Figure 2.

Dopamine‐induced astroglial Ca²⁺ elevations depend on intracellular Ca²⁺ storage and removal but not on IP₃ diffusion buffering. A: Average time course (mean ± SEM, n = 9) of Ca²⁺ ‐dependent fluorescence (ΔF/F, Fluo‐4) in GJC astroglia during the application of cyclopiazonic acid (CPA) (30 µM) and, subsequently, DA (100 µM), as indicated. B: Average time course (mean ± SEM, n = 3) of Ca²⁺ ‐dependent fluorescence (ΔF/F, Fluo‐4) in bulk‐loaded astroglia during the application of DA (100 µM, 5 min), then thapsigargin (Th, 5 µM), and another DA application, as indicated. C: Characteristic Ca²⁺ responses (Fluo4 fluorescence) to DA application (100 μM, grey bar) in bulk‐loaded hippocampal astrocytes from wild‐type mice (WT, top) and IP₃‐sponge mice (bottom). D: Average time course (mean ± SEM) of ΔF/F Ca²⁺ responses to DA (as in C) from wild‐type mice (hollow circles, n = 18) and IP₃‐sponge mice (grey circles, n = 16). [Color figure can be viewed at wileyonlinelibrary.com]