TY - JOUR T1 - Differential Trafficking of AMPA and NMDA Receptors during Long-Term Potentiation in Awake Adult Animals JF - The Journal of Neuroscience JO - J. Neurosci. SP - 14171 LP - 14178 DO - 10.1523/JNEUROSCI.2348-07.2007 VL - 27 IS - 51 AU - Joanna M. Williams AU - Diane Guévremont AU - Sara E. Mason-Parker AU - Carthika Luxmanan AU - Warren P. Tate AU - Wickliffe C. Abraham Y1 - 2007/12/19 UR - http://www.jneurosci.org/content/27/51/14171.abstract N2 - Despite a wealth of evidence in vitro that AMPA receptors are inserted into the postsynaptic membrane during long-term potentiation (LTP), it remains unclear whether this occurs in vivo at physiological concentrations of receptors. To address the issue of whether native AMPA or NMDA receptors undergo such trafficking during LTP in the adult brain, we examined the synaptic and surface expression of glutamate receptor subunits during the early induction phase of LTP in the dentate gyrus of awake adult rats. Induction of LTP was accompanied by a rapid NMDA receptor-dependent increase in surface expression of glutamate receptor 1–3 (GluR1–3) subunits. However, in the postsynaptic density fraction only GluR1 accumulated. GluR2/3-containing AMPA receptors, in contrast, were targeted exclusively to extrasynaptic sites in a protein synthesis-dependent manner. NMDA receptor subunits exhibited a delayed accumulation, both at the membrane surface and in postsynaptic densities, that was dependent on protein synthesis. These data suggest that trafficking of native GluR1-containing AMPA receptors to synapses is important for early-phase LTP in awake adult animals, and that this increase is followed homeostatically by a protein synthesis-dependent trafficking of NMDA receptors. ER -