Excitatory amino acid receptors appear to mediate paroxysmal depolarizing shifts in rat neocortical neurons in vitro.
This study was designed to assess some of the contributions of excitatory amino acids to locally evoked responses in neurons in slices from frontal motor cortex in Sprague-Dawley rats. Intracellular recordings were obtained from 54 cortical neurons. Paroxysmal depolarization shifts (PDS) were evoked by local single pulse stimulation in cortex or in a small number of cases (n = 2) occurred spontaneously. These potentials could be abolished by application of kynurenic acid, a broad spectrum excitatory amino acid receptor antagonist. They were enhanced in Mg(2+)-free medium and could then be antagonized by application of D,L-2-amino-5-phosphonovalerate (AP5), a selective blocker of the N-methyl-D-aspartate (NMDA) receptors.
Mental Retardation Center, University of California, Los Angeles 90024.
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Uchida
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000596:Amino Acids; D000818:Animals; D005625:Frontal Lobe / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007736:Kynurenic Acid; D008274:Magnesium / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009044:Motor Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors
D000596:Amino Acids; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D016194:Receptors, N-Methyl-D-Aspartate; D015763:2-Amino-5-phosphonovalerate; D007736:Kynurenic Acid; D008274:Magnesium