大鼠水浸应激过程中心电信号的非线性特征与自主神经调制状况研究

Research on Nonlinear Characteristic of ECG Signals and Tone of Autonomic Nervous System during Water-immersion Restraint Stress in Rats.

目的通过分析心电信号的非线性特征,明确大鼠水浸应激过程中自主神经系统功能调制状况,并探讨近似熵与分形标度指数变化与自主神经系统功能调制状况的关系。方法记录大鼠在单纯捆绑、水浸应激以及切断副交感神经水浸过程的心电信号,计算RR间期的近似熵和分形标度指数,并进行统计分析。结果水浸应激后,切断副交感神经水浸组与对照组相比,以及切断副交感神经水浸组内不同时间段间相比,两个指标变化均没有显著性差异。其他两组近似熵的变化趋势为,水浸组明显升高,束缚对照组明显下降。同应激前相比应激后大鼠心率的分形标度指数的变化趋势为,水浸组明显降低,其数值均小于0.5,对照组明显升高,除了第5小时以外,其他时段数值均大于0.5。结论在大鼠水浸应激过程中,近似熵升高,分形标度指数下降,副交感神经兴奋性增强,副交感神经活动占主要优势。

Objective To definite the status of tone of autonomic nervous system during water immersion process by analyzing the nonlinear characteristic of ECG signals ; To explore the relation of approximate entropy （ApEn）, scaling exponent （α） changes and modulation function status of autonomic nervous system. Methods The ECG signals of rats during the process of restraint stress （RS） , water-immersion restraint stress （WRS） and Vagotomy and Water-immersion restraint stress （vagotomy-WRS） were recorded. The ApEn and of RR intervals were calculated. Results After the stress, the differences of the value of ApEn and α of RR intervals between RS and vagotomy-WRS groups and between different periods in vagotomy-WRS group were not significant. The value of ApEn increased in WRS group and decreased in RS group significantly. Compared with pre-stress,α showed decreased trend, all of the values smaller than 0.5 in WRS group and increased obviously, most values larger than 0.5 in RS group. Conclusion The increased ApEn and decreased α indicates a higher intensity of parasympathetic activity. The parasympathetic activity is the predominant response of autonomic nervous system during water immersion process.