Presynaptic External Calcium Signaling Involves the Calcium-Sensing Receptor in Neocortical Nerve Terminals
Figure 5
Calindol activation of CaSR expressed in HEK cells occurred with a greater latency than Ca2+ activation of CaSR.
A, application of Ca2+ (5 mM) and Calindol (10 µM) at time zero to CaSR-expressing HEK cells in 1 mM Ca2+ and 0 Mg2+ caused a transient increase in fluorescence (F) relative to basal level (F0) indicating an increase in [Ca2+]i. The black curves denote signal from 12 cells and the red curves indicate the average. There was a 5 minute delay between applications. B, average curves from A have been redrawn on the same time-expanded axis to compare effect latency of Calindol vs. Ca2+. C, histogram of latency of effect for Ca2+ and Calindol. The latency was significantly greater for activation by Calindol (23.7±1.2 s) than by Ca2+ alone (9.0±0.2 s) in the recordings from 22 cells (p<0.001).