Abstract
How a population of retinal ganglion cells (RGCs) encodes the visual scene remains an open question. Going beyond individual RGC coding strategies, results in salamander suggest that the relative latencies of an RGC pair encodes spatial information. Thus a population code based on this concerted spiking could be a powerful mechanism to transmit visual information rapidly and efficiently. Here, we tested this hypothesis in mouse by recording simultaneous light-evoked responses from hundreds of RGCs, at pan-retinal level, using a new generation of large-scale, high density multielectrode array consisting of 4096 electrodes. Interestingly, we did not find any RGCs exhibiting a clear latency tuning to the stimuli, suggesting that in mouse, individual RGC pairs may not provide sufficient information. We show that a significant amount of information is encoded synergistically in the concerted spiking of large RGC populations. Thus, the RGC population response described with relative activities, or ranks, provides more relevant information than classical independent spike count- or latency- based codes. In particular, we report for the first time that when considering the relative activities across the whole population, the wave of first stimulus-evoked spikes (WFS) is an accurate indicator of stimulus content. We show that this coding strategy co-exists with classical neural codes, and that it is more efficient and faster. Overall, these novel observations suggest that already at the level of the retina, concerted spiking provides a reliable and fast strategy to rapidly transmit new visual scenes.
Significance statement: How the retina encodes the visual environment remains an open question. Using a new generation of large-scale high density multielectrode array, we show that in large populations of mammalian retinal ganglion cells (RGCs), a significant amount of information is encoded synergistically in the concerted spiking of the RGC population. Thus, the RGC population response described with relative activities, or ranks, provides more relevant information than classical neural codes such as independent spike count- or latency- based codes. In particular, and for the first time, we show that the wave of first stimulus-evoked spikes (WFS) across the whole population reliably encodes and rapidly transmits information about new visual scenes. This strategy of WFS could also apply to different sensory modalities.
Footnotes
↵1 Authors report no conflict of interest.
↵3 The research received financial support from the 7th Framework Program for Research of the European Commission (Grant agreement no 600847: RENVISION, project of the Future and Emerging Technologies (FET) program Neuro-bio-inspired systems (NBIS) FET-Proactive Initiative)) and the Wellcome Trust (grant number 096975/Z/11/Z).
↵*Co-first-author.
↵†Co-senior-author.
Jump to comment: