15th International Congress of Histochemistry and Cytochemistry, Antalya, Türkiye, 18 - 21 Mayıs 2017, ss.409
AIM: GABA has been investigated widely in the studies for enlightening the mechanisms of epilepsy. Alterations in GABA levels were demonstrated in epileptic conditions. GAERS is a genetic model of absence epilepsy and has been used in studies comparing temporal lobe and absence epilepsies. The present study aimed to examine GABA density and synaptic length in the somatosensory cortex of GAERS after electrical kindling stimulations at the ultrastructural level. MATERIALS-METHOD: A total of 6 stimulations were applied to Wistar rats and GAERS for electrical kindling. Animals were sacrificed by perfusion fixation 1 hour after the last stimulation. Cortical tissues were routinely processed for transmission electron microscopy, and thin sections were obtained. Immunogold method was applied by using anti-GABA primary antibody and secondary IgG antibody conjugated to 10 nm gold particles. Ten micrographs were taken from each animal. GABA density and synaptic length in the GABAergic terminals were calculated by using NIH Image Analysis (Image J) program. Statistical analysis was performed using One-Way ANOVA and Tukey multiple comparison tests. RESULTS: It was found that the GABA density was significantly decreased, and the synaptic length was significantly increased in the Wistar kindling group, compared to the sham-operated Wistar control group. GABA density showed a tendency to decrease, and synaptic length to increase, in GAERS kindling group, compared to the sham-operated GAERS control group; however, the differences were not statistically significant. DISCUSSION: The reduction in GABA density in Wistar kindling group in the present study is in line with the previous studies demonstrating inhibitory cell loss in temporal lobe epilepsy. Decreased GABA in this group may have resulted in a compensatory increase in the synaptic length. On the other hand, a lack of significant reduction of GABA in the cortex of GAERS kindling group may be related to the resistance of this strain to kindling stimulations.