The effect of body temperature on the murine electroretinogram

Purpose: To study the effect of body temperature on the murine electroretinogram (ERG). Methods: The corneal ERG elicited by a strobe flash from dark-adapted mice was recorded using a saline wick electrode while measuring rectal temperature continuously. The mouse was placed within a cylindrical coil of tubing through which water circulated from a temperature controlled bath. The body temperature of the mouse was changed stepwise between 30 and 37°C. Results: ERGs of approximately normal configuration were recorded at body temperature ranging between 30 and 37°C. The maximum amplitude of the a- and b-waves varied linearly with temperature. The rate of change of b-wave amplitude was about 100 V/degree. At 30°C, maximum b-wave amplitude was about 400 V; at 37°C it was about 1000 V. A change in body temperature produced a rapid change in ERG amplitude. Conclusion: The murine ERG is very sensitive to changes in temperature. In order to monitor the ERG accurately over time, continuous recording of body temperature is essential.