仪”，我们观察到三个受试者的锥体更新，表现为锥体外部部分的延长，速率从93到113 nm/小时(2.2到2.7μm/天)。在一个受试者中，我们观察到续订发生在24小时内，续约率在一天中发生了微小但显著的变化。我们确定这种新的方法对139 nm的外节长度的变化很敏感，比超高分辨率光学相干层析成像的轴向分辨率高20多倍，超高分辨率光学相干层析成像是现存最好的活体视网膜深度成像方法。
In vertebrate eyes, vision begins when the photoreceptor's outer segment absorbs photons and generates a neural signal destined for the brain. The extreme optical and metabolic demands of this process of phototransduction necessitate continual renewal of the outer segment. Outer segment renewal has been long studied in post-mortem rods using autoradiography, but has been observed neither in living photoreceptors nor directly in cones. Using adaptive optics, which permits the resolution of cones, and temporally coherent illumination, which transforms the outer segment into a “biological interferometer,” we observed cone renewal in three subjects, manifesting as elongation of the cone outer segment, with rates ranging from 93 to 113 nm/hour (2.2 to 2.7 μm/day). In one subject we observed renewal occurring over 24 hours, with small but significant changes in renewal rate over the day. We determined that this novel method is sensitive to changes in outer segment length of 139 nm, more than 20 times better than the axial resolution of ultra-high resolution optical coherence tomography, the best existing method for depth imaging of the living retina.