Bi-directional electrical recording and stimulation of the intact retina

Abstract Electrophysiological investigations of intact neural circuits are challenged by the gentle and complex nature of neural tissues. Bi-directional electrophysiological interfacing with the retina, in its intact form, is particularly demanding and currently there is no feasible approach to achieve such investigations. Here we present the use of novel soft multi electrode arrays for bi-directional electrophysiological study of the intact retina. To this aim, soft electrode arrays, suitable for stable electrical interfacing with the retina, were developed and tested. The soft probes were designed to accommodate the curvature of the retina in the eye and offer a unique opportunity to study the retina in its intact form. For the first time, we show both electrical recording and stimulation capabilities from the intact retina. In particular, we demonstrate the ability to map retina responses to electrical stimulation in order to reveal conspicuously, stable, direct and indirect responses. These results suggest that intact retinas retain better stability and robustness than ex-vivo retinas.