Adaptation of visual responses in degenerating rd10 and healthy mouse retinas during ongoing electrical stimulation

Visual adaptation is a physiological and perceptual process by which the visual system adjusts to changes in the environment or visual stimuli. This process is fundamental to how we perceive the world around us and allows our visual system to efficiently encode and process visual information. The retina incorporates adaptation within its dozens of functionally distinct retinal ganglion cell types. Meanwhile, the field of retinal prostheses is increasing its understanding of electrical adaptation and cell-specific stimulation. However, very little is known about the interaction of visual and electrical stimulation on the adaptation of retinal ganglion cell types.

Recording with a microelectrode array (MEA), we presented an ON and OFF full-field, visual stimulus to characterize various visual response parameters in healthy and degenerating rd10 mouse retinas. We then evaluated visual response changes before and after blocks of monophasic voltage-controlled electrical pulse stimulation.

A history of electrical stimulation strengthened visual responses in WT retina, even when changes attributable to in vitro visual adaptation were considered. In rd10 retinas, electrical adaptation counteracted the baseline in vitro visual adaptation. In all cases, adaptation often affected the on and off visual response components differentially. Consequently, the ON/OFF classification of individual cells changed because of adaptation.

Electrical stimulation-induced changes in the retina should be considered in the encoding of visual stimuli by retinal prosthetic devices. In vitro investigations for bionic vision should strive to probe electrical responsiveness after adaptation to ongoing electrical stimulation has achieved a steady state.