Growth of postnatal rat retina in vitro. Development of neurotransmitter systems

In this study, we demonstrate that explanted neonatal rat retina can be mai ntained in culture for periods up to 3 weeks. The cultured retinas displaye d a distinct layering that was almost identical to litter-matched retinas o f the same age, bur the majority of the ganglion cells did not survive and photoreceptor outer segments did not develop properly. Distinct synaptophys in immunoreactivity was expressed in both the inner and outer plexiform lay ers of cultured retina and the pattern mimicked that one observed in vivo. After 2-3 weeks in vitro, the inner retina expressed immunoreactivities to various components of the cholinergic and nitrergic transmitter systems, in cluding nitric oxide activated cyclic GMP immunoreactivity. The investigate d cell populations displayed similar distribution patterns as in situ, but morphological differences appeared in vitro. Such differences were mainly o bserved as irregularities in the arborization patterns in the inner part of the inner plexiform layer. We suggest that these discrepancies may arise a s a result of reduced ganglion cell survival. Our observations demonstrate that some neurotransmitter systems develop in vitro and their neural circui try appears similar to the in vivo situation. The presence of synapses, rec eptor proteins and transmitter substances implies that neural communication can occur in cultured retinas. (C) 2000 Elsevier Science B.V. All rights r eserved.