Table 2.

Best-fitting parameters describing the voltage-dependence of calcium current.

	Gmax (nS/nF)	V1/2 (mV)	Vr (mV)	z
WT (n = 29)	90 ± 8	4.7 ± 2.5	62 ±3.1	3.9 ± 0.6
DKO	132 ± 12	3.8 ± 1.9	64 ±4.4	4.0 ± 0.8
(n = 29)	(P = 0.005)	(P = 0.775)	(P = 0.712)	(P = 0.921)

Data points were fitted to the following equation: ICa = Gmax (V − Vm)/{1 + exp[zF(V_1/2 − V)/RT]}, where Gmax is the maximum conductance, V is the membrane potential, Vr is the reversal potential, V_1/2 is the half-activation potential, z is the effective valence, F is the Faraday constant, R is the gas constant and T is the absolute temperature (296 K) as described in ref. 43. The number of FDB fibres from three to four mice is between parentheses. Results are expressed as the mean ± s.e.m. Statistical significance was assessed using Student’s t-test. The α-level was set at P= 0.05.