Rapid global shifts in natural scenes block spiking in specific ganglion cell types

Abstract

The mammalian retina contains more than a dozen different ganglion cell types, each with dendrites ramifying at different strata within the inner plexiform layer (IPL) and each carrying a unique representation of the visual world. We studied the inhibitory and excitatory inputs, as well as the spiking output, of each of the rabbit retinal ganglion cell type during rapid global shifts in 'natural' videos designed to mimic saccadic eye movements. These shifts generated stratum-specific transient inhibitory activity, affecting only those ganglion cells whose dendrites ramify within the central strata of the IPL. The inhibition was GABA-mediated, acted both pre- and postsynaptically and was fast enough to either prevent or delay spiking. These findings indicate that the fast, transient elevation of visual threshold during rapid shifts in scene has a significant retinal component.