We are excited to see our new work on avian retina up on bioRxiv!
Seifert M, Roberts PA, Kafetzis G, Osorio D, Baden T. Birds multiplex spectral and temporal visual information via retinal On- and Off- channels. bioRxiv 2022. https://www.biorxiv.org/content/10.1101/2022.10.20.513047v1
We find that birds use a fundamentally different strategy compared to mammals to communicate from the eye to the brain
Rather than neatly segregating information into neat and functionally opposite streams (On and Off, fast and sloww, greyscale and colour), most bird RGCs bunch the whole lot into single axons to “multiplex” the information.
This is energy expensive when considering spikes (mammals are great at saving energy here), but it is bandwidth efficient when considering limits on the optic nerve
We furhte posit that the bird strategy is the “original” one, shared with fish, reptiles and amphibians. The mammal strategy is probably derived, enabled by a radical simplification and reorganisation of circuits following the loss of 2 of the 4 original cones during the age of the dinosaurs