Effects of interleukine-10 on the Epileptiform activity development in the hippocampus induced by brief hypoxia, bicuculline and electrical kindling

The comparative effects of anti inflammatory cytokine interleukin-10 on the epileptiform activity development in CA1 hippocampal neurons were studied in different functional models of epileptogenesis that are not accompanied the visible morphological disturbances in the brain cells: I - it? vitro hypoxic model in the rat hippocampal slices; 2 - in vitro disinhibitory model with using GABA(A) antagonist, bicuculline, in the rat hippocampal slices; 3 - partial hippocampal kindling model in freely moving rats. Interleukin-10 (I ng/ml) depressed the posthypoxic hyperexcitability in CA1 pyramidal neurons of the rat hippocampal slices through a decrease of the effectiveness of hypoxia to depresses the functional neuronal activity in the rat hippocampal slices during hypoxic episode. On the other hand, interleukin 10 (1 ng/ml) did not affect an initiation of epileptiform activity in CA1 pyramidal neurons of the rat hippocampal slices induced by bicuculline. Interleukin-10 (1 ng/5 mu l) applied to the dorsal hippocampUS in awake rats depressed an initiation of focal seizures ("ictal"-like components of afterdischarges) induced by hippocampal kindling during the first six hours after an application. However, this cytokine did not affect neither the duration of "interictal "-like component of afterdischarges nor motor seizure development. Thus, our findings showed that anti inflammatory cytokine interleukin-10, in addition to its antihypoxic action, exert the neuroprotective effect on the initiation of "ictal"-like, but not "interictal"-fike, epileptiform discharges.