Immunomorphologic assessment of changes in functional astroglial proteins in a kainate-induced hippocampal sclerosis model

Introduction. Astrocytes are involved in mediator metabolism, neuroplasticity, energy support of neurons and neuroinflammation, and this determines their pathogenetic role in epilepsy. Aim. This study aimed at evaluating region-specific changes in the distribution of functional astroglial proteins in reactive astrocytes in a kainate-induced model of mesial temporal lobe epilepsy. Materials and methods. The localization and expression of functional astroglial proteins (i.e. aquaporin-4, connexin-43, EAAT1/2, and glutamine synthetase) in the hippocampus CA3 region, dentate gyrus, and stratum lucidum layer were evaluated by immunofluorescence 28 days after intra-hippocampal administration of kainic acid to animals. Results. Changes were heterogeneous in different hyppocampus subregions. Astrocytes of the stratum lucidum associated with mossy fibers showed the highest vulnerability and decreased content and/or disturbed localization of the channels and transporters that form membrane complexes in the processes. Disturbances in homeostatic functions of astrocytes aggravated the adverse processes both on the side where the toxin was injected and in the contralateral hippocampus.