Department of Information Science and Biomedical Engineering, Kagoshima University, Kagoshima, Japan.
Ophthalmic Physiol Opt. 2011 Sep;31(5):469-79. doi: 10.1111/j.1475-1313.2011.00846.x. Epub 2011 Jun 6.
A recent study has shown that retinal ganglion cells containing the photopigment melanopsin, which are intrinsically photosensitive in primates, project to the pupillary control centre in the pretectum. The aim of this study was to investigate how melanopsin retinal ganglion cells (mRGCs) contribute to the pupillary pathway.
We designed and built a novel multi-primary stimulation system to control stimulation of the three cone types and mRGCs independently in the human eye. We measured the latency and amplitude of transient pupillary responses to three types of test stimuli modulating excitations of mRGCs and cones (mRGC, luminance and the light flux stimuli).
It was found that the transient pupillary response to mRGC stimuli has a longer latency than that to luminance and the light flux stimuli when an onset of sinusoidal stimulus was used.
The results indicate that we successfully demonstrated the pupillary response to mRGCs under conditions where mRGCs are isolated in humans. Furthermore, the data confirm that the delayed response disappeared when the stimulus is presented as a square-wave pulse and not weighted by a sinusoid. The similarity of time courses for the earlier phase of pupillary responses to all stimuli suggested that these transient pupillary responses were driven by a single mechanism, which is perhaps associated with cone-mediated signals.
最近的一项研究表明，在灵长类动物中，含有光色素黑视素的视网膜神经节细胞具有内在感光性，它们投射到顶盖前瞳孔控制中心。本研究旨在探讨黑视素视网膜神经节细胞（mRGCs）如何参与瞳孔途径。
我们设计并构建了一种新型多原色刺激系统，可独立控制人眼中三种视锥细胞和 mRGCs 的刺激。我们测量了瞬态瞳孔对三种调制 mRGCs 和视锥细胞（mRGC、亮度和光通量刺激）激发的测试刺激的潜伏期和振幅。
发现当使用正弦波刺激起始时，mRGC 刺激的瞬态瞳孔反应的潜伏期长于亮度和光通量刺激。
结果表明，我们成功地在人类中证明了在分离 mRGC 的情况下对 mRGC 的瞳孔反应。此外，当刺激呈方波脉冲而不是正弦波加权时，延迟响应消失。所有刺激的瞳孔早期反应的时间过程相似，表明这些瞬态瞳孔反应是由单一机制驱动的，该机制可能与视锥细胞介导的信号有关。
