Neurons from mES cells were pretreated for 15 min with different Ca2+ channel inhibitors: nifedipine (Nif, 10 µM), ω-conotoxin GVIA (CgTx, 1 µM), ω-agatoxin IVA (AgTx, 200 nM) before exposed to 10 nM E2. Alternatively, the cells were treated directly with the above inhibitors, E2 and membrane-impermeable E2-BSA (10 nM). Changes after drug treatment (gray bars) in the frequency of [Ca2+]i oscillations (A) and amplitudes of [Ca2+]i peaks (B) compared to basal levels (black bars, normalized to 1). The number of cells for Nif, Nif+E2, AgTx, AgTx+E2, CgTx, CgTx+E2, E2-BSA, E2 and Ctrl are 233, 213, 163, 170, 165, 156, 139, 113 and 99, respectively, from 5, 4, 3, 3, 3, 3, 3, 3, and 2 independent experiments. ** p<0.01, * p<0.05 in comparison to non-treatment control.