PT - JOURNAL ARTICLE AU - Geoffrey Portelli AU - John M. Barrett AU - Gerrit Hilgen AU - Timothée Masquelier AU - Alessandro Maccione AU - Stefano Di Marco AU - Luca Berdondini AU - Pierre Kornprobst AU - Evelyne Sernagor TI - Rank order coding: a retinal information decoding strategy revealed by large-scale multielectrode array retinal recordings AID - 10.1523/ENEURO.0134-15.2016 DP - 2016 May 13 TA - eneuro PG - ENEURO.0134-15.2016 4099 - http://www.eneuro.org/content/early/2016/05/12/ENEURO.0134-15.2016.short 4100 - http://www.eneuro.org/content/early/2016/05/12/ENEURO.0134-15.2016.full AB - 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.