NMDA receptor dependent paroxysmal discharges in the dentate gyrus.
The N-methyl-D-aspartic acid subclass of glutamate receptors is thought to be involved in events that depend on repetitive activation of neurons. The present study shows that repetitive stimulation of CA3 can produce epileptiform discharges in the contralateral dentate gyrus. This distinctive paroxysmal response was blocked by the NMDA antagonists, ketamine and MK-801. The MK-801 blockade required previous activation of the dentate gyrus in the presence of the drug, thus demonstrating, in vivo, a use-dependent effect. These studies show that repetitive, low intensity stimulation of hippocampal circuits can produce NMDA-mediated epileptiform discharges in the dentate gyrus.
Stringer
J L
JL
University of Virginia School of Medicine, Department of Neurology, Charlottesville 22908.
Lothman
E W
EW
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003986:Dibenzocycloheptenes / Q000494:pharmacology*; D016291:Dizocilpine Maleate; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D007649:Ketamine / Q000494:pharmacology*; D007696:Kindling, Neurologic / Q000187:drug effects*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*
D003986:Dibenzocycloheptenes; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D007649:Ketamine; D016291:Dizocilpine Maleate