Glucocorticoids alter recovery processes in the rat retina.

The effect of glucocorticoids on the electroretinogram (ERG) b-wave was studied in freely moving rats. b-Waves were evoked by flashes delivered by a light emitting diode implanted under the skin above the left eye. I.v. corticosterone and dexamethasone injection induced a transient increase in b-wave amplitude at 90 min. Retinal oscillatory potentials (OPs) were similarly enhanced. Pretreatment with a glucocorticoid receptor antagonist (RU 38486) abolished both increases. These results suggest that enhancements in retinal potentials may be the result of a glucocorticoid-induced facilitation of the processes under way in normal Müller cells following retinal excitation.