Interpretation of the filtered 100- to 1000-Hz electroretinogram

We examined the possibility that the 100- to 1000-Hz oscillatory potentials could represent the derivative version of the 1-1000-Hz electroretinogram. Corneal electroretinograms were recorded from rabbits by means of bandwidths of 1-1000 Hz, 10-1000 Hz, 30-1000 Hz and 100-1000 Hz (6 dB of attenuation). Derivatives of the 1- to 1000-Hz electroretinogram had a waveform similar to the 100- to 1000-Hz signals, but of larger amplitude (21.9% +/- 16.7% larger, n = 16). Similarly, integration of the 100- to 1000-Hz signal resulted in a waveform whose amplitude was 60% of the original 1- to 1000-Hz electroretinogram. Our results suggest that some aspect of the morphologic changes seen when the low-frequency cutoff of the recording bandwidth of the ERG is increased from 1 Hz to 100 Hz could be explained with a simple derivative model. The oscillatory potentials may be significant contributors to the morphogenesis of the 1- to 1000-Hz electroretinogram.