Figure 1.

CA3-CA1 synapses express increased LTP and decreased LTD after chronic blockade of NMDA receptors during development. (A Lower) Summary graph showing that SP induced saturated LTP in both control (□) and CPP-treated (■) slices. Significantly higher potentiation was observed in CPP-treated slices compared with control slices. In a different set of control (○) and CPP-treated (●) slices, AP induced saturated LTD. The magnitude of depression was significantly higher in control than in CPP-treated slices. Numerical values marked on the right side of the graph, obtained by normalizing the mean value of saturated LTP to the mean value of saturated LTD, show that the dynamic range is equal in the two conditions. (Upper) Representative traces of EPSPs evoked at labeled time points are illustrated. (Insets) Superimposed rising phases of evoked EPSPs at a higher magnification. (B) Cumulative distribution plots of changes in baseline EPSP slope after induction of LTP (Left) and LTD (Right), showing increased LTP and decreased LTD in CPP-treated slices compared with control slices.