At individual spines, the maximal uEPSC positively correlates with the relative bound amount of GFP-CaMKIIα. A, An overlay of green and red fluorescence from a dendrite expressing GFP-CaMKIIα (green) and mRFP (red). B, Calculated locations of relative bound GFP-CaMKIIα amount. C, uEPSCs maps for spines of the same dendrite. D–G, Plots showing dependence of maximal postsynaptic uEPSC on the amount of bound CaMKII and dependence of CaMKII bound amount, bound fraction and uEPSC on spine volume for the spines shown in A. Scale bar, 1 μm.