[Induction of NO-synthase and glial fibrillary acidic protein in astrocytes of the temporal cortex in rats with audiogenic epileptiform reaction].

The localization of NADPH-diaphorase (NADPH-d), inducible NO-synthase (iNOS) and glial fibrillary acidic protein (GFAP) was studied in the astrocytes of the temporal cortex in rats of Krushinsky-Molodkina strain which are genetically prone to audiogenic seizures. The seizure was evoked by thrice-repeated acoustic stimulation. Wistar rats and acoustically untreated seizure-free Krushinsky-Molodkina rats were used as a control. The foci of brain damage were consistently found in the neocortex of the animals with audiogenic seizures. Epileptic foci, 300-400 microm in diameter, were localized in layers III-V; they were found to consist of the clusters of NADPH-d-positive astrocytes and to be present in both hemispheres. In the foci of cortical damage astrocytes expressed iNOS and an elevated level of GFAP. The number of GFAP-immunopositive astrocytes in the foci of damage was increased by 25-37% compared to the control and to undamaged areas of the cortex. Astrocyte NOS and GFAP induction found in this work, suggests the participation of glia in compensatory NO-dependent mechanisms, that are formed in the damage foci of neocortex during the audiogenic seizures.