Feudel Ulrike, Neiman Alexander, Pei Xing, Wojtenek Winfried, Braun Hans, Huber Martin, Moss Frank
Department of Physics, University of Potsdam, Potsdam 14415, Germany.
Chaos. 2000 Mar;10(1):231-239. doi: 10.1063/1.166488.
We study global bifurcations of the chaotic attractor in a modified Hodgkin-Huxley model of thermally sensitive neurons. The control parameter for this model is the temperature. The chaotic behavior is realized over a wide range of temperatures and is visualized using interspike intervals. We observe an abrupt increase of the interspike intervals in a certain temperature region. We identify this as a homoclinic bifurcation of a saddle-focus fixed point which is embedded in the chaotic attractors. The transition is accompanied by intermittency, which obeys a universal scaling law for the average length of trajectory segments exhibiting only short interspike intervals with the distance from the onset of intermittency. We also present experimental results of interspike interval measurements taken from the crayfish caudal photoreceptor, which qualitatively demonstrate the same bifurcation structure. (c) 2000 American Institute of Physics.
我们研究了热敏神经元的修正霍奇金-赫胥黎模型中混沌吸引子的全局分岔。该模型的控制参数是温度。在很宽的温度范围内都能实现混沌行为，并使用峰峰间期将其可视化。我们观察到在某个温度区域峰峰间期会突然增加。我们将此识别为嵌入在混沌吸引子中的鞍-焦点不动点的同宿分岔。这种转变伴随着间歇性，对于仅表现出短峰峰间期的轨迹段的平均长度，间歇性遵循与距间歇性开始的距离相关的通用标度律。我们还展示了从小龙虾尾感光器获取的峰峰间期测量的实验结果，这些结果定性地证明了相同的分岔结构。（c）2000美国物理学会。
