Data-driven models of optimal chromatic coding in the outer retina
Data-driven models of optimal chromatic coding in the outer retina
复制标题
外层视网膜最佳色彩编码的数据驱动模型
DOI：
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
R. Dickman
中科院分区：
文献类型：
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作者：
Luisa Ramirez;R. Dickman
参与颜色辨别的最外层视网膜回路的功能特性还不清楚。最近对斑马鱼的实验工作已经阐明了光感受器和水平细胞的体内活动作为刺激光谱的函数，突出了在视锥细胞和水平细胞之间的第一突触连接处出现的色对手信号。这些研究结果，以及观察到的缺乏缝隙连接，表明在斑马鱼早期产生颜色依赖性的机制是由抑制性反馈。我们讨论了所观察到的神经元活动的背景下，有效的编码的彩色信息，假设对手的彩色信号提供最佳的编码，最大限度地减少信号冗余。我们通过研究二色和三色外视网膜网络的动态特性来研究这些功能特性是否在不同物种中具有普遍性。我们的研究结果表明，占主导地位的抑制反馈机制提供了一个明确的编码的彩色刺激，而这个属性是不能保证在网络中有很强的兴奋性锥间连接，例如通过间隙连接。这为在斑马鱼视网膜最外层观察到缝隙连接的缺失提供了一个合理的解释。此外，我们的研究表明，最简单的斑马鱼类网络与占主导地位的抑制反馈能够最佳地编码彩色信息需要至少两个连续的抑制反馈层。最后，我们将斑马鱼启发的视网膜网络与具有不同视蛋白组合的网络的色彩编码性能进行了对比。我们发现，最佳的组合导致的色编码的改善只有13%相比，斑马鱼视蛋白，这表明斑马鱼视网膜执行接近最佳的编码的彩色信息在其栖息地。最近的实验工作已经证明，斑马鱼视网膜中的外部神经元回路使用颜色对手机制来编码和传输锥细胞和水平细胞之间的第一次突触接触的颜色信息。受这些发现的启发，我们提出了一个数据驱动模型来研究外视网膜网络的生理和动力学特性及其对脊椎动物视网膜回路颜色编码的影响。我们首先在一个大的参数空间中研究我们的模型，发现导致颜色对手信号的主要生物机制是由显性抑制反馈介导的，例如，通过水平的细胞突触连接。相反，视锥细胞之间的强耦合导致模糊的色编码，这在外层视网膜中是不期望的。然后，我们使用斑马鱼的实验数据参数化的模型和量化的色彩编码性能。我们的研究结果表明，具有抑制反馈的三色视网膜是非常有效的，并捕获了大部分典型的斑马鱼环境中的彩色信息方差。更具体地说，斑马鱼启发的视网膜网络之间的比较表明，斑马鱼视网膜电路是其自然色彩信息的接近最佳的色彩编码。
The functional properties of the outermost retinal circuits involved in color discrimination are not well understood. Recent experimental work on zebrafish has elucidated the in-vivo activity of photoreceptors and horizontal cells as a function of the stimulus spectrum, highlighting the appearance of chromatic-opponent signals at the first synaptic connection between cones and horizontal cells. These findings, together with the observed lack of gap junctions, suggest that the mechanism yielding early color-opponency in zebrafish is dominated by inhibitory feedback. We discuss the observed neuronal activity in the context of efficient codification of chromatic information, hypothesizing that opponent chromatic signals provide optimal codification, minimizing signal redundancy. We examine whether these functional properties are general across species by studying the dynamic properties of dichromatic and trichromatic outer retinal networks. Our findings show that dominant inhibitory feedback mechanisms provide an unambiguous codification of chromatic stimuli, whereas this property is not guaranteed in networks with strong excitatory inter-cone connections, for example via gap junctions. This provides a plausible explanation for the absence of gap junctions observed in the outermost zebrafish retinal layers. In addition, our study suggests that the simplest zebrafish-like network with dominant inhibitory feedback capable of optimally codifying chromatic information requires at least two successive inhibitory feedback layers. Finally, we contrast the chromatic codification performance of zebrafish-inspired retinal networks with networks having different opsin combinations. We find that optimal combinations lead to a chromatic codification improvement of only 13% compared with zebrafish opsins, suggesting that the zebrafish retina performs nearly optimal codification of chromatic information in its habitat. 2 Author summary Recent experimental work has evidenced that outer neuronal circuits in the zebrafish retina use color-opponent mechanisms to codify and transmit chromatic information at the first synaptic contact between cones and horizontal cells. Inspired by these findings, we propose a datadriven model to study physiological and dynamical properties of outer retinal networks and their implications for color codification across vertebrate retinal circuits. We first study our model in a large parameter space, finding that the primary biological mechanism leading to color-opponent signals is mediated by dominant inhibitory feedback, e.g., via horizontal cell synaptic connections. In contrast, strong coupling among cones leads to ambiguous chromatic codification, undesirable in the outer retina. Then, we parameterize the model using zebrafish experimental data and quantify its chromatic codification performance. Our results suggest that trichromatic retinas with inhibitory feedback are highly efficient and capture most of the chromatic information variance typical from zebrafish environments. More specifically, a comparison among zebrafish-inspired retinal networks suggests that zebrafish retinal circuits are near-optimal chromatic codification of their natural chromatic information.
影响因子：
33.6
作者：
W. Thoreson;D. Dacey
通讯作者：
W. Thoreson;D. Dacey
影响因子：
5.5
作者：
Chapot, Camille A.;Euler, Thomas;Schubert, Timm
通讯作者：
Schubert, Timm
脊椎动物视网膜中功能神经回路的结构。
影响因子：
4.4
作者：
Kolb,H
通讯作者：
Kolb,H