Figure 2.

α7 promotes IP₃R-mediated calcium release at the GC. A) Colocalization of fBgtx and anti-IP₃R Ab staining in the central zone (CZ) of the GC. B) α7-mediated calcium signaling in the GC is abolished in the presence of 1 μM thapsigargin (Thaps) or Xest C, but not 30 μM Ry. DMSO was used as a vehicle control. C) α7-mediated calcium elevation in the GC and proximal neurite. Live imaging of GCaMP5G and ER-Tracker Red in cells treated with 10 mM choline (beginning at 0.5 s). Images: WT (left panels); preincubated with Xest C (middle panels); transfected with D44A (right panels). Boxed areas in top panels represent ROIs of the GCaMP5G signal, shown as a heat map at the GC (0 μm) and 10–40 μm into the neurite. ER is outlined in black. Bottom panels: ER-Tracker labeling in the neurite. D) Average values from C showing changes in calcium (left panels) and a correlation of peak calcium rises relative to the detection of the ER-Tracker signal in the GC and adjoining neurite (right panels). Error bars = means ± sem. ***P < 0.001; Student's t test.