Figure 3
From: Dynamin-dependent NMDAR endocytosis during LTD and its dependence on synaptic state
Prevention of dynamin-dependent endocytosis of NMDARs by injection of GST-amphiSH3 (100 μg/ml) into the postsynaptic cell significantly attenuates LFS-induced NMDAR down-regulation. The fusion protein was present in the postsynaptic internal solution for the duration of the experiment. Following the attainment of an active synaptic connection (characterized by the appearance of an AMPAR-mediated current at resting membrane potentials), NMDAR-mediated EPSCs were isolated by bath application of NBQX (10 μM) and depolarization to +40 mV. Baseline NMDAR EPSC amplitudes were measured for 10 minutes and then the synaptic pair was subjected to LFS (600 presynaptic action potentials at 1 Hz combined with slight postsynaptic depolarization; [6]). NMDAR EPSC amplitudes were subsequently measured for 30 minutes following LFS. Inset shows ten consecutive postsynaptic traces collected at +40 mV in NBQX, with an exemplar presynaptic action potential, before (1) and 10 minutes after (2) LFS. Closed symbols: GST-amphiSH3 (n = 10 pairs), open symbols: GST-amphiSH3m (n = 6 pairs) protein.