Abstract
Recordings of the electric conductivity of a single ionic channel
usually exhibit two levels of conductance: a zero and a finite level.
The channel may, however, be in a few states which have the same
conductivity level, and the distribution of dwell time durations
at this conductivity level is thus not monoexponential. It is shown
that the joint probability p(tc,to) of the occurrence of a time interval
tc during which the channel is not conducting, immediately followed
by a time interval to during which the channel is conducting may
or may not be equal to the joint probability pr(tc,to) of the occurrence
of a non-conducting interval tc preceded by a conducting interval
to. If the interconversions between the various states in which the
channel can exist obey detailed balance, i.e., if the channel behaves
like a system at thermodynamic equilibrium, then p(tc,to) = pr(tc,to).
This should help to reveal whether irreversible processes, like metabolic
reactions or flows of substances across the membrane, are coupled
to the gating process of the ionic channels.
- 2443766
- biological,
- channels,
- computer
- conductivity,
- electric
- graphics,
- ion
- models,
- probabili,
- probability,
- statistics,
- thermodynamics,
- ty,
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