Retinal Isolation for Electrophysiology

Animals were dark-adapted overnight, deeply anaesthetized with isoflurane (Baxter), and euthanized via cervical dislocation. After bilateral enucleation, the eyes were submerged in bicarbonate-buffered Ames medium (~32°C, Sigma Millipore, 285–295 mOsm) continuously equilibrated with carbogen (95% O₂/5% CO₂). The cornea, lens, and iris were removed using small surgical scissors and forceps under a dissecting microscope (Zeiss) and infrared LED illumination (940 nm, ThorLabs), visualized through the microscope eyepieces with infrared image converters (BE Meyers). Retinas were either used immediately or left in their eyecups and stored for up to 6 hours at room temperature in light-proof chambers in carbogen-equilibrated Ames solution.