The Dynamics Mechanism Research Of Neuronal Excited Mode

It’s an important problem in neuroscience to study the dynamical behaviors of neuron, which is the fundamental structural and functional unit of neural system. It is amazing that neuron can rapidly and precisely react with different external stimulations and influence coming from adjacent neurons to efficiently complete complicated task, even though the external environment of neuron is completely complex in real conditions. Scientists construct various mathematic models based on Hodgkin-Huxley (HH) model to simulate the neuron activities and study the dynamics behavior mechanism.In this paper, we studied the neurons’ response and spiking phenomenon, which is effected by different external environment or stimulus. The model is based on the classical Morris-Lecar neuronal model. Firstly, for the continued external DC stimulation, the response of neuron is more quickly and sensitive with the increase of the DC strength, the discharge frequency of neuron is increasing as well, i.e. discharge is speeding up. Then, for the sinusoidal electric current of fixed frequency, the ML neuron exhibits rich excited behaviors as change of potassium balance potential. But the burster frequency of neuron is corresponding with the frequency of external received current all the way, that is to say the burster discharge of neuron is frequency depended in the periodic stimulated current. Izhikevich make a modification on ML model, so that there are different bursters at different balance potential of calcium or potassium. From the simulation, we discover that the balance potential of calcium and potassium have opposite effect on neuron’ response, meanwhile, calcium channel is more sensitive than potassium channel. In addition, there are some reentrance phenomenon in Izhikevich modified ML model, which prove that ion channel balance potentials have certain correlation between calcium and potassium.We have studied the neurons’ response and spiking phenomenon caused by different external environment or stimulus, it is benefit to further explore the dynamical behavior of nervous system in more complex external surroundings. And it has a certain role in understanding the influence of external environment on excitability of biological nervous system and pathogenesis of several neurological diseases.