Transparent Multi-Suction Electrode Arrays for in vitro Neural Network Investigations

Abstract

Large-scale multisite electrophysiology recordings with high temporal resolution are essential to discover neural circuitry and elucidate their structurefunction relationship. We contribute to this effort by combining multielectrode arrays (MEAs) with through pore arrays in quartz substrates to create multisuction electrode arrays. The MEA allows for multisite extracellular recordings from neural tissue while the through pore array permits suction to be applied to the tissue to form more intimate contact with the electrodes. We successfully recorded from mouse hippocampi, mouse retina, and leech segmental ganglia. Hippocampus and retina tissue show at least a 50% increase in S/N and twofold increase in detectable spikes following suction. (Interestingly, spiking activity and S/N of spikes in leech ganglia mostly do not increase after applied suction, suggesting sources deeper in the tissue.) Finally, we demonstrate optical imaging through the transparent substrate to visualize the neurons at the electrode interface simultaneously with electrophysiology recordings. This technology will facilitate the combination of optical-based measurements such as voltage-sensitive dye imaging with multisite electrophysiological recordings with high temporal resolution of neuronal networks in a wide range of vertebrate and invertebrate preparations, at the single spike level.