【作者】 许玉林； 李莉； 杨明浩； 刘志强； 刘红菊； 古华光； 任维；

【Author】 Yulin Xu1,Li Li1,Minghao Yang1,2,Zhiqiang Liu2,Hongjv Liu1,Huaguang Gu1,CA,and Wei Ren1,2 1Institute of Space Medico-Engineering,P.O.Box 5104,Branch 15,Beijing 100094,China 2College of Life Science,Shaanxi Normal University,Xian,Shaanxi 710062,China

【机构】 航天医学工程研究所； 陕西师范大学生命科学院,陕西省西安市陕西师范大学；

【摘要】 确定性神经放电数学模型中存在3种从周期1簇放电到周期2簇放电分岔模式,但与实验不完全类似。在第1种分岔中,随着分岔参数的变化,周期2的ISIs逐渐变化,一个降低而另一个增加;在分岔点附近周期1和周期2簇放电共存。在第2种和第3种分岔,随着分岔参数的变化,周期1和周期2的ISIs基本不变。在第2种分岔,周期1和周期2仍有共存,在第3种中则没有共存。在确定性模型引入模拟环境涨落得噪声,可以模拟实验中得3类分岔。噪声对第一种分岔得分岔结构影响很小。在第2种和第3种分岔,噪声可以诱发新的放电模式。在第2种分岔模式中,新的放电模式为周期1簇放电串和周期2放电串的随机转换,而在第3种分岔,则为周期1簇放电和周期2簇放电的随机转换。在随机模型中仿真出的3种分岔模式均在实验性神经起步点的神经放电实验中得到验证。更多还原

【Abstract】 Three cases of bifurcation from period 1 bursting to period 2 bursting discovered in the experiment on neural pacemakers can be interpreted by the results of the deterministic and stochastic theoretical model.Three cases of bifurcation from period 1 bursting to period 2 bursting can be simulated in the deterministic theoretical model.In Case I bifurcation,the interspike intervals (ISIs) of period 2 bursting change from the ISI of period 1 bursting gradually.One decreases and the other increases.Period 1 bursting and period 2 bursting coexist near the bifurcation point.Near Case II and III bifurcation point,the shorter ISI of period 2 bursting generates suddenly and the ISIs of period 1 bursting and period 2 bursting change little.There exists coexistence of period 1 and period 2 bursting in Case II bifurcation while no coexistence in type III bifurcation.In the stochastic model,noise plays little role in Case I bifurcation,while plays important role in Case II and III bifurcations and can induce new firing patterns lying between period 1 bursting and period 2 bursting.The behavior of the new firing is stochastic transition between string of period 1 burst and string of period 2 burst in case II bifurcation while stochastic transition between period 1 burst and period 2 burst in case III bifurcation.Three cases of bifurcation simulated in the stochastic theoretical model can be discovered in the experiment on neural pacemaker.The dynamics of bifurcation from period 1 bursting to period 2 bursting including the effect of noise near the bifurcation point in real neural firing are identified.更多还原