This protocol details a method for isolating retinal tissue from adult rats as an organotypic culture to study neurobiological processes in mature tissue. It combines the efficiency and control common to in vitro techniques with close imitation of the in vivo environment. Eyes from adult rats are enucleated and the neural retina is isolated. Tissue is cut into quarters, yielding eight retinal explants per animal, and cultured at a fluid/air interface on organotypic culture membranes. Explantation can be accomplished in thirty minutes per animal. Tissue is nourished by a serum-free medium and can be viably maintained for at least two weeks ex vivo. Protocols are provided that describe histological processing, including techniques for whole-mount and cross-sectional immunohistochemical labelling. In addition, methods for simulating intraocular cell transplantation and pharmacological screening for neuroprotective therapies are also provided.