Lee Meng-Jung, Zeck Günther
Neurophysics, NMI Natural and Medical Sciences Institute at the University Tübingen, Reutlingen, Germany.
Graduate School of Neural Information Processing, International Max Planck Research School, Tübingen, Germany.
Front Neurosci. 2020 Nov 19;14:563964. doi: 10.3389/fnins.2020.563964. eCollection 2020.
The mammalian retina processes sensory signals through two major pathways: a vertical excitatory pathway, which involves photoreceptors, bipolar cells, and ganglion cells, and a horizontal inhibitory pathway, which involves horizontal cells, and amacrine cells. This concept explains the generation of an excitatory center-inhibitory surround sensory receptive fields-but fails to explain the modulation of the retinal output by stimuli outside the receptive field. Electrical imaging of light-induced signal propagation at high spatial and temporal resolution across and within different retinal layers might reveal mechanisms and circuits involved in the remote modulation of the retinal output. Here we took advantage of a high-density complementary metal oxide semiconductor-based microelectrode array and investigated the light-induced propagation of local field potentials (LFPs) in vertical mouse retina slices. Surprisingly, the LFP propagation within the different retinal layers depends on stimulus duration and stimulus background. Application of the same spatially restricted light stimuli to flat-mounted retina induced ganglion cell activity at remote distances from the stimulus center. This effect disappeared if a global background was provided or if gap junctions were blocked. We hereby present a neurotechnological approach and demonstrated its application, in which electrical imaging evaluates stimulus-dependent signal processing across different neural layers.
一条垂直兴奋性途径，涉及光感受器、双极细胞和神经节细胞；另一条水平抑制性途径，涉及水平细胞和无长突细胞。这一概念解释了兴奋性中心-抑制性外周感觉感受野的产生，但无法解释感受野之外的刺激对视网膜输出的调制。以高空间和时间分辨率对不同视网膜层内及层间光诱导信号传播进行电成像，可能会揭示参与视网膜输出远程调制的机制和回路。在此，我们利用基于高密度互补金属氧化物半导体的微电极阵列，研究了局部场电位（LFP）在垂直方向的小鼠视网膜切片中的光诱导传播。令人惊讶的是，LFP在不同视网膜层内的传播取决于刺激持续时间和刺激背景。将相同的空间受限光刺激施加于平铺的视网膜，会在远离刺激中心的远距离处诱导神经节细胞活动。如果提供全局背景或阻断缝隙连接，这种效应就会消失。我们在此提出一种神经技术方法并展示了其应用，即通过电成像评估不同神经层间依赖刺激的信号处理过程。
