Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.23.168054v1?rss=1 Authors: Levine, J. N., Schwartz, G. W. Abstract: In the mouse, retinal output is computed by over 40 distinct types of retinal ganglion cells (RGCs) (Baden et al., 2016). Determining which of these many RGC types project to a retinorecipient region is a key step in elucidating the role that region plays in visually-mediated behaviors. Combiningretrograde viral tracing and single-cell electrophysiology, we identify the RGC types which project to the olivary pretectal nucleus (OPN), a major visual structure. We find that retinal input to the OPN consists of a variety of intrinsically-photosensitive and conventional RGC types, the latter a diverse set of mostly ON RGCs. Surprisingly, while the OPN is most associated with the pupillary light reflex (PLR) pathway, requiring information about absolute luminance, we show that the majority of the retinal input to the OPN is from single cell type which transmits information unrelated to luminance. This ON-transient RGC accounts for two-thirds of the input to the OPN, and responds to small objects across a wide range of speeds. This finding suggests a rolefor the OPN in visually-mediated behaviors beyond the PLR. Copy rights belong to original authors. Visit the link for more info