[Morphofunctional changes in field CA1 of the rat hippocampus after pentylenetetrazole and lithium-pilocarpine induced seizures].

Animal models of epilepsy are very diverse and are used to elucidate the mechanisms underlying epileptogenesis and seizures. A single administration of pentylenetetrazole (PTZ) induces seizures, however it does not increase risk of further development of epilepsy. Pilocarpine immediately after injection evokes status epilepticus and after a latent period spontaneous convulsions develop in animals, i. e., the drug initiates the process of epileptogenesis. Assuming that in the PTZ model morphofunctional changes are mainly transient whereas changes in the lithium-pilocarpine (PC) model can indicate development of the brain epileptizationm, we compared morphological and functional characteristics in field CA1 of the hippocampus in a control and two groups of experimental animals 24 h after administration of convulsants. We revealed changes specific to the PC model and indicating the process of neurodegeneration: a decrease of the cell density, an altered NeuN expression, and an increase of the proapoptotic protease caspase-3 activity. A characteristic feature of the PTZ model was appearance of hyperchromic neurons with normal viability. In both models expression of the excitatory amino acids carrier EAAT1 increased by about 40% as compared to control. These morphofunctional correlates of reversible changes in the nervous tissue, caused by the convulsive state, and the early disturbances leading to the long-term brain epileptization can be used as indicators for evaluating therapeutic potential of novel anticonvulsive drugs.