Period doubling bifurcation in a train of spontaneous activity

Introduction: It has been shown that fibrillations (FIBs) and positive sharp waves (PSWs) occur during spontaneous oscillations of the membrane potential when the threshold is reached. According to the models of excitable membranes these oscillations should be nonlinear. We wondered whether the nonlinearity of the underlying process could also be demonstrated indirectly in the pattern of spontaneous discharges that can be recorded much easier extracellularly in routine electromyography. A simple example of nonlinear behaviour is a period doubling bifurcation in a periodic system. Methods: In our clinical neuroph…