Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA; Neuroscience Honors Research Program, William Marsh Rice University, Houston, TX, USA.
Department of Neuroscience, Wexner Medical Center, College of Medicine, The Ohio State University, Columbus, OH, USA.
Prog Retin Eye Res. 2023 May;94:101119. doi: 10.1016/j.preteyeres.2022.101119. Epub 2022 Dec 8.
Circadian (24-h) clocks are cell-autonomous biological oscillators that orchestrate many aspects of our physiology on a daily basis. Numerous circadian rhythms in mammalian and non-mammalian retinas have been observed and the presence of an endogenous circadian clock has been demonstrated. However, how the clock and associated rhythms assemble into pathways that support and control retina function remains largely unknown. Our goal here is to review the current status of our knowledge and evaluate recent advances. We describe many previously-observed retinal rhythms, including circadian rhythms of morphology, biochemistry, physiology, and gene expression. We evaluate evidence concerning the location and molecular machinery of the retinal circadian clock, as well as consider findings that suggest the presence of multiple clocks. Our primary focus though is to describe in depth circadian rhythms in the light responses of retinal neurons with an emphasis on clock control of rod and cone pathways. We examine evidence that specific biochemical mechanisms produce these daily light response changes. We also discuss evidence for the presence of multiple circadian retinal pathways involving rhythms in neurotransmitter activity, transmitter receptors, metabolism, and pH. We focus on distinct actions of two dopamine receptor systems in the outer retina, a dopamine D receptor system that mediates circadian control of rod/cone gap junction coupling and a dopamine D receptor system that mediates non-circadian, light/dark adaptive regulation of gap junction coupling between horizontal cells. Finally, we evaluate the role of circadian rhythmicity in retinal degeneration and suggest future directions for the field of retinal circadian biology.
昼夜节律（24 小时）时钟是细胞自主的生物振荡器，它每天协调我们生理的许多方面。已经观察到哺乳动物和非哺乳动物视网膜中存在许多昼夜节律，并且已经证明存在内源性昼夜节律时钟。然而，时钟和相关节律如何组装成支持和控制视网膜功能的途径在很大程度上仍然未知。我们的目标是综述我们目前的知识状况并评估最新进展。我们描述了许多以前观察到的视网膜节律，包括形态学、生物化学、生理学和基因表达的昼夜节律。我们评估了有关视网膜昼夜节律时钟的位置和分子机制的证据，以及表明存在多个时钟的发现。然而，我们的主要重点是详细描述视网膜神经元光反应的昼夜节律，重点是时钟对杆和锥途径的控制。我们研究了特定生化机制产生这些每日光反应变化的证据。我们还讨论了存在涉及神经递质活性、递质受体、代谢和 pH 节律的多个昼夜视网膜途径的证据。我们关注外视网膜中两个多巴胺受体系统的不同作用，一种是介导昼夜节律控制杆/锥间隙连接偶联的多巴胺 D 受体系统，另一种是介导水平细胞之间间隙连接偶联的非昼夜节律、光/暗适应性调节的多巴胺 D 受体系统。最后，我们评估了昼夜节律性在视网膜变性中的作用，并为视网膜昼夜节律生物学领域提出了未来的方向。
