Retinal Electrophysiology in Mice

The retinas of wild-type mice (C57BL/6J, Jackson Labs) were used for all experiments. The mice were dark adapted overnight and euthanized by cervical dislocation in accordance with all animal care standards provided by Northwestern University’s Institutional Animal Care and Use Committee. Lighting in animal facilities was kept on a 14/10 hour cycle, with lights on at 6:00 am. Typical retina in vitro times were 12:00 pm through 7:00 pm. For all experiments, mice of either sex (approximately 69% male), and ages P30-P90 were used; no differences in results were observed with sex or age. Eyes were dissected in oxygenated Ames medium at 32°C. Dissections were performed in complete darkness using infrared (IR, 900 nm) illumination and photo converters. In the experimental rig, retinas were mounted in a shallow dish, below a microscope objective and above a digital projector, in oxygenated Ames’ medium from Sigma-Aldrich (A1420) at 32°C at a flow rate of 10 ml/min. Two glass electrodes on headstage amplifiers were mounted on micromanipulators on either side. Cell-attached and current clamp experiments were performed as previously described^{26 (link)}.