Fig. 1.

A schematic diagram summarizing the functions of cofilin1 in dendritic spines. Under basal conditions (b), before induction of either LTP or LTD, cofilin1 is present in dendritic spines [23]. Electron microscopy revealed an enrichment of cofiin1 in the spine head periphery [19], are sub-spinous region with a more dynamic actin network compared to the spine head core or the spine neck [27]. Under non-stimulated conditions, cofilin1 controls lateral diffusion of AMPAR, presumably via an actin-dependent mechanism [21]. Upon LTP induction (c), more cofilin1 moves into dendritic spines and this translocation is required for actin polymerization and spine enlargement [23]. Moreover, cofilin1-dependent actin dynamics control the synaptic accumulation of AMPAR during LTP [22]. Thereafter, during consolidation of structural changes (d), cofilin1 becomes phosphorylated (inactivated) and accumulates at the center to base sub-region of the spine head [22, 23]. a Upon induction of LTD, cofilin1 moves into dendritic spines [35], and cofilin1-dependent disassembly of F-actin mediates spine shrinkage [4]. Arrows indicate lateral diffusion of AMPAR in the extra-synaptic membrane