Effect of body temperature on electroretinogram of mice.
OBJECTIVE
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.
Mizota
Atsushi
A
Department of Ophthalmology and Visual Science, Graduate School of Medicine, Chiba University, Japan. mizota@ophthalm.m.chiba-u.ac.jp
Adachi-Usami
Emiko
E
D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D003080:Cold Temperature; D003623:Dark Adaptation; D004596:Electroretinography; D051379:Mice; D008807:Mice, Inbred BALB C; D012160:Retina / Q000502:physiology*