Fig. 1.

Depression of eIPSCs in interneurons by Ca²⁺ uncaging in astrocytes. (A) Images from an astrocyte before, during and after stimulation with a train of twelve UV laser pulses (0.1 Hz) to uncage NP-EGTA. Scale bar, 10 μm. (B) Upper: Ca²⁺ uncaging produces a stepwise increase in ΔF/F₀ of the astrocyte in (A) and a reversible decrease in the mean amplitude of eIPSCs (averaged from 24–36 traces) in an interneuron (middle). The amplitudes of eIPSCs over the course of the experiment (lower). (C) Normalized changes in the amplitude of eIPSCs by uncaging. Responder shows the average of nine cells that responded to uncaging by decreasing the amplitude of eIPSCs. Non-Responder shows the average of eight cells that did not respond to uncaging. Total shows the average of all 17 cells. Preloading the slices with BAPTA-AM (10 μM), a calcium chelator, prevents the depression of eIPSCs by uncaging (n = 8). No NP-EGTA indicates slices loaded with fluo-4 alone (n = 9). *P < 0.01 compared with control, BAPTA AM and no NP-EGTA groups by ANOVA with Dunnett's test.