Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual system, information is split into two separate pathways, ON and OFF, which encode increments and decrements in light intensity, respectively. The importance of this segregation is borne out in the fact that receptive fields in higher visual centers maintain a separation between ON and OFF regions. In the past decade, the molecular mechanisms underlying the generation of ON signals have been identified, which are unique in their use of a G-protein signaling cascade. In this review, we consider advances in our understanding of G-protein signaling in ON-bipolar cell (BC) dendrites and how insights about signaling have emerged from visual deficits, mostly night blindness. Studies of G-protein signaling in ON-BCs reveal an intricate mechanism that permits the regulation of visual sensitivity over a wide dynamic range.

中文翻译：

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视网膜双极细胞中的转导级联：信号处理和疾病。

我们强大的视觉体验是基于信息从我们的感光细胞、视杆细胞和视锥细胞到更高的大脑中枢的可靠传输。在视觉系统的第一个突触处，信息被分成两个独立的通路，ON 和 OFF，它们分别编码光强度的增量和减量。这种隔离的重要性体现在更高视觉中心的感受野在 ON 和 OFF 区域之间保持分离。在过去的十年中，已经确定了产生 ON 信号的分子机制，这些机制在使用 G 蛋白信号级联方面是独一无二的。在这篇综述中，我们考虑了对双极细胞 (BC) 树突中 G 蛋白信号传导的理解进展，以及对信号传导的洞察力如何从视觉缺陷中产生，主要是夜盲症。对 ON-BC 中 G 蛋白信号传导的研究揭示了一种复杂的机制，该机制允许在宽动态范围内调节视觉灵敏度。