Changes in Functional Activity of Rabbit’s Retina During Flicker Photostimulation with Scale-free Dynamics

Abstract

Neuroplasticity-based stimulation therapy assists in restoring the visual system in neurodegenerative disorders. Scale-free fluctuations peculiar to healthy physiological rhythms disappear as the disease progresses. Fractal visual stimuli positively influence CNS plasticity and increase the efficiency of visual rehabilitation. To determine the effect of a lengthy course of fractal photostimulation (FS) on the electroretinogram (ERG) in healthy rabbits, a device for FS was created. For twelve healthy rabbits, 20-minute FS sessions were conducted once a day from 9 to 11 a.m., five times a week. Before and after 1, 4, and 12 weeks of FS, full-field ERGs, flicker ERGs, and the pattern-ERGs were registered. The observed positive impact of FS consisted of shortening peak latency of the maximal scotopic ERG b-wave and a significant increase in the amplitude of the cone ERG a- and b-waves and low-frequency flicker ERGs (p<0.05). For the first time, we describe the effect of FS on the ERG. The long-term FS does not impair retinal activity and can be safely used in the clinic. The dynamics of the positive influence of FS on retinal activity argue that the duration of the FS course of 1 to 4 weeks is optimal for subsequent studies.