Astrocytes are the most abundant cells in the central nervous system. These glial cells play crucial roles in maintaining ionic homeostasis and providing structural and metabolic support to neurons, functions that heavily depend on the expression and activity of various ion channels. Traditionally, ion channel gating has been described as a stochastic process; however, experimental evidence suggests that this view may be incomplete, as it fails to account for correlations in single-channel current fluctuations, as revealed by analyses of dwell times and pore fluctuations. In this study, we investigate the structure of high-frequency fluctuations in single-channel currents, typically regarded as noise, by analyzing pore fluctuations at different holding potentials in primary astrocyte cultures from neonatal Wistar rats. Using detrended fluctuation analysis (DFA), we examined fluctuations in the pre-conducting, conducting, and post-conducting states, ensuring reliability by employing an equal number of samples for each case. Our results show that, for all holding potentials evaluated, the scaling exponent in the conducting state exceeded 0.5, indicating long-range correlations in pore fluctuations during this state. In contrast, scaling exponents in the pre- and post-conducting states were predominantly close to 0.5, suggesting random behavior in non-conducting states. These findings imply that pore fluctuations may exhibit correlations preferentially during the conducting state, revealing a more complex dynamic than previously assumed.
Pimentel-Granados et al. (Sun,) studied this question.