Genetic analysis of cerebellar lipids in mice susceptible to audiogenic seizures

The major neutral and acidic cerebellar lipids were studied in audiogenic seizure (AGS)-resistant C57BL 6 (B6) and AGS-susceptible DBA 2J (D2) mice. These cerebellar lipids were also studied in the D2.B6-Ias^b congenic mice and in the B6D2F₁ hybrids that are mostly AGS resistant. Except for the Ias^b gene, which inhibits AGS susceptibility, the D2.B6-Ias^b congenic mice are genetically similar to the D2 mice. Because subtle abnormalities in the chemical structure of membranes may underlie epilepsy, we wanted to determine if AGS susceptibility was associated with abnormalities in the distribution of cerebellar lipids. A new method for the analysis of total brain lipids was used in this study. Slight, but significant, differences were found between the B6 and D2 strains for the concentrations (μg/100 mg wet weight) of sphingomyelin, phosphatidylcholine, and cerebrosides. However, these differences may not be associated with differences in AGS susceptibility since the concentrations of these lipids in the AGS-resistant D2.B6-Ias^b and B6D2F₁ mice were more similar to the D2 than the B6 concentrations. The expression of Ias^b is not responsible for the lipid differences found between the B6 and D2 mice.