Schneck M E, Adams A J, Volbrecht V J, Haegerstrom-Portnoy G
School of Optometry, University of California, Berkeley 94720.
Vision Res. 1990;30(7):973-83. doi: 10.1016/0042-6989(90)90106-u.
Rod saturation on flashed and steady red backgrounds was investigated in normals and three achromats, two of whom were found to have some residual cone function. LWS cones selectively reduce the background level at which rod saturation occurs and elevate rod thresholds at flashed background levels well below saturation. Both of these LWS cone actions are also present in eyes with greatly reduced LWS cone function. In normal eyes LWS cones also elevate rod thresholds on steady backgrounds. We thus conclude that LWS cones influence rods through different mechanisms under transient (flashed) and steady-state background stimulation and that the increase in rod visual sensitivity observed during prolonged presentation of a background is due to a time-dependent reduction of LWS cone influence on rods. Finally, the finding that rod-cone interactions of the same magnitude found in normals can be seen in individuals where the cones' ability to mediate vision is severely reduced suggests the rod saturation paradigm as a sensitive technique for revealing residual LWS cone function.
在正常人和三名色盲患者中研究了在闪烁和稳定红色背景下的视杆细胞饱和情况，其中两名色盲患者被发现仍有一些残余的视锥细胞功能。长波敏感（LWS）视锥细胞选择性地降低视杆细胞发生饱和的背景亮度水平，并在远低于饱和的闪烁背景亮度水平下提高视杆细胞阈值。这两种LWS视锥细胞的作用在LWS视锥细胞功能大幅降低的眼睛中也存在。在正常眼睛中，LWS视锥细胞在稳定背景下也会提高视杆细胞阈值。因此，我们得出结论，LWS视锥细胞在瞬态（闪烁）和稳态背景刺激下通过不同机制影响视杆细胞，并且在长时间呈现背景期间观察到的视杆细胞视觉敏感性增加是由于LWS视锥细胞对视杆细胞的影响随时间而降低。最后，在视锥细胞介导视觉的能力严重降低的个体中也能看到与正常人相同程度的视杆 - 视锥细胞相互作用，这一发现表明视杆细胞饱和范式是揭示残余LWS视锥细胞功能的一种灵敏技术。
