Figure 6.

NMDAR activation and interaction of NMDARs with CaMKII are required for LTP-induced new spine stabilization. A, New spines (solid yellow arrowheads at 0 min) were stimulated in the absence (LTP stim) or presence (LTP stim + CPP) of CPP. Time stamps are in minutes. Scale bar, 1 μm. B, In the presence of CPP, no significant increase in survivorship was observed for stimulated new spines (solid gray bar; 22 spines) over unstimulated new spines (open gray bar; 43 spines; p = 0.4, Barnard's exact test). As expected, in the absence of CPP, survivorship of stimulated new spines (solid red bar; 21 spines) increased as compared to that of unstimulated new spines (open red bar; 56 spines; p < 0.05, Barnard's exact test). C, New spines (solid yellow arrowheads at 0 min) on dendrites from CA1 neurons in hippocampal slice cultures from WT and GluN2B L1298/R1300Q knock-in mice (KI) were stimulated with the uncaging LTP stimulus (LTP stim). Time stamps are in minutes. D, No significant increase in survivorship was observed in GluN2B KI mice for stimulated new spines (solid orange bar; 8 spines) over unstimulated new spines (open orange bar; 30 spines; p = 0.4, Barnard's exact test). As expected, survivorship of stimulated new spines (solid red bar; 6 spines) increased in WT mice as compared to unstimulated new spines (open red bar; 30 spines; p < 0.02).