Comparison of Oscillatory Rhythm in Retinal Ganglion Cell Activities Between rd1 and rd10 Mice

Abstract

Purpose: : Rd1

Methods: : Without any stimulus, spontaneous extracellular action potentials are recorded by 8 × 8 MEA from the RGC in the in vitro whole mount retina. Postnatal 4 weeks and 8 weeks rd1 and4 weeks and 10 weeks rd10 mice were used. Fourier transform was performed for oscillatory rhythm detection.

Results: : In rd1 mice, previously recognized ~ 10 Hz rhythm in field potential (slow wave component; SWC) was observed and this was shown to result in rhythmic bursting of spontaneous spikes of RGCs. In 4 weeks and 8 weeks rd1 mice, there is no statistical difference between the frequency of SWC and spike [p>0.05; 4 weeks: spike 9.3±0.9 Hz (n=40), SWC 9.3±1.3 Hz (n=15); 8 weeks: spike 10.0±1.3 Hz (n=87), SWC 10.9±0.8 Hz (n=10)]. While in 4 weeks and 10 weeks rd10 mice, the frequency of RGC spike and SWC shows significant difference [p<0.001; 4 weeks: spike 5.5±1.3 Hz (n=59), SWC 10.8±3.1 Hz (n=14); 8 weeks: spike 6.8±3.8 Hz (n=79), SWC 10.5±2.7 Hz (n=14)].

Conclusions: : The results suggest that with the progress of degeneration, the spike frequency shows hyperactivity and it become synchronized with the frequency of SWC.

Keywords: ganglion cells • retina • retinal degenerations: hereditary