Keplinger Keegan, Wackerbauer Renate
Department of Physics, University of Alaska, Fairbanks, Alaska 99775-5920, USA.
Chaos. 2014 Mar;24(1):013126. doi: 10.1063/1.4866974.
Transient behavior is thought to play an integral role in brain functionality. Numerical simulations of the firing activity of diffusively coupled, excitable Morris-Lecar neurons reveal transient spatiotemporal chaos in the parameter regime below the saddle-node on invariant circle bifurcation point. The neighborhood of the chaotic saddle is reached through perturbations of the rest state, in which few initially active neurons at an effective spatial distance can initiate spatiotemporal chaos. The system escapes from the neighborhood of the chaotic saddle to either the rest state or to a state of pulse propagation. The lifetime of the chaotic transients is manipulated in a statistical sense through a singular application of a synchronous perturbation to a group of neurons.
瞬态行为被认为在大脑功能中起着不可或缺的作用。对扩散耦合的可兴奋Morris-Lecar神经元的放电活动进行数值模拟，发现在不变圆分岔点的鞍结下方的参数区域中存在瞬态时空混沌。通过对静止状态的扰动可到达混沌鞍点的邻域，在该邻域中，在有效空间距离处少数最初活跃的神经元可引发时空混沌。系统从混沌鞍点的邻域逃逸到静止状态或脉冲传播状态。通过对一组神经元进行奇异的同步扰动，从统计学意义上控制混沌瞬态的寿命。
