A–C. FRAP of neurons expressing GFP, GFP-SAP102ΔSH3GK or GFP-SAP102 over a 30-second period. The arrows indicate the spines of interest. Pictures were captured before (Pre) and at 0, 3, 9, and 30 seconds after photobleaching. Scale bar, 5 μm. D. FRAP curves of spines expressing GFP-SAP102ΔSH3GK or GFP-SAP102 over a 30-second period. N = 4 neurons, WT = wild type. E. Half recovery time (τ1/2) of GFP, GFP-SAP102ΔSH3GK, GFP-SAP102, GFP-SAP102PDZ1FH, GFP-SAP102PDZ2FH and GFP-SAP102PDZ3FH. The half recovery time of GFP-SAP102ΔSH3GK is close to that of GFP, but significantly smaller than that of GFP-SAP102, GFP-SAP102PDZ1FH, GFP-SAP102PDZ2FH and GFP-SAP102PDZ3FH. N = 4, 4, 8 neurons, **p<0.01.