不同频率针刺手法诱发脊髓背角广动力范围神经元放电模式的非线性分析

目的 应用非线性动力学方法探讨不同频率针刺手法诱发脊髓背角广动力范围(wide dynamic range，WDR)神经元放电信号的编码特征。方法 采用玻璃微电极细胞外记录技术判定SD大鼠脊髓背角WDR神经元；不同频率(0.5、1、2、3 Hz)均匀提插手法针刺大鼠足三里穴；利用非线性动力学方法提取并分析脊髓背角WDR神经元放电信号中所包含的与针刺频率相关的特征性信息，通过计算放电频率、峰峰间期、嵌入维数、最大Lyapunov指数以及Lempel Ziv复杂度，得到不同频率针刺手法诱发WDR神经元放电信号的编码特征。结果 4种不同频率针刺手法表现出不同的特征，WDR神经元放电频率的变化与针刺手法频率的改变并非呈简单的线性相关；针刺作用下WDR神经元的放电信号具有混沌特性。结论 采用非线性动力学的相关术语描述和归纳针刺电信号的放电节律形式是适用可行的，不同频率针刺手法能够在脊髓背角水平干预神经电信息的传导、编码和加工过程。

Nonlinear Dynamic Analysis of Electrical Signals of Wide Dynamic Range Neurons in the Spinal Dorsal Horn Evoked by Acupuncture Manipulation at Different Frequencies

Objective To study the encoding information of electrical signals of wide dynamic range (WDR) neurons in the spinal dorsal horn evoked by acupuncture manipulation at different frequencies using nonlinear dynamics analysis. Methods Microelectrode extracellular recordings were used to observe the WDR neuron discharge evoked by acupuncture manipulation at Zusanli point (ST36) with different frequencies (0.5, 1, 2, and 3 Hz) in SD rats. The nonlinear dynamics analysis method was used to extract the nonlinear characteristic parameters, such as interspike interval, the Lyapunov exponent, Lempel-Ziv complexity, and the neural coding of the electrical signal evoked by acupuncture manipulations at different frequencies. Results Different characteristics were manifested with acupuncture manipulations at 4 different frequencies. More than a simple linear correlation was shown between the firing rate of the WDR neurons and the frequency of the acupuncture manipulation. The electrical signals evoked by acupuncture manipulation at Zusanli point (ST36) showed distinguished chaotic features. Conclusions It is applicable and feasible to describe and summarize the rhythm of the acupuncture electrical signal using the concepts and terminology of the nonlinear dynamics. Different acupuncture manipulation methods could interfere the transmission, coding, and processing of electrical signals in the spinal dorsal horn.