Figure 9. TBS-induced PP → CA1_tuft LTP is blocked by intracellular calcium buffering with a high concentration of BAPTA, but not a low concentration of BAPTA or low or high EGTA.

(A–D) Representative time course of EPSP amplitude before and after TBSx3+Current was delivered (arrows) from cells buffered with 0.5 mM EGTA (A), 0.5 mM BAPTA (B), 10 mM EGTA (C), or 10 mM BAPTA (D). CaCl₂ was added to maintain basal calcium level (∼50 nM; see ‘Materials and methods’). Calcium buffer was included in the intracellular solution. Top, representative traces (single trials) of EPSP before (1) and 25 min after (2) TBSx3+Current was delivered. The scale bar in A applies to all panels. (E) Summary of the LTP experiments with different calcium buffering. EPSP amplitude is normalized to the average EPSP amplitude before LTP induction. Solid lines and shaded areas represent mean and S.E.M., respectively. (F) Potentiation ratio in different experimental conditions (0.5 mM EGTA, n = 8; 0.5 mM BAPTA, n = 5; 10 mM EGTA, n = 5; 10 mM BAPTA, n = 8). ##p < 0.01, #p < 0.05 for the effect of time on EPSP amplitude by one-way repeated measures ANOVA. *p < 0.05 (compared to 10 mM EGTA) by one-way ANOVA with post hoc means comparison using Tukey's test.

DOI: http://dx.doi.org/10.7554/eLife.06414.032