Figure 6.
Dependence of NT secretion on intracellular Ca2+ stores and CaMKII. Hippocampal neurons were transfected with BDNF-GFP (BDNF) and monitored for postsynaptic neurotrophin secretion as in Figure 5. A, C, Time course of depolarization-induced (50 mm K+) release of BDNF-GFP. B, D, Average residual BDNF-GFP fluorescence after 300 s depolarization. B, Preincubation with thapsigargine (10 μm; 10 min) or CPA (3 μm, 30 min) to deplete internal Ca2+ stores or with ryanodine (80 μm; 30 min) to block Ca2+-induced Ca2+ release from internal stores significantly inhibited NT secretion (*p < 0.0001). D, Preincubation with 10 μm KN-62 or 10 μm KN-93 to inhibit CaMKII significantly inhibited NT secretion. For KN-62, data from BDNF and NT-3 release were pooled (*p < 0.01). neg. control, Negative control; rel., relative.