FIG. 4.

The time course of the DSI-evoked enhancement of C2 spike-evoked Ca²⁺ signals matched that of the DSI-evoked synaptic enhancement. A: calcium signals expressed as percentage pretest for control and at varying times with respect to a DSI spike train (10 Hz, 5 s). *, statistically significant differences from the control with a Friedman repeated-measures ANOVA on ranks [performed using normalized data, with the factor being the time between the end of the DSI spike train and the C2 spikes (−3, 2, 5, 10, 20 s) with post hoc pair-wise comparisons (Student-Newman-Keuls], n = 5. As a control, C2 stimulated twice with no DSI stimulation. B: the amplitude of C2-evoked EPSPs expressed as percentage of pretest for control and at varying times with respect to a DSI spike train (10Hz, 5s). *, statistically significant differences from the control using the same statistical methods as in A (n = 6).