时间：5月12日（周一）上午10：00

地点：勤园20-518

报告简介：

Stimulus-dependent fast and slow conduction waves in the same nerve system have been shown experimentally, which give rise to two modes of nerve functions. We use computer simulations to show that the fast and slow waves are a bistable conduction caused by a positive feedback loop of the wavefront upstroke speed, mediated by the sodium channel inactivation properties, which is further potentiated by the presence of the calcium current. The theoretical insights provide a generic mechanism for stimulus-dependent fast and slow conduction in the nerve systems, which may be also applicable to other electrically excitable tissues, such as cardiac muscles. We also show that the positive feedback loop between sodium current activation and wavefront ramp-up speed causes a saddle-node bifurcation to result in bistable spiral waves in electrically excitable media, in which both slow and fast waves are triggered by different stimulation protocols. Moreover, the two types of spiral wave conduction may interact to give rise to more complex spiral wave dynamics. The transitions between different spiral wave behaviors via saddle-node bifurcation can be a candidate mechanism for transitions widely seen in cardiac arrhythmias and neural diseases.

报告人简介：

  张朝阳，宁波大学物理学院副教授，2015年博士毕业于北京师范大学，2019-2020 年在美国加州大学(UCLA)医学院进行博士后访问研究，研究方向为计算心律失常与计算神经科学。主持国家自然科学基金面上项目、青年基金，浙江省自然科学基金探索项目，博士后面上项目，宁波市自然科学基金等，获宁波市青年科技创新领军人才、宁波市领军拔尖人才项目。近年来以第一作者发表Physical Review Letter，Physical Review E等，合作完成一篇《中国科学》邀请综述。另外，在医学期刊发表一区top论文Circulation: Arrhythmia and Electrophysiology (Circulation: AE)、Journal of the American Heart Association (JAHA)、Heart Rhythm、JACC: Clinical Electrophysiology (JACC:EP)、Cell 旗下生物物理期刊Biophysical Journal等。