Disturbances of septohippocampal theta oscillations in the epileptic brain: Reasons and consequences

Here we review studies on cellular and systemic levels devoted to the TLE-induced disturbance of theta oscillations in the septohippocampal system. Special attention is paid to the role of damage of septal and hippocampal GABAergic cells in theta activity abnormalities. We also compare differences between native (in vivo) theta oscillations with those obtained in in vitro preparations of hippocampus and medial septum and find that in vitro they resemble epileptiform activity in some respects.