Purpose: To evaluate early stage retinal neurocircuitry remodeling in different retinal disease models.
Methods: RCS rats (retinitis pigmentosa animal model), db/db mice (diabetic animal model), and cats (physically induced detachment) were used in this experiment. Retinal ganglion cells were either retrogradely labeled with 8% biotinylated dextran-conjugated methylrhodamine or stained with two drops of 0.002% Acridine orange. Visual stimuli were generated by programming a graphics card. Single-unit visual responses from ganglion cells in a superfused, flattened eyecup preparation were recorded in vitro under visual control.
Results: The ganglion cell single unit visual response declined quickly over the course of retinal neurocircuitry remodeling in each animal model tested in this study. The deteriorated visual functions were reflected in progressive elevations in luminance threshold in the early stage of the remodeling. This was followed by deteriorations in the spatial frequency tuning and contrast responses. The ON channel was more susceptible to degeneration induced injury whereas OFF channel was less vulnerable.
Conclusions: The first definitive signs of retinal neurocircuitry remodeling in each of the tested retinal disease animals were elevations in luminance threshold and followed decreases in contrast responses. The ON channel is more vulnerable to degenerative retinal diseases than OFF channel.

Supported by NSFC Grant 60777001