Early-life status epilepticus induces long-term deficits in anxiety and spatial learning in mice

One of the most devastating aspects of developmental epilepsy is the long-term impact on behavior. Children with epilepsy show a high co-morbidity with anxiety disorders and autism.

To examine whether early-life status epilepticus results in altered anxiety, repetitive behavior, social behavior, and learning and memory, we induced status epilepticus in male C57BL/6 mice on postnatal day (PD) 10. The mice received intraperitoneal injections of either kainic acid (2mg/kg) or 0.9% normal saline. We also included a nontreated control group. Kainic acid induced status epilepticus for approximately 1.5 hrs. At PD60, the adult mice were then tested in a battery of behavioral tasks, including open field activity, elevated-plus maze, light-dark test, marble burying, social chamber, social partition, conditioned fear, novel object recognition, and Morris water maze.

The early-life seizure group showed consistent increases in anxiety in the open field test (p < 0.05), elevated plus maze (p < 0.05), and light-dark task (p < 0.01). The seizure group showed significant (p < 0.01) impairment in the Morris water maze. There were no differences observed in marble burying, social partition, social chamber, novel object recognition, or delay fear conditioning tasks.

These results demonstrate that a single insult of status epilepticus during the neonatal period is sufficient to cause specific, long-term impairments in anxiety and spatial learning.