Graduate Program in Neuroscience, University of Washington, Seattle, WA, 98109, USA.
School of Optometry and Vision Science Graduate Group, University of California, Berkeley, CA, 94720, USA.
Sci Rep. 2018 Jun 4;8(1):8561. doi: 10.1038/s41598-018-26754-1.
Color vision requires the activity of cone photoreceptors to be compared in post-receptoral circuitry. Decades of psychophysical measurements have quantified the nature of these comparative interactions on a coarse scale. How such findings generalize to a cellular scale remains unclear. To answer that question, we quantified the influence of surrounding light on the appearance of spots targeted to individual cones. The eye's aberrations were corrected with adaptive optics and retinal position was precisely tracked in real-time to compensate for natural movement. Subjects reported the color appearance of each spot. A majority of L-and M-cones consistently gave rise to the sensation of white, while a smaller group repeatedly elicited hue sensations. When blue sensations were reported they were more likely mediated by M- than L-cones. Blue sensations were elicited from M-cones against a short-wavelength light that preferentially elevated the quantal catch in surrounding S-cones, while stimulation of the same cones against a white background elicited green sensations. In one of two subjects, proximity to S-cones increased the probability of blue reports when M-cones were probed. We propose that M-cone increments excited both green and blue opponent pathways, but the relative activity of neighboring cones favored one pathway over the other.
颜色视觉需要在受体后电路中比较锥光感受器的活动。几十年来，心理物理学测量已经在粗糙的尺度上量化了这些比较相互作用的性质。这些发现如何推广到细胞尺度尚不清楚。为了回答这个问题，我们量化了周围光线对靶向单个锥体的斑点外观的影响。通过自适应光学校正眼睛的像差，并实时精确跟踪视网膜位置以补偿自然运动。受试者报告了每个斑点的颜色外观。大多数 L 和 M 锥体一致产生白色的感觉，而一小部分锥体则反复产生色调感觉。当报告蓝色感觉时，它们更可能由 M 锥体介导，而不是 L 锥体。当报告蓝色感觉时，M 锥体受到优先升高周围 S 锥体量子捕获的短波光的刺激，而在白色背景下刺激相同的锥体则会产生绿色感觉。在两名受试者中的一名中，当探测 M 锥体时，S 锥体的接近度增加了蓝色报告的概率。我们提出 M 锥体增量同时激发了绿色和蓝色对立途径，但相邻锥体的相对活性使一个途径优先于另一个途径。
