Reply to Meredith and Groen: Role of AMPA and NMDA Receptors and Back-Propagating Action Potentials in Spike Timing-Dependent Plasticity

Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avenida Doctor Arce 37, 28002 Madrid, Spain. .
Journal of Neurophysiology (Impact Factor: 2.89). 04/2010; 103(4):2314. DOI: 10.1152/jn.00170.2010
Source: PubMed
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    ABSTRACT: Spike timing-dependent long-term potentiation (t-LTP) is the embodiment of Donald Hebb's postulated rule for associative memory formation. Pre- and postsynaptic action potentials need to be precisely correlated in time to induce this form of synaptic plasticity. NMDA receptors have been proposed to detect correlated activity and to trigger synaptic plasticity. However, the slow kinetic of NMDA receptor currents is at odds with the millisecond precision of coincidence detection. Here we show that AMPA receptors are responsible for the extremely narrow time window for t-LTP induction. Furthermore, we visualized synergistic interactions between AMPA and NMDA receptors and back-propagating action potentials on the level of individual spines. Supralinear calcium signals were observed for spike timings that induced t-LTP and were most pronounced in spines well isolated from the dendrite. We conclude that AMPA receptors gate the induction of associative synaptic plasticity by regulating the temporal precision of coincidence detection.
    Full-text · Article · Sep 2010 · Proceedings of the National Academy of Sciences