Tikidji-Hamburyan Alexandra, Reinhard Katja, Seitter Hartwig, Hovhannisyan Anahit, Procyk Christopher A, Allen Annette E, Schenk Martin, Lucas Robert J, Münch Thomas A
Retinal Circuits and Optogenetics, Centre for Integrative Neuroscience and Bernstein Center for Computational Neuroscience, University of Tübingen, Germany.
Current address: Dept. of Neurosurgery and Hansen Experimental Physics Laboratory, Stanford University, Stanford CA 94305, USA.
Nat Neurosci. 2015 Jan;18(1):66-74. doi: 10.1038/nn.3891. Epub 2014 Dec 8.
The collective activity pattern of retinal ganglion cells, the retinal code, underlies higher visual processing. How does the ambient illuminance of the visual scene influence this retinal output? We recorded from isolated mouse and pig retina and from mouse dorsal lateral geniculate nucleus in vivo at up to seven ambient light levels covering the scotopic to photopic regimes. Across each luminance transition, most ganglion cells exhibited qualitative response changes, whereas they maintained stable responses within each luminance. We commonly observed the appearance and disappearance of ON responses in OFF cells and vice versa. Such qualitative response changes occurred for a variety of stimuli, including full-field and localized contrast steps and naturalistic movies. Our results suggest that the retinal code is not fixed but varies with every change of ambient luminance. This finding raises questions about signal processing within the retina and has implications for visual processing in higher brain areas.
视网膜神经节细胞的集体活动模式，即视网膜编码，是更高层次视觉处理的基础。视觉场景的环境光照度如何影响这种视网膜输出？我们在高达七种环境光水平下，对离体的小鼠和猪视网膜以及活体小鼠的背外侧膝状核进行了记录，这些光水平涵盖了暗视觉到明视觉范围。在每个亮度转换过程中，大多数神经节细胞都表现出定性的反应变化，而在每个亮度范围内它们保持稳定的反应。我们通常观察到，在OFF细胞中ON反应的出现和消失，反之亦然。这种定性的反应变化在各种刺激下都会发生，包括全场和局部对比度变化以及自然电影。我们的结果表明，视网膜编码不是固定的，而是随着环境亮度的每一次变化而变化。这一发现引发了关于视网膜内信号处理的问题，并对大脑更高区域的视觉处理产生影响。
