Electrophysiological properties of cultured hippocampal neurons from Wistar Audiogenic Rats

The main goal of this work was to analyze the electrophysiological properties of cultured hippocampal neurons from a particular epileptic rat strain, called Wistar Audiogenic Rats (WAR). The whole-cell patch-clamp technique was used to record both active and passive membrane responses in an attempt to detect alterations in their characteristics in relation to controls from Wistar rats. Neurons from WARs show a significant reduction in the magnitude of the inhibitory GABAergic currents (∼45%), in spite of maintaining a normal level of the excitatory glutamatergic currents. In addition, the magnitude of potassium currents, measured at +80 mV, is reduced by about 30% in comparison to controls. Surprisingly, we also found important changes in the passive cellular properties in WAR neurons such as membrane potential (−50.0 mV in WARs and −63.1 mV in controls) and input resistance (647 MΩ in WARs and 408 MΩ in controls). The changes described here, could be the basis of the neurophysiological and behavioral alterations present in these hyperexcitable animals, contributing to a better understanding of epileptogenesis in this particular animal model.