Sustained intracellular Ca2+ elevation induced by a brief BDNF application in rat visual cortex neurons.

A 1-2 min application of brain-derived neurotrophic factor (BDNF; 20 ng/ml) induced sustained elevation of intracellular Ca2+ lasting > 90 min, using the fura-2 imaging of intracellular Ca2+ mobilization, in visual cortical pyramidal neurons isolated from rats. BDNF increased intracellular Ca2+ through the PLC-gamma phosphorylation after the TrkB receptor tyrosine kinase activation. Either K252a or U73122 suppressed intracellular Ca2+ in the absence of BDNF. We suggest that sustained activation of Trk B receptor tyrosine kinase and PLC-gamma occurs after a brief BDNF application and contributes to the short-term maintenance (< 30 min) of the sustained intracellular Ca2+ elevation.