Here we illustrate novel non-linear properties of voltage gated Na+ channel induced by sustained membrane depolarization. In cell-attached patch clamp recordings of rNav1.2 channels expressed in CHO cells, we found complex non-linear changes in the molecular kinetic properties, including channel dwell times and unitary conductance of single Na+ channels that were dependent on the extent of conditioning membrane depolarization. A “molecular memory” phenomenon arises at longer depolarization characterized by clusters of dwell time events and strong autocorrelation in dwell times. Hidden Markov Modeling (HMM) ... suggested a possible explanation to the memory phenomenon. See paper for more and details.
Model Type: Channel/Receptor
Currents: I Sodium
Model Concept(s): Ion Channel Kinetics; Epilepsy; Markov-type model
Simulation Environment: Yale HMM
Implementer(s): Nayak, Tapan Kumar [tapan at mbu.iisc.ernet.in]
Nayak TK, Sikdar SK. (2007). Time-dependent molecular memory in single voltage-gated sodium channel. The Journal of membrane biology. 219 [PubMed]