Background: Aim of this study was to investigate the retrograde axonal transport from optic nerve (ON) to retinal ganglion cell (RGC) in two animal models: in Royal College of Surgeons (RCS) rats, a rat model for retinal degeneration, and in a rat model for glaucoma induced by elevated intraocular pressure (IOP).
Methods: To carry out this study, dextran tetramethylrhodamine (DTMR--an hydrophilic neurotracer dye) was injected into the ON; 24 hrs later, the retina was removed and the number of labeled RGCs of the experimental rats was counted and compared.
Results: The results of these studies showed that the number of fluorescent-labeled RGCs in RCS rats and in rats with elevated IOP was reduced compared to the number of labeled RGCs of their respective controls.
Conclusion: Our findings suggest that RCS rats are characterized not only by loss of photoreceptor cells but also by functional deficits of RGCs.