The retina is an important in vitro model for the central nervous system. It is more readily accessible than most nervous tissue and is strong enough to remain intact during manipulations. The retina of the rabbit commonly contains no penetrating blood vessels. It is nurtured by diffusion from capillary networks on either side. For this reason, the tissue will survive and functions without circulating blood, as long as it is bathed in a medium that closely resembles in vivo conditions.
Ames' medium was formulated to support retinal tissue in relatively short-term culture. Rabbit retina has been incubated in Ames' medium for over 2 days with its metabolism and electrical responses to light stimuli well maintained. This mixture is a medium of choice for maintaining central nervous system tissue in vitro.