Figure 5.
Cdk5 regulates the CaV channel currents in DRG neurons. A, Immunoprecipitation of CaV3.2 channels and Cdk5 in the DRG. Top, Western blot (WB) of the immunoprecipitation (IP) of the CaV3.2 channels using Cdk5 or control (Ig0) antibodies. Bottom, Reciprocal immunoprecipitation experiment for Cdk5. The results are representative of three independent determinations. B, Superimposed current traces recorded in DRG neurons in the absence and the presence of the Cdk5 inhibitor olomoucine. Currents were evoked by applying voltage steps to 0 mV from a Vh of −80 mV. C, Average normalized Idensity–V curves in DRG neurons obtained in the presence or absence of olomoucine as in B (n = 13 recorded cells). For these electrophysiological recordings, only small cells were used (Scroggs and Fox, 1992). The Cm values varied from 22.2 to 23.4 pF, and the diameter of the cells ranged from 15.6 to 17.5 μm in control and olomoucine-treated cells, respectively. D, Comparison of the isolated LVA (CaV3) channel current component in the presence or absence of olomoucine. The asterisk denotes a significant difference from the control condition (Table 1).