A, simulated time courses of the amount of non-phosphorylated AMPARs before and after an increase in [Ca2+]i and glutamate under reduced CaMKII. The amount of cAMP or cGMP was doubled. B, relation between the simulated AMPAR amount (at 30 min) and the altered amount of cGMP/cAMP. C, time courses of glutamate response amplitudes before and after the LTD conditioning stimuli in the absence or presence of AIPII, and 8-pCPT-cGMP or Sp-cAMP. n = 5 for each. Data without (control) and with AIPII (AIPII, same as those in Fig. 2B) are presented for comparison. D, simulated time courses of amount of non-phosphorylated AMPARs under reduced CaMKII. The amount of PKG or PKA was reduced to 40% in addition to PDE1 reduction to 40%. E, relation between the simulated AMPAR amount (at 30 min) and the altered amount of PKG/PKA. F, time courses of glutamate response amplitudes before and after the LTD conditioning stimuli in the absence or presence of AIPII, 8-MM-IBMX and KT5823 or KT5720. n = 5 for each. Data with AIPII alone or that with AIPII and 8-MM-IBMX (same as those in Figs 2B and 5E) are presented for comparison.