Detrended fluctuation analysis as a statistical method to study ion single channel signal.

The scaling behaviors of ion single channel current signal time series could be analyzed by means of detrended fluctuation analysis. Nevertheless, the statistical analysis of an ionic current signal recorded from voltage dependence K+ single channel is presented. The detrended fluctuation analysis (DFA) exponent alpha is significantly larger than 0.5, as (DFA) exponents were calculated for 4 different pipette potentials in rat dorsal root ganglion neurons. alpha=0.9475+/-0.006 for V=-30 mV; alpha=0.958+/-0.004 for V=-40 mV; alpha=0.966+/-0.005 for V=-50 mV; alpha=0.971+/-0.03 for V=-60 mV. The scaling exponents for different pipette potentials reveal the existence of memory in ion channels, and at the same time, the memory in ion channel depends on the pipette potential. The result of Markovian model data showed that it had different DFA exponent alpha which indicates that long-range correlation effect is present amongst the continued conducting states of the ion channel. Thus a scaling exponent description is found to characterize the fluctuation properties of the non-linear behaviors of ion channel kinetics regardless of whether the channel is in open or closed state.