突触噪声对神经元兴奋性调节的模型研究

A mathematical model of the membrane characteristics of motoneurons under similar physiological conditions is established based on the previous studies on the firing patterns of neurons under synaptic input. The established model reproduces the basic form of neuron firing in the two cases of with or without synaptic noise; and membrane oscillation was reproduced in the case of synaptic noise. On the basis of this, the number, amplitude and threshold of action potentials in the two cases are described quantitatively. Compared with double-ramp stimulation, the excitatory synaptic input increases the number of action potentials by about 16, but the excitation threshold is increased; while the inhibitory synaptic input decreases the number of action potentials by about 19, and the excitation threshold is decreased. In the case of the inhibitory and mixed synaptic inputs, the amplitude increment of action potential are significantly smaller than those at double-ramp stimulation, and the average values are decreased by 0.68 mV and 0.33 mV, respectively. The mathematical model can well simulate the neuron action potentials with membrane oscillation, which provides an approach and a basis for the subsequent analysis of electrophysiological neurons and the pathological study on cell firing.