Low-Dimensional Chaos in Large Conductance Ca-Activated K-Channel Gating Kinetics

摘要: The dynamics of single channel gating kinetics is conventionally attributed to stochastic processes generating the open and close states channel. However, recent evidence has accumulated for low-dimensional deterministic in geometric or temporal evolution various biological systems. Representative time series a large conductance Ca-activated K-channel (BK channel), obtained from cell-attached patch-clamp human pituitary cell, were studied by dynamical analysis. Dynamical analysis nonlinear measures nonstationary included geometrical reconstruction recurrence diagrams, point correlation dimension (PD2i), “chaoticity” dynamic Lyapunov exponents, long-range scaling properties. Statistical significance was phase-randomized data sets constructed original addressing null hypothesis that indistinguishable process (linearly correlated noise). diagrams revealed nonstationarities but showed geometrically structure absent surrogate series. dimensions (PD2i) 5.5 2.9 series, statistically different their counterparts (7.6 6.0, respectively), small noninteger numbers suggesting chaos. largest most positive indicative chaotic dynamics. asymptotic exponents > 0.5 < 1.0 both presence scale-invariant power-law correlations (“memory”). results suggest ion exhibit call descriptors gating, reinvestigation other types fractal modeling.