Fig. 5.

Sources of cytosolic calcium rise. A, WIN-induced Ca²⁺ signals are from release of intracellular calcium stores in both DRG and F-11 cells. Cells were treated with thapsigargin (150 nM) or 2-APB (100 μM) for 5 min to deplete or block release from intracellular Ca²⁺ stores. The application of TG or 2-APB before WIN abolished the calcium rise. In contrast, the removal of extracellular Ca²⁺ (“′Ca²⁺, 0 nM”) from DPBS did not affect the WIN-induced Ca²⁺ signals. Values are averages from 15 to 20 cells ± S.E.M. B, NMDA-induced Ca²⁺ signals are from extracellular calcium sources. Removal of extracellular Ca²⁺ (Ca²⁺, 0 nM) from DPBS abolished the NMDA-induced Ca²⁺ rise, whereas pretreatment with thapsigargin did not reduce the Ca²⁺ signals. *, p < 0.05 compared to control. The dotted line indicates the baseline calcium level.