High-density Multielectrode Array Recordings of Retinal Waves Using An Electrophysiology Platform.

Spontaneous retinal waves are a hallmark of retinal network activity during development, playing a crucial role in the formation of the visual system by influencing the refinement of axons, permeability of vasculature, and overall maturation of neural circuits. These waves are commonly studied in ex vivo retinal preparations using multielectrode arrays (MEAs), which enable electrophysiological recordings of large populations of retinal ganglion cell (RGC) activity. MEA-based electrophysiology has become a powerful tool due to its ease of use to rapidly collect high-throughput data, thus making it ideally suited to study retinal activity in a variety of experimental conditions. In this protocol, we outline the critical steps for preparing retinal tissue for the acquisition of electrophysiological data using a High-Density MEA (HD-MEA) on an electrophysiology platform. The process begins with the careful isolation of intact retinas from neonatal animals under physiological conditions. Once prepared, the retina is carefully mounted onto an HD-MEA chip, which consists of a grid of 26,400 electrodes capable of performing simultaneous extracellular recordings from at least 1,000 RGCs. Recordings can last up to several hours. Ultimately, this methodological approach offers valuable applications in investigating retinal development, disease, and potentially cross-species comparative studies, contributing to broader advancements in neuroscience and vision research.