Gebber G L, Zhong S, Barman S M
Department of Pharmacology/Toxicology, Michigan State University, East Lansing 48824-1317, USA.
Am J Physiol. 1995 Jun;268(6 Pt 2):R1472-83. doi: 10.1152/ajpregu.1995.268.6.R1472.
We used phase spectral analysis to study the relationships between the cardiac-related discharges of pairs of postganglionic sympathetic nerves in urethan-anesthetized or decerebrate cats. Phase angle when converted to a time interval should equal the difference in conduction times from the brain to the nerves (i.e., transportation lag) if their cardiac-related discharges have a common central source. Transportation lag was estimated as the difference in the onset latencies of activation of the nerves by electrical stimulation of the medulla or cervical spinal cord. The phase angle for the cardiac-related discharges of two nerves was not always equivalent in time to the transportation lag. For example, in some cases the cardiac-related discharges of the renal nerve were coincident with or led those of the inferior cardiac nerve. In contrast, the electrically evoked responses of the renal nerve lagged those of the inferior cardiac nerve by > or = 32 ms. These observations are consistent with a model of multiple and dynamically coupled brain stem generators of the cardiac-related rhythm, each controlling a different sympathetic nerve or exerting nonuniform influences on different portions of the spinal sympathetic outflow.
我们采用相位谱分析方法，研究了在氨基甲酸乙酯麻醉或去大脑的猫中，节后交感神经对的心脏相关放电之间的关系。如果两条神经的心脏相关放电有共同的中枢来源，那么相位角转换为时间间隔后应等于从大脑到神经的传导时间之差（即传输延迟）。传输延迟通过电刺激延髓或颈脊髓激活神经的起始潜伏期之差来估计。两条神经的心脏相关放电的相位角在时间上并不总是等同于传输延迟。例如，在某些情况下，肾神经的心脏相关放电与下心神经的放电同时出现或超前于下心神经。相反，肾神经的电诱发反应比下心神经滞后≥32毫秒。这些观察结果与心脏相关节律的多个动态耦合脑干发生器模型一致，每个发生器控制不同的交感神经或对脊髓交感神经输出的不同部分施加不均匀的影响。
