[biological_process] actin cytoskeleton organization <sep> cellular response to calcium ion <sep> dendritic spine maintenance <sep> inositol metabolic process <sep> inositol phosphate biosynthetic process <sep> modification of postsynaptic actin cytoskeleton <sep> phosphatidylinositol phosphate biosynthetic process <sep> positive regulation of dendritic spine morphogenesis <sep> regulation of synaptic plasticity <sep> response to calcium ion