Coding Properties of Mouse Retinal Ganglion Cells with Dual-Peak Patterns with Respect to Stimulus Intervals.

How visual information is encoded in spikes of retinal ganglion cells (RGCs) is essential in visual neuroscience. In the present study, we investigated the coding properties of mouse RGCs with dual-peak patterns with respect to visual stimulus intervals. We first analyzed the response properties, and observed that the latencies and spike counts of the two response peaks in the dual-peak pattern exhibited systematic changes with the preceding light-OFF interval. We then applied linear discriminant analysis (LDA) to assess the relative contributions of response characteristics of both peaks in information coding regarding the preceding stimulus interval. It was found that for each peak, the discrimination results were far better than chance level based on either latency or spike count, and were further improved by using the combination of the two parameters. Furthermore, the best discrimination results were obtained when latencies and spike counts of both peaks were considered in combination. In addition, the correct rate for stimulation discrimination was higher when RGC population activity was considered as compare to single neuron's activity, and the correct rate was increased with the group size. These results suggest that rate coding, temporal coding, and population coding are all involved in encoding the different stimulus-interval patterns, and the two response peaks in the dual-peak pattern carry complementary information about stimulus interval.

视觉信息如何在视网膜神经节细胞（RGCs）的脉冲中编码在视觉神经科学中至关重要。在本研究中，我们针对视觉刺激间隔研究了具有双峰模式的小鼠视网膜神经节细胞的编码特性。我们首先分析了反应特性，观察到双峰模式中两个反应峰的潜伏期和脉冲数量随着之前的光熄灭间隔呈现出系统性变化。然后我们应用线性判别分析（LDA）来评估两个峰的反应特征在关于之前刺激间隔的信息编码中的相对贡献。结果发现，对于每个峰，基于潜伏期或脉冲数量的判别结果都远优于随机水平，并且通过结合这两个参数进一步提高了判别效果。此外，当结合考虑两个峰的潜伏期和脉冲数量时，获得了最佳的判别结果。另外，当考虑视网膜神经节细胞群体活动而非单个神经元活动时，刺激判别的正确率更高，并且正确率随着群体规模的增大而提高。这些结果表明，频率编码、时间编码和群体编码都参与了对不同刺激间隔模式的编码，并且双峰模式中的两个反应峰携带了关于刺激间隔的互补信息。