Lack of strain differences in spatial learning among seizure-prone and seizure-resistant mice

Learning rates were examined in the following inbred mice strains: DBA/2, C3H/He, C57B1/6J, E1, and ddY. DBA/2 mice become susceptible to audiogenic seizures after 2-3 weeks of age and E1 mice have generalized seizures in response to handling after 3 months of age, but the remaining three strains do not develop seizures. In this study, mice from all five strains underwent 32 training trials in a Morris water maze at 7-9 weeks of age. The seizure-prone DBA/2 and E1 mice, along with the nonepileptic ddY and C57B1/6J mice, exhibited learning at similar rates, but the nonepileptic C3H/He mice were unable to learn the water maze task, probably due to visual difficulties. In the C57B1/6J strain only, female mice learned the task significantly faster than males. There was no difference in the learning rate between the E1 strain and its parent ddY strain, or any correlation between spatial learning ability and kindling rates in these strains.