Long-term depression in the hippocampal CA1 region is associated with equal changes in AMPA and NMDA receptor-mediated synaptic potentials.
In the CA1 hippocampal region low-frequency (1-2 Hz) afferent activation leads to a long-term depression of excitatory synaptic potentials that is induced by calcium influx through postsynaptic N-methyl-D-aspartate receptor channels. In the present experiments using 2- to 3-week-old rats, long-term depressions of field excitatory postsynaptic potentials mediated by amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and by N-methyl-D-aspartate receptor channels were examined in parallel, using a perfusion solution containing low concentrations of an AMPA receptor antagonist and of magnesium (0.1 mM). These experiments revealed that long-term depression was associated with equal relative changes in the two components of the field potential, compatible with a presynaptic location of the expression mechanism for the long-term depression.
Department of Physiology, University of Göteborg, Sweden.
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Xiao
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Wigström
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Gustafsson
D000818:Animals; D003864:Depression, Chemical; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D008274:Magnesium / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D018091:Receptors, AMPA / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D008274:Magnesium