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Updated: May 29, 2026

Implantation and Recording of Wireless Electroretinogram and Visual Evoked Potential in Conscious Rats
Published on: June 29, 2016
Comparison on photopic electroretinogram negative response between young and old Lewis rats
Yiqun Geng1, Hongling Chen, Lifang Liu
1Chinese Universtiy of Hong Kong Joint Shantou International Eye Center, Shantou, China.
Purpose:
To investigate and compare the latency and amplitude of the electroretinogram (ERG) photopic negative response (PhNR) between young and old Lewis rats.
Methods:
Thirteen Lewis rats were divided into two groups according to ages, young group (3-month old n=5) and old group (24 month old n=8). The ERGs of the left eyes were measured and the latency and amplitude of a-wave, b-wave and PhNRs were recorded and compared according to ages. The mean values between two groups were statistically analysed by t-test.
Results:
The latency of PhNRs were evidently prolonged in old group and showed significant difference (P<0.05). There was no statistically significant difference between two groups regarding the amplitude and latency, and no significant difference was noted in the amplitude of PhNRs.
Conclusion:
The prolonged latency of PhNR in aged rats possibly associate with the influence of aging upon retinal ganglion cell layer (RGCL).

