Effects of CGP52432 on evoked excitation. (a) Examples of responses to AP threshold stimulation with 5 Hz train in control (upper) and observational fear (OF) group (lower) before (left, ACSF), and after (right, CGP52432) perfusion with CGP52432. (b) Right: firing probabilities during the entire train (left: data for individual cells) and upon each stimulus in control (upper): nine cells/three mice and OF (lower): eight cells/three mice. (c) Left: examples of EPSPs evoked by AP subthreshold stimulation in control (upper) and OF group (lower) in the same cells before (left, ACSF) and after (right, CGP52432) perfusion with CGP52432. Averages of five sweeps are shown. (d) Left: Amplitudes of the first EPSPs in the train before and after perfusion with CGP52432, lines connect data points representing the same cells. Right: EPSP amplitudes and time integrals normalized to the values of the first EPSP, before and after perfusion with CGP52432; control: 13 cells/3 mice, OF: 13 cells/3 mice. ASCF vs CGP52432: *p<0.05, **p<0.01, and ***p<0.001. Black and gray colors represent control and OF groups, respectively. Error bars represent SEM.