Table 2.

Model mechanisms

Na+ channel
iNa = ḡNam3h (V-ENa), ENa = 74 mV	, τh = 1/(αh + βh)
	h∞ = 1/(1+e(V+60)/4)
αm = -0.08(V+76)/(e-(V+76)/3.5 - 1)	αh = 0.053(V + 62.4)/[1 - e- (V + 62.4)/8]
βm = 0.65(V + 34)/[e(V + 34)/4 - 1]	βh = - 0.004(V + 90)/[1 - e(V + 90)/5.6]
Delayed rectifier K+ channel
iK = ḡKn4(V - EK), EK = - 105 mV	αn = -0.022 (V + 20)/[e-(V + 20)/12 - 1]
	βn = 0.0048 (V + 8)/[e(V + 8)/19 - 1]
High-threshold Ca2+ channel	βm = 0.1 e-V/20
	αh = 0.000168 e-V/36.76
	βh = 1/[1 + e(-V + 56.94)/18.11]
αm = 0.25 (-V + 35)/[e(-V + 35)/10 - 1]	[Ca2+]0 = 2 mm, [Ca2+]i (rest) = 50 nm
Ca-Orange (B) and endogenous buffer (S)
	mm-1 msec-1, μm
	BT = 150 μm, mm-1 msec-1
[CaB] + [B] = BT, [CaS] + [S] = ST	μm, ST = 1.4 mm, F = 96,485 C mol-1
	d(x) = d0e-x/λT,

Model equations describing intrinsic membrane conductances, calcium buffers, and fluorescence. V, Transmembrane voltage; [Ca²⁺]_i, free calcium ion concentration; [B] and [CaB], concentrations of free and calcium-bound forms of Calcium Orange; [S] and [CaS], concentrations of free and calcium-bound forms of endogenous buffer.