Accumulation of microtubule-associated proteins in the hippocampal neurons of seizure-sensitive gerbils

We have carried out a chronological and comparative analysis of microtubule-associated protein 1A (MAP1A) and microtubule-associated protein 2 (MAP2) immunoreactivities in the hippocampi of seizure-resistant (SR) and seizure-sensitive (SS) gerbils. These animals represent excellent genetic models of epilepsy associated with different sequelae of spontaneous seizures. Both MAP1A and MAP2 immunoreactivities were detected in the granule cell layer and in the hilar neurons of SR gerbils. In contrast with the SR gerbils, some neurons containing MAPs immunoreactivities were scattered in the molecular layer of the dentate gyrus as well as being concentrated in the hilar neurons in the SS gerbils. An increase in MAP1A immunoreactivity was evident in the perikarya of the dentate gyrus at 30 min postictal, whereas MAP2 immunoreactivity decreased. MAP1A immunoreactivity in the hilar neurons declined significantly by 3 h postictal, whereas MAP2 immunoreactivity increased. These results suggest that the immunoreactivity of MAPs in the hippocampal complex differs between SR and SS gerbils, and that this difference may be the results of seizure activity.