1. Depolarization-induced postsynaptic NT secretion depends on Ca2+ influx.
Depolarization-induced postsynaptic NT secretion depends on Ca2+ influx. Hippocampal neurons were transfected with GFP-tagged BDNF and NT-3, and depolarization-induced (50 mm K+, 300 s; postsynaptic receptors blocked with 10 μm DNQX, 50 μm d,l-APV, and 50 μm gabazine) postsynaptic secretion of NTs was measured as the decrease in intracellular fluorescence intensity. A , Change in BDNF-GFP secretion after consecutive depolarizations of the same cell in the absence/presence of extracellular Ca2+ (2 mm). B , Time course of secretion of BDNF-GFP and NT-3-GFP. Preincubation with the L-type Ca2+ channel antagonist nifedipine (50 μm; 10 min) significantly inhibited (p < , at t = 300 s) secretion of both NTs. C , Residual intracellular fluorescence after 300 s stimulation for conditions as indicated. **p < compared with negative control (neg. con). Note the strong dependence of BDNF and NT-3 secretion on the activity of L-type VGCCs. Error bars represent SEM.
Richard Kolarow et al. J. Neurosci. 2007;27:
©2007 by Society for Neuroscience