REVERSE INHIBITORY CONNECTIONS THROUGH GABA B-RECEPTORS SYNCHRONIZE INTERICTAL DISCHARGES IN THE CORTEX

Abstract

Modern experimental data show that interictal discharges consist of a short spike and a slow wave, which is regarded as a prolonged hyperpolarization. On the model of interictal discharges synchronization, a study of reciprocal inhibitory connections was carried out. In rats in light narcotic sleep, after application of GABA A-receptor blockers to the cortex, interictal discharges occurred in neighboring cortical areas independently of each other, and then synchronization occurred. In the experiments in which the interictal discharges occurred simultaneously, the durations of the slow wave (inhibitory phase) were the same. During the registration in these and other experiments, there was an increase in the time delay between the moments of interictal discharges generation. Under conditions of increased synchronization, the duration of the slow wave (inhibitory phase) of interictal discharges increased. Interictal discharges, which occurred first, had a longer duration of inhibition compared to the duration in the neighboring point, because the inhibition from the neighboring networks via feedback inhibitory connections is added to its own inhibition in the neuronal network. When excitation occurred, it was followed by inhibition via feedback, which limited the period of excitation, and thus created a temporary integration window, and this also happened in the neighboring neural networks of the cortex.