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Table 1 Parameters of the model. Values used in the fits illustrated in Figs 2 and 3 are compared with the generic values for macaque reported in [3].

From: The photocurrent response of human cones is fast and monophasic

Parameter Description Generic macaque cone [3] Human cone (Fig. 2) Ground squirrel (Fig. 3) Units
τR Time constant of R* inactivation 3.4 3.4 3.0 ms
τE Time constant of E* inactivation 8.7 9.6 13 ms
τD Time constant of cGMP hydrolysis in darkness 360 360 60 ms
k β Coupling gain from light intensity to rate of hydrolysis of cGMP 1.6·10-4 10-4   (ms)-1 td-1
     2.1·10-7 (ms)-1 (isom/s)-1
n X Apparent Hill coefficient of CNG channel activation 1 1 1.7 -
τCa Time constant of Ca2+ extrusion 3 3 4.8 ms
n cyc Hill coefficient of GC activation 4 4 3.2 -
a cyc Scaling constant of GC activation 9·10-2 9·10-2 3.7·10-2 -
τm Outer segment capacitive time constant < 4 2.3 2.3 ms
t delay Delay time < 3 1.3 2.2 ms