Fig. 3. Enhanced activity-dependent Ca²⁺ levels mediated by L-type VGCCs.

a The majority of VDRNs showed an increased Ca²⁺ ΔF/F in response to L-VGCC agonist Bay K8644, suggesting functional L-VGCC expression. b In the presence of 1,25(OH)₂D, Bay K8644 increased VDRN Ca²⁺ ΔF/F in a manner comparable to Bay K8644 alone (Fig. 1i) and was attenuated by preincubation in L-VGCC antagonist nifedipine (p < 0.0001). Pre-incubation of imaged slices in nifedipine significantly reduced both the proportion of detected VDRN (c p = 0.01) and magnitude of detected Ca²⁺ ΔF/F changes in response to 1,25(OH)₂D (d p < 0.0001). Data = Mean ± SEM (Unpaired two-tailed t test with Welch’s correction, *p < 0.05, ****p < 0.0001)