Figure 4.

Cycling of Ca²⁺ in CPCs in response to electrical stimulation is dependent on the LTCC, IP₃R, and external Ca²⁺. (a) Representative Ca²⁺ oscillations recorded from fluo-4/AM-loaded CPCs at 0.5 Hz electrical stimulation in 2 mM Ca²⁺ Tyrode's solution, pretreated with nifedipine or 2-APB to inhibit the LTCC or IP₃R, respectively, or in 0 Ca²⁺ Tyrode's solution. Traces have been aligned in time based on when electrical stimulation was applied for comparison. Arrow indicates the start of stimulation. (b) Summary bar graph of Ca²⁺ oscillation amplitudes under the various recording conditions in (a). Data represent mean ± SD. ^∗ p < 0.05; Student's t-test. n = 16 cells from 4 different pools of cells for all points.