Kinetics of
bright-state formation during the write pulse for (a,b)
Arch(D95H) and (c,d) Arch(D95Q). Voltage was held at either +100 or
−100 mV during the write interval and at −100 mV during
the dark and read intervals. The length of the write flash, twrite, was varied, keeping its end coincident
with the step in voltage from +100 mV to −100 mV. Representative
fluorescence traces are shown for (a) Arch(D95H) and (c) Arch(D95Q).
(b,d) Plot of memory effect, ΔM, as a function
of twrite. In Arch(D95H) the rise in memory
was fit by a double exponential with τfast = 0.14
ms (57%) and τslow = 12 ms (43%); a write flash with twrite = 1 ms was sufficient to elicit more than
half of the maximal response. (d) The dependence of ΔM on twrite in Arch(D95Q) was
dominated by a slow component. A fit to a double exponential yielded
τfast = 5 ms (8%) and τslow = 180
ms (92%).