Remodelling of retinal on- and off-bipolar cells following experimental retinal detachment.

BACKGROUND To study the response of ON and OFF bipolar cells in experimental retinal detachment. METHODS Domestic cat retinas were detached for 7 days. The retinas were prepared for immunocytochemical staining with antibodies to Go alpha (α), glutamate transporter GLT-1, protein kinase C and rod opsin, which serve as markers for ON bipolar cells, OFF bipolar cells, rod bipolar cells and rod photoreceptors, respectively. Both sections and whole-mounts were labelled with antibodies to Goα and GLT-1. RESULTS Following 7 days of detachment, ON bipolar cell processes extended into the outer nuclear layer and had neurites extending beyond their target layer into the inner plexiform layer. In contrast, OFF bipolar cell processes were reduced in the outer plexiform layer following detachment. CONCLUSION ON and OFF bipolar cells undergo significant remodelling of their processes in response to retinal detachment, and the ON and OFF pathways may be differentially affected. The remodelling may be due to morphological changes that have previously been shown to occur in photoreceptor synaptic terminals or as a result of loss of synaptic connections due to photoreceptor cell death.