Mice were euthanized with intraperitoneal injection of Nembutal, and either enucleated immediately or transcardially perfused with Ringer’s solution followed by 4% paraformaldehyde (PFA) in PBS. Eye cups were removed and fixed in 4% PFA on ice for 1 hour, followed by dissection and post-fixation of retinas for an additional 30 minutes, then rinsed with PBS. Brains were post-fixed in 4% PFA at 4°C overnight. Animal procedures were in compliance with the US National Institutes of Health Guide for the Care and Use of Laboratory Animals and approved by the Animal and Care and Use Program at Harvard University.
