Jin Nange, Tian Lian-Ming, Fahrenfort Iris, Zhang Zhijing, Postma Friso, Paul David L, Massey Stephen C, Ribelayga Christophe P
Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA.
Department of Neurobiology, Medical School, Harvard University, Boston, MA, USA.
Sci Adv. 2022 Apr;8(13):eabm4491. doi: 10.1126/sciadv.abm4491. Epub 2022 Apr 1.
In the retina, signals originating from rod and cone photoreceptors can reach retinal ganglion cells (RGCs)-the output neurons-through different pathways. However, little is known about the exact sensitivities and operating ranges of these pathways. Previously, we created rod- or cone-specific knockout (KO) mouse lines. Both lines are deficient in rod/cone electrical coupling and therefore provide a way to selectively remove the secondary rod pathway. We measured the threshold of the primary rod pathway in RGCs of wild-type mice. Under pharmacological blockade of the primary rod pathway, the threshold was elevated. This secondary component was removed in the KOs to unmask the threshold of the third rod pathway, still below cone threshold. In turn, the cone threshold was estimated by several independent methods. Our work defines the functionality of the secondary rod pathway and describes an additive contribution of the different pathways to the retinal output.
在视网膜中，源自视杆和视锥光感受器的信号可通过不同途径到达视网膜神经节细胞（RGCs）——输出神经元。然而，对于这些途径的确切敏感性和工作范围知之甚少。此前，我们创建了视杆或视锥特异性敲除（KO）小鼠品系。这两个品系均缺乏视杆/视锥电耦合，因此提供了一种选择性去除次级视杆途径的方法。我们测量了野生型小鼠RGCs中初级视杆途径的阈值。在初级视杆途径的药理学阻断下，阈值升高。在敲除小鼠中去除了这个次级成分，以揭示第三条视杆途径的阈值，该阈值仍低于视锥阈值。反过来，通过几种独立方法估计了视锥阈值。我们的工作定义了次级视杆途径的功能，并描述了不同途径对视网膜输出的累加贡献。
