Chaotic bursting as chaotic itinerancy in coupled neural oscillators.
We show that chaotic bursting activity observed in coupled neural oscillators is a kind of chaotic itinerancy. In neuronal systems with phase deformation along the trajectory, diffusive coupling induces a dephasing effect. Because of this effect, an antiphase synchronized solution is stable for weak coupling, while an in-phase solution is stable for very strong coupling. For intermediate coupling, a chaotic bursting activity is generated. It is a mixture of three different states: an antiphase firing state, an in-phase firing state, and a nonfiring resting state. As we construct numerically the deformed torus manifold underlying the chaotic bursting state, it is shown that the three unstable states are connected to give rise to a global chaotic itinerancy structure. Thus we claim that chaotic itinerancy provides an alternative route to chaos via torus breakdown.
Han
Seung Kee
SK
Department of Physics and BSRC, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea.
Postnov
D E
DE
D000818:Animals; D002490:Central Nervous System / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D008962:Models, Theoretical; D009420:Nervous System; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D017711:Nonlinear Dynamics; D009991:Oscillometry; D013997:Time Factors