Study On The Blocking Effect Of Ion Channels In The Hodgkin-Huxley Neuron Model

Exploring in the field of neuroscience has always been a hot topic,and the exploration of neuron or the nervous system is the prerequisite for studying the mysteries of the human brain.In fact,neurons are in a complex environment and receive different external stimulus,which all affect the dynamic behavior of the nervous system.The signal transduction and transmission are accomplished through ion channels and synapses,respectively.Mathematical models can be used to simulate the true electrophysiological activities of neurons,which provide potential guidance for further cognition and research on brain mechanisms.In this paper,based on the Hodgkin-Huxley model,the ionic channel blockage effect is considered,multi-frequency external periodic signal,ion channel noise,electrical synaptic coupling,and chemical synaptic coupling are introduced into the model.Numerical simulation and nonlinear dynamics methods are used to study the various firing behaviors of neurons,and obtaining the following research results:(1)Considering the multi-frequency periodic signal,through the bifurcation analysis,it is found that:bifurcation points of neuron discharge are altered through tuning the amplitude of multi-frequency periodic signal,and the discharge cycle is changed by increasing the frequency of the signal.The frequency of spike discharge is increased through increasing ionic channel noise,and the neuron discharge is more stable by appropriately reducing ionic channel noise.The effect of ionic channel blockage on nerve discharge behavior indicates that the excitability of neuron is promoted by potassium channel blockage and it is inhibited by sodium channel blockage.It reveals that there is an optimal potassium channel blockage ratio at which the neuronal firing activity is the most regular,while the order of neural spike is disrupted by the sodium channel blockage.(2)Introducing electrical synaptic coupling to study the synchronization and response behavior of neurons.Research indicates:The synchronization of the firing of the two neurons increases with the increase of the electrical coupling strength.There is an optimal coupling strength to make the neuron's response to the external signal the best.When the electrical coupling is strong,the firing states of the two neurons are completely synchronized.The alternate firing pattern of cycle and chaos can be observed by adjusting the coupling strength.A moderate potassium channel blockage makes the neuron most responsive to the external signal.(3)Introducing chemical synaptic coupling to study the synchronization and response behavior of neurons.Research indicates:As the strength of chemical coupling increases,the synchronization of the firing of the two neurons is enhanced.The neuron's response to external signals increases with the increase of the coupling strength,and there is an obvious maximum.This response phenomenon is inhibited as the coupling strength further increases.For the extremely small coupling strength,the synchronization of the firing of the two neurons is first weakened and then increased with the increase of potassium channel blocking coefficient.When the coupling strength is large,the blockage of potassium channels has little effect on the synchronization of neuronal firing.Appropriate potassium channel blockage allows the neuron to respond optimally to external signal.