Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel.
Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
Trends Neurosci. 2018 Apr;41(4):224-237. doi: 10.1016/j.tins.2018.01.009. Epub 2018 Feb 14.
The ability of the retina to adapt to changes in mean light intensity and contrast is well known. Classically, however, adaptation is thought to affect gain but not to change the visual modality encoded by a given type of retinal neuron. Recent findings reveal unexpected dynamic properties in mouse retinal neurons that challenge this view. Specifically, certain cell types change the visual modality they encode with variations in ambient illumination or following repetitive visual stimulation. These discoveries demonstrate that computations performed by retinal circuits with defined architecture can change with visual input. Moreover, they pose a major challenge for central circuits that must decode properties of the dynamic visual signal from retinal outputs.
视网膜适应平均光强和对比度变化的能力是众所周知的。然而,经典理论认为,适应会影响增益,但不会改变给定类型的视网膜神经元所编码的视觉模式。最近的发现揭示了小鼠视网膜神经元出人意料的动态特性,这对这一观点提出了挑战。具体来说,某些细胞类型会根据环境光照的变化或重复的视觉刺激而改变它们所编码的视觉模式。这些发现表明,具有特定结构的视网膜电路所执行的计算可以随视觉输入而改变。此外,它们对中枢电路构成了重大挑战,中枢电路必须从视网膜输出中解码动态视觉信号的特性。