Differences in spike generation instead of synaptic inputs determine the feature selectivity of two retinal cell types

Retinal ganglion cells (RGCs) are the spiking projection neurons of the eye that encode different features of the visual environment. The circuits providing synaptic input to different RGC types to drive feature selectivity have been studied extensively, but there has been less research aimed at understanding the intrinsic prop-erties and how they impact feature selectivity. We introduce an RGC type in the mouse, the Bursty Sup-pressed-by-Contrast (bSbC) RGC, and compared it to the OFF sustained alpha (OFFsA). Differences in their contrast response functions arose from differences not in synaptic inputs but in their intrinsic properties. Spike generation was the key intrinsic property behind this functional difference; the bSbC RGC undergoes depolarization block while the OFFsA RGC maintains a high spike rate. Our results demonstrate that differ-ences in intrinsic properties allow these two RGC types to detect and relay distinct features of an identical visual stimulus to the brain.

Automated summary

The study reveals how the intrinsic properties of retinal ganglion cells affect feature selectivity. By comparing different types of RGCs, researchers found that differences in their intrinsic properties, rather than synaptic inputs, resulted in differences in contrast response functions.