Control of arterial pressure variability by heart rate variability through spinal cord in brain damage

心率变异性的功率谱分析可以评估心脏自主神经功能。通过心率变异性(HRV)、动脉压(AP)变异性(APV)和HR与AP之间的脉冲反应(IR)分析，探讨脑和脊髓在急性损伤中的功能。16名受试者随机分为2组，分别接受C3-4脊髓横断和颅内球囊充气脑损伤。BS组在脑损伤前和脑损伤后分别记录在线数据。横断脊髓，记录数据。SB组先横断脊髓，再进行脑损伤，记录间隔与BS组相同。对心率变异性(HRV)和平均心率变异性(APV)进行分析，在低频段和高频段对频谱功率进行积分。用傅里叶变换和逆傅立叶变换分析HR到AP和AP到HR的IR。对组内和组间进行统计分析。脊髓横断使SB组和BS组HR降低，APV维持较高的交感迷走神经平衡，而脑损伤则降低了HRV的平衡。在HR对AP的最大IR中，脑损伤比脊髓损伤有显著影响，而AP对HR的最大IR没有影响。HRV是由大脑控制的，APV是由大脑通过脊髓介导的。在脑损伤中，APV由HRV通过脊髓控制。综上所述，我们揭示了脊髓和脑损伤动物自主神经活动的本质。提示脊髓不仅是脑冲动的传导系统，而且是自主神经冲动的外周传导器官。

Power spectral analysis of heart rate (HR) variability (HRV) can estimate the cardiac autonomic nervous system function. We investigated the function of brain and spinal cord in their acute injury by the analysis of HRV and arterial pressure (AP) variability (APV), and impulse response (IR) between HR and AP.16 subjects were randomly assigned into 2 groups to receive spinal cord transection at C3-4 and brain damage by inflating an intracranial balloon. In BS group, the on-line data were digitally recorded before the brain damage and thereafter. The spinal cord was transected and the data were recorded. In SB group, the spinal cord was transected firstly and the brain damage was made secondly with same recording intervals as BS group. HRV and APV were analyzed.Spectral power was integrated at low and high frequency band areas. IR of HR to AP and AP to HR were analyzed by Fourier and inverse-Fourier transformations using the data in time domain. Statistical analysis was made within a group and between the groups. p<0.05 was determined significant.Spinal transection depressed HR in SB group and BS group, and maintained sympathovagal balance high in APV, while brain damage depressed the balance in HRV. In maximal IR of HR to AP, brain damage had significant effect than spinal damage, while no effect was seen in IR of AP to HR. HRV is controlled by the brain and APV is mediated by the brain through the spinal cord. APV is controlled by HRV through spinal cord in brain damage.In conclusion, we revealed the nature of autonomic nervous activity in animals receiving spinal cord and brain damage. It was suggested that spinal cord is not only a conduction system of brain impulses but the organ showing peripheral conduction of autonomic impulses.