Expression of vesl-1S/homer-1a, a gene associated with long-term potentiation, in the brain of the epileptic EI mouse.

The El mouse is an animal model for hereditary epilepsy. It undergoes a convulsive seizure lasting 10-30 s after vestibular stimulation, such as "tossing-up". To better characterize the effects of seizure activity in the El mouse, we examined the expression profile of vesl-1S/homer-1a mRNA in the brain. It has been shown that this mRNA is expressed after long-term potentiation or seizures induced by electrical or pharmacological stimulations. The basal level of vesl-1S mRNA was very low even in seizure-susceptible El mice. The El mouse hippocampus, but not that of ddY mice, showed a remarkable increase in vesl-1S mRNA expression in the dentate granule cell layer after seizure induced by "tossing-up". The mRNA remained for about 3 h after the seizure and disappeared after 8 h.