Figure 3.
Constitutive and regulated trafficking of AMPARs at synapses. Left. AMPAR oligomers containing GluR1 or GluR4 subunits are added into synapses in an activity-dependent manner (regulated delivery)
during long-term potentiation (LTP). GluR2–GluR3 oligomers are continuously cycling (constitutive pathway) in and out of synapses.
Right. The activity-dependent (regulated) removal of AMPARs from synapses (LTD) is likely to affect all receptor populations.