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

Exp Neurol. 2013 Sep:247:314-27. doi: 10.1016/j.expneurol.2013.01.029. Epub 2013 Feb 4.

Abstract

Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy, characterized by hippocampal sclerosis and memory deficits. It is well-documented that intrinsic neuronal oscillations and provided by them communications between brain structures are of importance for cognition. Epilepsy disturbs these brain rhythms and presumably therefore affects memory. 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.

Keywords: Animal models; EEG; Epilepsy; GABA; GABAergic cells; HCN; Hippocampus; Ih; MEG; MSDB; Rhythmic bursting; Seizures; Septum; TLE; Theta oscillations; electroencephalogram; gamma-aminobutyric acid; hyperpolarisation-activated cyclic nucleotide-gated channel, AD, Alzheimer's disease; hyperpolarisation-activated non-selective cation current; magnetoencephalogram; medial septal-diagonal band complex; temporal lobe epilepsy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Epilepsy, Temporal Lobe / pathology*
  • Hippocampus / physiopathology*
  • Humans
  • Neural Pathways / physiology*
  • Septum of Brain / physiopathology*
  • Theta Rhythm / physiology*