A flattened retina-eyecup preparation suitable for electrophysiological studies of neurons visualized with trans-scleral infrared illumination

We present an in vitro flattened retinal-scleral preparation suitable for e lectrophysiological studies from visually targeted amacrine and ganglion ce lls of the rabbit retina. In a newly designed superfusion chamber, the reti nal-scleral tissue is stained with Azure B allowing for imaging of neurons in the ganglion cell layer with an infrared (IR)-sensitive CCD camera via t rans-scleral IR illumination. Neurons can be visually identified and target ed for both extracellular and intracellular recordings made singly or in si multaneous pairs. The quality and stability of the recordings are excellent and the tissue remains viable for up to 10 h. This relatively simple prepa ration avoids the extensive surgical manipulations inherent to those based on isolated retinas or retinal slices. Moreover, the use of trans-scleral I R illumination rather than fluorescent dyes to visualize and target neurons allows for electrophysiological studies of the retina under controlled ada ptational states including dark-adapted conditions. (C) 2000 Elsevier Scien ce B.V. All rights reserved.