Figure 1. Endogenous FGF14 regulates Ca²⁺ channel currents in granule cells.

A. Example Ca²⁺ channel current traces (using Ba²⁺ as the charge carrier) recorded from a cerebellar granule cell transfected with GFP-control (black), scrambled control shRNA (gray), or FGF14 shRNA (blue). The currents were evoked by a ramp protocol from a holding potential of −80 mV to 50 mV in 1 sec. B. Summary data from granule cells expressing GFP control (n=17), scrambled control shRNA (n=10), or FGF14 shRNA (n=12). C. Example Ca²⁺ channel current traces recorded from a cerebellar granule cell transfected with GFP-control (black), scrambled control shRNA (gray), or FGF14 shRNA (blue). The currents were evoked by a step protocol from a holding potential of −80 mV to −10 mV in 500 ms. D. Summary data from granule cells expressing GFP control (n=22), scrambled control shRNA (n=11), or FGF14 shRNA (n=10). E. Representative Cd²⁺-sensitive Ba²⁺ currents evoked by a single action potential waveform (APW, top) command recorded from granule cells transfected with GFP control (black), scrambled control shRNA (gray), or FGF14 shRNA (blue). The integrated current (Q) is colored with black, gray, or blue. F. Summary data of the integrated current (Q) normalized to each cell capacitance. Summary results were obtained from granule cells expressing GFP control (n=25), scrambled control shRNA (n=11), or FGF14 shRNA (n=10). **p<0.01 versus Control.