Department of Neurobiology, Northwestern University, Evanston, United States.
Department of Biology, Johns Hopkins University, Baltimore, United States.
Elife. 2018 Nov 7;7:e39866. doi: 10.7554/eLife.39866.
Retinal dopamine is a critical modulator of high acuity, light-adapted vision and photoreceptor coupling in the retina. Dopaminergic amacrine cells (DACs) serve as the sole source of retinal dopamine, and dopamine release in the retina follows a circadian rhythm and is modulated by light exposure. However, the retinal circuits through which light influences the development and function of DACs are still unknown. Intrinsically photosensitive retinal ganglion cells (ipRGCs) have emerged as a prime target for influencing retinal dopamine levels because they costratify with DACs in the inner plexiform layer and signal to them in a retrograde manner. Surprisingly, using genetic mouse models lacking specific phototransduction pathways, we find that while light influences the total number of DACs and retinal dopamine levels, this effect does not require ipRGCs. Instead, we find that the rod pathway is a critical modulator of both DAC number and retinal dopamine levels.
视网膜多巴胺是影响高分辨率、光适应视觉和光感受器偶联的关键调节剂。多巴胺能无长突细胞（DACs）是视网膜多巴胺的唯一来源，视网膜中的多巴胺释放遵循昼夜节律，并受光暴露的调节。然而，目前尚不清楚光通过何种视网膜回路影响 DACs 的发育和功能。光感受器神经节细胞（ipRGCs）已成为影响视网膜多巴胺水平的主要靶点，因为它们与 DACs 在内丛状层共定位，并以逆行方式向其传递信号。令人惊讶的是，使用缺乏特定光转导途径的基因敲除小鼠模型，我们发现虽然光会影响 DACs 的总数和视网膜多巴胺水平，但这一效应并不需要 ipRGCs。相反，我们发现视杆通路是调节 DAC 数量和视网膜多巴胺水平的关键因素。
