Febrile convulsions in inbred strains of mice susceptible and resistant to audiogenic seizures.

The incidence of febrile convulsions was determined in six inbred strains of mice at four ages. Febrile convulsions were elicited by placing the mice in a cylinder with the air temperature raised to 51 +/- 2 degrees C; this elevated the mouse's body and brain temperature to between 40 and 46 degrees C. The strains used were DBA/2Bg, DBA/1Bg, DBA/1Bg-ras, C57BL/10Bg, C57BL/6Bg, and C57BL/6Bg-Gad-1 alpha; the ages were 21 +/- 1, 29 +/- 1, 59 +/- 1, and 119 +/- 1 days of age. DBA/2Bg, DBA/1Bg, and C57BL/6Bg-Gad 1 alpha are audiogenic seizure susceptible at 21 +/- 1 and 29 +/- 1 days of age, but not at 59 +/- 1 and 119 +/- 1 days of age; whereas C57BL/10Bg, C57BL/6Bg, and DBA/1Bg-ras are audiogenic seizure resistant at all ages. Mice of both sexes, all strains, and all ages had a febrile convulsion and died. Thus, in inbred mice, there does not appear to be either a genetic or developmental correlation between audiogenic seizures and febrile convulsions. This finding may be contrasted with that in other studies showing a correlation between susceptibility to audiogenic seizures and to either electroshock convulsions or chemoconvulsions. However, there are subtle strain and age variants in susceptibility to febrile convulsions of these mice.