[Analysis of electrophysiologic characteristics of the frog atrial trabecular membrane by ionic currents at a fixed...

The membrane of frog auricle trabecula was studied by the method of potential fixation. On the basis of the records of ionic currents zyro-isoclines of approximative differential equations of the 2nd order, describing the membrane studied, were plotted. The mathematical model of this membrane was analysed with the help of qualitative methods of the oscillation theory. The analysis has shown that the following phenomena which have not been observed experimentally should take place in the membrane of frog auricle trabecula: 1. absence of the minimum gradient and accomodation growth of thresholds; 2. absence of anode-disconnecting excitation; 3. coincidence of the current of repeated responses with that of the rheobase; 4. uneven depolarization.