Fig. 7.

Ca²⁺ transients are specifically elevated in distal dendrites of Kv3.3 KO PCs. A and B: resting fluorescence images of wild-type and Kv3.3 KO PCs, with regions of interest (ROIs) demarcated corresponding to proximal (■) and distal () dendritic regions. Scale bar in B is 50 μm. C and D: Ca²⁺ signals averaged within each ROI vs. time for 5 successive climbing fiber stimulations at 1 Hz. Signals in both ROIs peaked simultaneously; however, for purpose of presentation, distal ROI signals are temporally offset slightly in these plots. In the wild-type example, the peak proximal and distal dendritic fluorescence changes are 6.2 ± 1 and 4.1 ± 0.5%, respectively; for the Kv3.3 KO example, 4.9 ± 0.4 and 5.8 ± 0.6%. E: peak ΔF/F signals were determined for each cell and compared between wild-type (n = 4) and Kv3.3 KO (n = 6) PCs. There was no statistically significant difference between amplitudes of proximal signals; however, distal dendritic signals and distal relative to proximal signals within individual trials were significantly larger for Kv3.3 KO PCs (*, P < 0.05). Errors bars are SD.