Purpose: To investigate the ERG alterations induced by changes in body temperature in mice.
Methods: Three-week-old BALB/c mice were used. Rectal temperature was measured with a digital thermometer and taken as the body temperature. In experiment 1, the body temperature was kept at 33 degrees C, and the ERGs elicited by a constant stimulus intensity were recorded every 5 minutes. In experiment 2, the body temperature was lowered in five steps from 38 degrees C to 33 degrees C, 28 degrees C, 23 degrees C, and 18 degrees C. At each body temperature, ERGs elicited by different stimulus intensities were recorded.
Results: In experiment 1, the mean amplitudes and implicit times of both the a- and b-waves did not change significantly. In experiment 2, the amplitude of both the a- and b-waves decreased significantly with a decrease in body temperature, and the implicit times of the a- and b-waves were prolonged with a decrease in body temperature.
Conclusions: Body temperature greatly affects the amplitude and timing of the ERG. Great care must be taken to maintain as normal a body temperature as possible when using the ERG to evaluate the retina, especially in small animals such as mice.