(A) Example traces of IIP3 evoked by different concentrations of IP3 (2000, 6000, 16000, 48000, and 140000 µM·µJ) in control and defeated rats. (B) Averaged IP3 concentration-response curves from control and defeated rats. IIP3 amplitudes were normalized to the maximal value (estimated from fit to a logistic equation) in each cell. Recordings were made with normal internal solution or with PKI (control: 12 cells from 8 rats, defeat: 12 cells from 7 rats, control + PKI: 15 cells from 9 rats, defeat + PKI: 14 cells from 8 rats; treatment (defeat/PKI): F3,196 = 4.88, p<0.01; IP3 concentration: F4,196 = 1214, p<0.001; treatment × IP3 concentration: F12,196 = 4.42, p<0.001; mixed two-way ANOVA). ***p<0.001 vs. control (Bonferroni post hoc test). Lines represent logistic fit to the averaged data in each group. (C) Summary bar graph depicting the average EC50 values (EC50 determined in each cell) in the 4 groups shown in (B) (defeat: F1,49 = 5.11, p<0.05; PKI: F1,49 = 5.11, p<0.05; two-way ANOVA). *p<0.05 (Bonferroni post hoc test). (D) The maximal IIP3 amplitude was not affected by social defeat experience or PKI during recording.