Figure 4.

KCC2 controls spine volume and efficacy of glutamatergic AMPAR-mediated synaptic transmission in mature neurons. KCC2 suppression in mature neurons indicates that KCC2 is not required for spine maintenance, while it contributes to both spine head volume regulation and the efficacy of excitatory synapses by physically constraining AMPAR GluA1 subunit in spine head, likely through its interaction with submembrane actin cytoskeleton [adapted from Gauvain et al. (2011)]. A loss of KCC2 clusters induced by sustained excitatory synaptic activity or under pathological conditions may induce a rapid homeostatic adjustment of the efficacy of AMPAR mediated synaptic transmission as well as a reduction in the efficacy of GABA_AR-dependent synaptic transmission.