Inherited and seizure-induced abnormalities in the temporal cortex astroglia of Krushinsky-Molodkina audiogenic rats: A pilot study.

Abstract

The role of astrocytes in the pathogenesis of temporal lobe epilepsy (TLE) is intensively studied. Here, we present a pilot study of astrocytes in the temporal cortex of Krushinsky-Molodkina (KM) rats, which are genetically prone to audiogenic seizures (AGS) and may be used as a model of TLE when exposed to audiogenic kindling. Naïve KM rats (with no AGS) were compared to Wistar rats to disclose the inherited abnormalities, and KM rats after 14-day audiogenic kindling were compared to naïve ones to determine TLE effects. Our results demonstrated that in the temporal cortex of naïve KM rats, the population of ALDH1L1-positive astrocytes was unaltered, while GFAP-positive astrocytes were localized only in the outer layers. Nuclear factor IA (NFIA)-positive astrocytes were distributed evenly, but their number was also lower. In addition, decreased aquaporin 4 and Kir4.1 were revealed indicating defective water and potassium homeostasis. These data point on genetically determined disfunction of cortex astroglia associated with inherited epileptic predisposition. After audiogenic kindling, KM rats still demonstrated no changes in ALDH1L1 expression, however, exhibited increased number of NFIA-positive astrocytes in the temporal cortex and upregulation of GFAP, aldolase C, and glutamine synthetase. Meanwhile, kindling further exacerbated the basal deficits of aquaporin 4 and Kir4.1.