Генерация тета-ритма в септо-гиппокампальной системе и эпилепсия

Abstract

Temporal lobe epilepsy is one of the most widespread forms of epilepsy characterized by the sclerosis of the hippocampus and memory deficit. Because it has been shown by numerous investigations that the hippocampal theta rhythm forms the basis of cognitive brain activity, the question as to how the development of pathology affects the formation of the theta rhythm generates considerable interest. A pacemaker of the hippocampal theta rhythm is the medial septal area, which, together with the hippocampus, is often considered as an integral septohippocampal system. The review summarizes the data on the functioning of the septohippocampal system at the cellular and systemic levels in the healthy brain and during the development of temporal lobe epilepsy. The data on the contribution of different cell populations of the medial septal area to the theta rhythm formation and their role in epileptogenesis are presented. Changes in interactions between the septum and the hippocampus in the epileptic brain are considered. The evidence presented suggests that one of the most important mechanisms of the generation of seizures and the development of chronic temporal lobe epilepsy is the disturbance of septohippocampal interactions. The evidence is presented indicating that the hippocampal network generates either the physiological theta rhythm or epileptiform theta oscillations depending on the conditions and the physiological state of the system. The protective role of the theta rhythm in epilepsy is discussed. An understanding of the mechanisms underlying the functioning of the septohippocampal system in the epileptic brain is necessary for the development of novel approaches to the treatment of this pharmacoresistant form of epilepsy.