Figure 2.

I_BDNF activation requires PLC activity, functional IP₃ receptors, full intracellular stores, Ca²⁺ influx, and intracellular Ca²⁺ elevations. A, Bath application of the PLC inhibitor U73122 completely blocked I_BDNF. B, Intracellular application of xestospongin-C (Xes-C; 1 μm), a specific inhibitor of IP₃Rs, prevents I_BDNF. C, Depletion of intracellular stores with the SERCA pump inhibitor thapsigargin (1 μm) also abolishes I_BDNF. D, Consistent with a requirement of Ca²⁺ signaling, I_BDNF was also inhibited by loading neurons with the fast Ca²⁺ chelator BAPTA (20 mm). E, Activation of I_BDNF also requires extracellular Ca²⁺. F, Average amplitude of I_BDNF in the above experimental conditions (*p < 0.0001 vs BDNF application in TTX).