Opponent melanopsin and S-cone signals in the human pupillary light response
Opponent melanopsin and S-cone signals in the human pupillary light response
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DOI：
10.1073/pnas.1400942111
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发表时间：
2014-10-28
影响因子：
11.1
通讯作者：
Aguirre, Geoffrey K.
中科院分区：
文献类型：
--
作者：
Spitschan, Manuel;Jain, Sandeep;Aguirre, Geoffrey K.
在人类中，视锥光感受器（L、M和S）和含有黑视素-黑视素的固有光敏视网膜神经节细胞（ipRGC）在日间光强度下是活跃的。来自视锥细胞的信号以相加和相反的方式结合在一起，以产生对整体光线和颜色的感知。在控制瞳孔对光的反应方面，似乎也有类似的机制在起作用。然而，未表征的是黑视蛋白和S锥的相对贡献，其重叠，短波长光谱敏感性。我们测量了在明视条件下，在一定范围的时间频率下，人类瞳孔对视锥细胞和黑视蛋白的单独刺激的反应。研究发现，S-锥和黑视蛋白光感受器通道含有内在光敏视网膜神经节细胞（ipRGC），在白天光照强度下是活跃的。来自视锥细胞的信号以相加和相反的方式结合在一起，以产生对整体光线和颜色的感知。在控制瞳孔对光的反应方面，似乎也有类似的机制在起作用。然而，未表征的是黑视蛋白和S锥的相对贡献，其重叠，短波长光谱敏感性。我们测量了在明视条件下，在一定范围的时间频率下，人类瞳孔对视锥细胞和黑视蛋白的单独刺激的反应。发现S-视锥和黑视蛋白光感受器通道是低通的，与瞳孔对L-和M-视锥信号的带通响应相反。诱发反应的相位关系的检查显示，黑视蛋白信号与来自L和M视锥的信号相加，但与来自S视锥的控制瞳孔的信号相反。S锥的对立显示在一个看似矛盾的瞳孔扩大，以更大的S锥光子捕获。这一令人惊讶的结果可以通过动物研究中发现的ipRGC的神经生理学特性来解释。
In the human, cone photoreceptors (L, M, and S) and the melanopsin-melanopsincontaining, intrinsically photosensitive retinal ganglion cells (ipRGCs) are active at daytime light intensities. Signals from cones are combined both additively and in opposition to create the perception of overall light and color. Similar mechanisms seem to be at work in the control of the pupil's response to light. Uncharacterized however, is the relative contribution of melanopsin and S cones, with their overlapping, short-wavelength spectral sensitivities. We measured the response of the human pupil to the separate stimulation of the cones and melanopsin at a range of temporal frequencies under photopic conditions. The S-cone and melanopsin photoreceptor channels were found tcontaining, intrinsically photosensitive retinal ganglion cells (ipRGCs) are active at daytime light intensities. Signals from cones are combined both additively and in opposition to create the perception of overall light and color. Similar mechanisms seem to be at work in the control of the pupil's response to light. Uncharacterized however, is the relative contribution of melanopsin and S cones, with their overlapping, short-wavelength spectral sensitivities. We measured the response of the human pupil to the separate stimulation of the cones and melanopsin at a range of temporal frequencies under photopic conditions. The S-cone and melanopsin photoreceptor channels were found to be low-pass, in contrast to a band-pass response of the pupil to L-and M-cone signals. An examination of the phase relationships of the evoked responses revealed that melanopsin signals add with signals from L and M cones but are opposed by signals from S cones in control of the pupil. The opposition of the S cones is revealed in a seemingly paradoxical dilation of the pupil to greater S-cone photon capture. This surprising result is explained by the neurophysiological properties of ipRGCs found in animal studies.