Aim: 

Experimental status epilepticus usually causes learning impairment. It is commonly connected with loss of hippocampal neurons. This damage is widely accepted as a reason of impaired learning. We tested whether disturbances of learning also occur without cell death and if it is possible to block their occurrence.

Methods: 

We developed other model of learning impairment in water maze. This impairment was evoked by one epileptic seizure elicited by Flurothyl.

Results: 

This seizure lasted maximally 3 minutes. We did not observe any morphological changes after the seizure. The learning could be preserved by hypoxic preconditioning (3 days prior the seizure) and the same effect occurred after the application of melatonin, reduced glutathione and tempol prior the seizure. We suppose that this effect is probably related to the scavenger activity of the substances. Pretreatment with melatonin 1h prior the hypobaric hypoxia decreased preconditioning effect.

Conclusion: 

Our results strongly support the possibility of involvement of free radicals in some functional changes caused by epileptic seizure and its role in preconditioning in the central nervous system.

Supported by Grant GA UK 104/2004/C/3rd Fac. Med. and Research Goal of Ministry of Education 0021620816