[Stochastic synchronization of biological systems by external periodic factors]

Influence of external periodic factors on auto-scillation model of biological processes was studied. It has been shown that the cycle pairs are initiated from the condensation of trajectories: a stable and unstable cycles, whose period is five-fold higher than the period of external influence. When the oscillation amplitude of external influences increases due to a successive doubling of the periods, the stable regime is transformed into stochastic oscillations.