Epileptiform activity in rat hippocampus strengthens excitatory synapses.
Although epileptic seizures are characterized by excessive excitation, the role of excitatory synaptic transmission in the induction and expression of epilepsy remains unclear. Here, we show that epileptiform activity strengthens excitatory hippocampal synapses by increasing the number of functional (RS)-alpha-amino-3hydroxy-5methyl-4-isoxadepropionate (AMPA)-type glutamate receptors in CA3-CA1 synapses. This form of synaptic strengthening occludes long-term potentiation (LTP) and enhances long-term depression (LTD), processes involved in learning and memory. These changes in synaptic transmission and plasticity, which are fully blocked with N-methyl-D-aspartate (NMDA) receptor antagonists, may underlie epilepsy induction and seizure-associated memory deficits.
Abegg
Mathias H
MH
Brain Research Institute, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland. mhabegg@access.unizh.ch
Savic
Natasa
N
Ehrengruber
Markus U
MU
McKinney
R Anne
RA
Gähwiler
Beat H
BH
D000818:Animals; D004827:Epilepsy / Q000503:physiopathology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate