| Synchronous firing of the neuron system generally exists in the high-level cognitive activities of the brain. Abnormal synchronization in specific area of brain can cause various degenerative diseases. The electromagnetic radiation of the applied electric field has critical effects on normal characteristics of single neuron, and further the cluster synchronization is affected. Phase response curves, which describe the response to small perturbation, could be cellular indicator of network synchronization. Based on this, brain stimulation has become an effective physical therapy in neurological diseases. But brain stimulation still has some drawbacks and the mechanism of how the electro-magnetic effects of brain stimulation affect synchronization of neuron system is not quite clear. It is of great significance for the treatment of nervous system disease to explore the effects of electric field on network synchronization.The research of this thesis mainly includes the following three aspects:(1) Based on the transcritical hybrid model, we get different firing features in high and low calcium conductance. Then the effects of the applied currents and several key model parameters on neuron phase responses are obtained. We get the synchronization propensity of neuronal networks based on the phase response of a single neuron, as well as the relationship between the intrinsic properties of neurons and the synchronization of networks.(2) Neuronal dynamic characteristics of two-compartment model are investigated with different extra electric fields and morphological parameters. Then we give phase shifts of the two compartments responding to weak perturbation applied to soma or dendrite. By influencing the phase response of single neuron, the effects of applied electric fields and morphological parameter on synchronization propensity of neuron network is explored.(3) Based on the results of the transcritical hybrid model and two-compartment model, we analyze the mechanism of external stimulation and several key model parameters on phase response of single neuron from the perspective of excitatory and inhibitory competition. Then the relation between type and amplitudes of phase response curves and network synchronization is obtained. We get the internal causes of network synchronization preference.This thesis gives the relation of electric fields and synchronization of neuron system from the perspective of single neuron’s characteristics. It provides a novel ideal to research synchronization of neuron system and connects the intrinsic properties of neurons and synchronization propensity of neural networks. It is helpful to understand the potential pathogenesis of neurological disease caused by abnormal synchronization and has guiding significance for the treatment of these diseases. |
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