不同类型突触输入对电突触连接神经元同步化放电的调控
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摘要
目的同步化放电在神经信息传递和编码过程中极为重要,如何调控神经元之间的同步化放电也一直是脑科学研究的热点之一。本文利用计算机模拟的方法,研究突触输入类型和相对强度的不同对同步化放电活动的调控作用。方法首先基于Izhikevich神经元模型,构造一个三神经元网络,然后添加不同类型的突触输入(电突触、兴奋性化学突触及抑制性化学突触),最后设定其中一个神经元为调控器,分析另外两个神经元的同步化放电活动。结果对于电突触和兴奋性化学突触输入,当两个神经元接收到的输入强度接近时,同步性会增强,反之则会减弱。而对于抑制性化学突触输入,当调控器神经元的放电频率较低时,同步性的变化与电突触和兴奋性化学突触的情况类似;当调控器神经元的频率较高时,同步化活动显著地被压制。结论电突触连接神经元之间的同步化活动会受到外界突触输入类型及相对大小的调控,为进一步探索神经系统中同步化活动的起源和调控提供了参考。
Objective Synchronous firings exhibit important roles in neural information transmission and encoding,and how to efficiently modulate neuronal synchronizations is always one of the hot spots in brain science research. By means of computer simulations,this paper aims to investigate how synaptic types and relative strengths modulate the synchronization between electrically coupled neurons. Methods Based on the Izhikevich neuron model,a three-neuron network was constructed. By setting one neuron as a modulator,synchronous activities between the other two neurons were numerically analyzed. Results For electrical coupling and excitatory chemical coupling,synchronization strength between the two neurons could be enhanced if the two neurons received synaptic inputs with similar weights. However if the two neurons received synaptic inputs with rather different weights,the synchronization strength could be significantly weakened. For inhibitory chemical coupling,the same conclusion could be drawn when firing frequency of the modulator was low; while higher frequency of the modulator can almost completely suppress the synchronization irrespective of the relative synaptic weights. Conclusions Synchronization strength between electrically coupled neurons can be effectively modulatedby the external synaptic inputs,this result promote the exploration about initiation and modulation of synchronization in nervous system.
Objective Synchronous firings exhibit important roles in neural information transmission and encoding,and how to efficiently modulate neuronal synchronizations is always one of the hot spots in brain science research. By means of computer simulations,this paper aims to investigate how synaptic types and relative strengths modulate the synchronization between electrically coupled neurons. Methods Based on the Izhikevich neuron model,a three-neuron network was constructed. By setting one neuron as a modulator,synchronous activities between the other two neurons were numerically analyzed. Results For electrical coupling and excitatory chemical coupling,synchronization strength between the two neurons could be enhanced if the two neurons received synaptic inputs with similar weights. However if the two neurons received synaptic inputs with rather different weights,the synchronization strength could be significantly weakened. For inhibitory chemical coupling,the same conclusion could be drawn when firing frequency of the modulator was low; while higher frequency of the modulator can almost completely suppress the synchronization irrespective of the relative synaptic weights. Conclusions Synchronization strength between electrically coupled neurons can be effectively modulatedby the external synaptic inputs,this result promote the exploration about initiation and modulation of synchronization in nervous system.
引文
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