Somaiya Rachana Deven, Po Matthew A, Feller Marla B, Shekhar Karthik
Department of Neuroscience & Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA.
J Neurosci. 2025 Jul 22. doi: 10.1523/JNEUROSCI.0165-25.2025.
In the early stages of development, correlated activity known as retinal waves causes periodic depolarizations of retinal ganglion cells (RGCs). The β2KO mouse, which lacks the β2 subunit of the nicotinic acetylcholine receptor, serves as a model for understanding the role of the cholinergic waves. β2KO mice have disruptions in several developmental processes of the visual system, including reduced retinotopic and eye-specific refinement of RGC axonal projections to their primary brain targets and an impact on the retinal circuits underlying direction selectivity. However, the effects of this mutation on gene expression in individual functional RGC types remain unclear. Here, we performed single-cell RNA sequencing on RGCs isolated at the end of the first postnatal week from wild-type and β2KO mice of either sex. We found that in β2KO, the programs governing RGC differentiation were not impacted and the magnitude of transcriptional changes was modest compared to those observed during two days of normal postnatal maturation. This contrasts with the substantial transcriptomic changes seen in downstream visual system areas under wave disruption in recent studies. Overall, we identified ∼238 genes whose expression was altered in a type-specific manner. We confirmed this result via hybridization and whole-cell recording by focusing on one of the downregulated genes in αRGCs, , which encodes the two-pore domain leak potassium channel TASK3. Our study reveals a limited transcriptomic impact of cholinergic signaling in the retina and instead of affecting all RGCs uniformly, these waves show subtle modulation of molecular programs in a type-specific manner. Spontaneous retinal waves are critical for the development of the mammalian visual system. However, their role in transcriptional regulation in the retina across the diverse retinal ganglion cell (RGC) types that underpin the detection and transmission of visual features is unclear. Using single-cell RNA sequencing, we analyzed RGC transcriptome from wild-type mice and mice with disrupted retinal waves. We identified several genes that show RGC-type-specific regulation in their expression, including multiple neuropeptides and ion channels. However, wave-dependent changes in the transcriptome were more subtle than developmental changes, indicating that spontaneous activity-dependent molecular changes in retinal ganglion cells are not primarily manifested at the transcriptomic level, suggesting that post-transcriptional mechanisms may be involved.
在发育早期，被称为视网膜波的相关活动会导致视网膜神经节细胞（RGCs）出现周期性去极化。缺乏烟碱型乙酰胆碱受体β2亚基的β2KO小鼠，可作为理解胆碱能波作用的模型。β2KO小鼠在视觉系统的多个发育过程中存在缺陷，包括RGC轴突向其主要脑靶标的视网膜定位和眼特异性精细化减少，以及对方向选择性的视网膜回路产生影响。然而，这种突变对单个功能性RGC类型中基因表达的影响仍不清楚。在这里，我们对出生后第一周结束时从野生型和β2KO小鼠（雌雄均有）分离出的RGC进行了单细胞RNA测序。我们发现，在β2KO小鼠中，控制RGC分化的程序未受影响，与正常出生后两天成熟过程中观察到的转录变化幅度相比，转录变化幅度较小。这与最近研究中在波破坏情况下下游视觉系统区域出现的大量转录组变化形成对比。总体而言，我们鉴定出约238个基因，其表达以细胞类型特异性方式发生改变。我们通过杂交和全细胞记录，聚焦于αRGCs中一个下调基因，即编码双孔结构域渗漏钾通道TASK3的基因，证实了这一结果。我们的研究揭示了胆碱能信号在视网膜中的转录组影响有限，这些波并非均匀地影响所有RGC，而是以细胞类型特异性方式对分子程序进行细微调节。自发视网膜波对哺乳动物视觉系统的发育至关重要。然而，它们在整个视网膜神经节细胞（RGC）类型（这些类型支持视觉特征的检测和传递）的视网膜转录调控中的作用尚不清楚。利用单细胞RNA测序，我们分析了野生型小鼠和视网膜波被破坏的小鼠的RGC转录组。我们鉴定出几个在表达上显示RGC类型特异性调控的基因，包括多种神经肽和离子通道。然而，转录组中依赖波的变化比发育变化更细微，这表明视网膜神经节细胞中依赖自发活动的分子变化并非主要在转录组水平上表现出来，提示可能涉及转录后机制。
