磁刺激作用下感生电场对网络同步的影响

磁刺激作为一种无侵入式的物理技术，在治疗某些精神疾病方面取得了一定的发展．但是由于对磁刺激和大脑之间的相互作用机制的认识不清，极大限制了此技术的发展．磁场对脑部的影响体现在其产生的感应电场可以调节神经网络的活动．在基于模型的基础上研究了磁场刺激作用下的感生电场对神经元及其网络的影响．在对直流感应电场的分析中，研究了电场强度、突触电导以及网络规模对网络同步的影响，并发现由抑制性中间神经元所组成的网络只能产生在gamma频段（30～80Hz）内的同步振荡；在对交流感应电场的分析中，发现只有当神经元处于单周期放电模式时才能产生同步的网络振荡．研究结果解释了感应电场对神经元及其网络的作用规律，有助于推动以磁刺激为核心技术治疗某些精神疾病的有效手段的进一步发展．

Effects of Induced Electric Field on Network Synchrony Under Magnetic Stimulation

Magnetic stimulation of the central nervous system is a successful therapeutic application, which can alle- viate the symptoms of a number of neurological disorders. Biological system is affected by the induced electric field （EF） when it is exposed to magnetic field. However, those techniques are limited for lack of the understanding of the underlying mechanisms supporting the interaction between magnetic stimulus and brain tissue. The effects of in- duced electric field on a single neuron and neural network were investigated from the viewpoint of biophysical model- ing. In the case of a static induced EF, the effects of the strength of the induced EF, snaptic conductance and net- work size on network activity were studied. The result shows that inhibitory intemeuronal network can only be syn- chronized within the range of gamma frequency （30--80 Hz）. In the case of a sinusoidal induced EF, the coherent network oscillation occurs only when each neuron fires spikes of regular period. The results can contribute to scientific theoretical studies regarding the effects of MS on human brain and motivate further development of magnetic stimula- tion on treatment of neurological diseases.