Figure 9.

Pharmacology of depolarization-evoked calcium transients. A, Image of the dye-filled Purkinje cell that was used for recordings shown in B. The white rectangle indicates the ROI. B, Typical example of a calcium transient (top) evoked by injection of depolarizing currents. The delayed pattern of broad spikes (bottom) is associated with a calcium transient. C, Image of the dye-filled Purkinje cell that was used for recordings shown in D. The ROI is indicated by the white box. D, Calcium transients under control conditions and in the presence of ω-agatoxin IVa (200 nm). E, Depolarization-evoked calcium transients were significantly reduced by ω-agatoxin IVa (200 nm; n = 5), but not by nimodipine (10 μm; n = 6), or mibefradil (10 μm; n = 5). All values were obtained after normalization of baseline responses before bath application of the drugs (illustrated by the control bar on the left, which therefore always has a value of 100%). Two stars indicate statistical significance (p < 0.01). F–H, Depolarization-evoked spike activity under control conditions (F), in the presence of ω-agatoxin IVa (G), and after wash-out (H). These traces were obtained from the same cell, in which the calcium transients shown in D were monitored.