C. Time course of the peak AMPAR-mediated synaptic response to Schaffer collateral stimulation before, during, and after the induction of LTD by LFS (300 pulses at 1 Hz), in control (inactive control), GSK3α (blue) and GSK3β (orange) inhibitor, and AR-18-treated neurons (yellow). Drug treatment was for 1 hour before recording at 10 µM for all compounds. Error bars represent SEM. D. Quantification of average synaptic depression from the last 5 minutes of the time course shown in C. Error bars represent SEM and statistical significance was calculated according to the Mann-Whitney U test. 