报告题目:Large-scale Brain Dynamical Mechanisms for Absence Seizures
报 告 人:杨冬平 博士 (悉尼大学)
报告时间:2018年12月27日 (星期四),下午3:00
报告地点:欧亿6蓝狮注册五层会议室(致知楼3514)
报告摘要:
Absence epilepsy is characterized by a sudden paroxysmal loss of consciousness accompanied by oscillatory activity propagating over many brain areas. A physiologically based corticothalamic model of large-scale brain activity is used to analyze critical dynamics of transitions from normal arousal states to epileptic seizures, which correspond to Hopf bifurcations. This relates an abstract normal form quantitatively to the main underlying physiologies that includes neural dynamics, axonal propagation, and time delays. Thus, a bridge is constructed that enables normal forms to be used to interpret quantitative data. This model is further investigated with focal spatial heterogeneity, numerically and analytically. An emergent spatiotemporal dynamic is found for seizure localization, whose spatiotemporal properties are comparable with experimental observations, providing a new biophysical explanation of the temporally higher frequency, but spatially more localized cortical waves observed in genetic rodents that display characteristics of human absence epilepsy, from the perspective of large-scale brain dynamics. Predictions are also presented for further experimental test. Thus, we propose a dynamical mechanism to unify the global and focal aspects of absence epilepsy with focal absence seizures associated with seizure localization, and the global ones associated with seizure generalization. We are seeking more real data to compare with the model, and to decide whether and how to add more details of cellular nonlinear dynamics or heterogeneous connectivity into the large-scale brain dynamics.
报告人简介:
杨冬平博士,悉尼大学物理系复杂系统研究组博士后。2011年毕业于厦门大学,获得生物物理博士学位。2011-2015香港浸会大学非线性研究中心博士后。目前的研究工作利用计算模拟和非线性动力学理论分析来理解大脑系统中临界动力学的时空特点以及探寻潜在的预警信号,例如大脑清醒到睡眠的转变过程及其潜在的预警信号,正常状态到癫痫状态的不同转变类型,以及癫痫的扩散过程。
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2018年12月27日