Amplitude fluctuations of dual-component EPSCs in hippocampal pyramidal cells: implications for long-term potentiation.
Quantal analysis has provided evidence for a presynaptic contribution to long-term potentiation in hippocampal CA1 cells. This however leaves unexplained the observation that long-term potentiation has little or no effect on the NMDA receptor-mediated component of the synaptic signal. Here, I report that, in baseline conditions, the coefficient of variation of the AMPA/kainate receptor-mediated signal (CVA/K) is consistently larger than that of the NMDA component (CVNMDA), a result which can be explained if AMPA/kainate receptors are absent or nonfunctional at a proportion of synapses. Long-term potentiation is associated with a reduction in CVA/K, but no change in either the average amplitude of the NMDA component or CVNMDA. This is consistent with the proposal that long-term potentiation induction uncovers clusters of latent AMPA/kainate receptors, with no change in transmitter release.
Kullmann
D M
DM
Department of Clinical Neurology, Institute of Neurology, London, England.
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D008012:Lidocaine / Q000031:analogs & derivatives / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D018091:Receptors, AMPA / Q000502:physiology; D018092:Kainic Acid Receptors / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology
D015763:2-Amino-5-phosphonovalerate; D000779:Anesthetics, Local; D008012:Lidocaine; D011810:Quinoxalines; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate; C012647:QX-314; C056723:FG 9041