Inhibition shapes activity and signal processing in neural networks through numerous mechanisms mediated by many different cell types. Here, we examined how one type of GABAergic interneuron in the retina, the A17 amacrine cell, influences visual information processing. Our results suggest that A17s, which make reciprocal feedback inhibitory synapses onto rod bipolar cell (RBC) synaptic terminals, extend the luminance range over which RBC synapses compute temporal contrast and enhance the reliability of contrast signals over this range. Inhibition from other amacrine cells does not influence these computational features. Although A17-mediated feedback is mediated by both GABAA and GABAC receptors, the latter plays the primary role in extending the range of contrast computation. These results identify specific functions for an inhibitory interneuron subtype, as well as specific synaptic receptors, in a behaviorally relevant neural computation.

中文翻译：

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突触抑制调节视网膜的对比度计算


抑制通过许多不同细胞类型介导的多种机制塑造神经网络中的活动和信号处理。在这里，我们研究了视网膜中一种 GABA 能中间神经元（A17 无长突细胞）如何影响视觉信息处理。我们的结果表明，A17 在杆状双极细胞 (RBC) 突触末端上形成相互反馈抑制性突触，扩展了 RBC 突触计算时间对比度的亮度范围，并增强了在此范围内对比度信号的可靠性。其他无长突细胞的抑制不会影响这些计算特征。虽然 A17 介导的反馈是由 GABA 介导的一个和伽马氨基丁酸C受体，后者在扩展对比度计算范围方面起主要作用。这些结果确定了行为相关神经计算中抑制性中间神经元亚型以及特定突触受体的特定功能。