Ando S, Imaizumi T, Harada S, Suzuki S, Sugimachi M, Sunagawa K, Hirooka Y, Takeshita A
Research Institute of Angiocardilogy, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
J Auton Nerv Syst. 1994 May;47(3):189-99. doi: 10.1016/0165-1838(94)90180-5.
We examined whether modulation of sympathetic nerve discharges (SND) by changes in carotid sinus pressure (CSP) is influenced by the pattern of the rhythm of central sympathetic neurons and whether the rhythm of the sympathetic nerve derived from central sympathetic neurons and that from the inputs from baroreceptors can coexist in postganglionic renal SND. In alpha-chloralose-anesthetized rabbits with aortic denervation and vagotomy, firing of central sympathetic neurons was at first left spontaneous and then driven artificially at 3 Hz by peroneal nerve stimulation. Under these conditions, renal SND were recorded and compared while CSP was altered at low frequencies. When central sympathetic neurons were firing spontaneously and low frequency oscillation was applied to CSP, two kinds of oscillation were noted in SND; first oscillation at the same frequency as that of central sympathetic neurons, and second oscillation of CSP changes. Power spectra of SND also showed two peaks at these two oscillations. When central sympathetic neurons regularly discharged at 3 Hz by electrical stimulation and CSP was kept constant, the power spectra of SND had a discrete single peak at 3 Hz. When a regular oscillation was applied to CSP at 1 Hz, the amplitude of central sympathetic outflow at 3 Hz was modulated at 1 Hz without disturbance of the frequency of the central 3 Hz rhythm. In other words, two apparently different rhythms coexisted in SND. In the power spectra, two discrete peaks were noted at the frequency of CSP changes and at the central sympathetic oscillation. When SND were averaged by CSP-triggered summation during spontaneous or artificial 3 Hz central firing, it was revealed that the shape of these two averaged SND were completely same in spite of obviously different central firing patterns. Nadir of SND occurred about 400 ms after the peak of CSP during changes in CSP at several frequencies in these two conditions. Thus, these results indicated two points; (1) CSP changes modulate the amplitude of SND in the same manner irrespective of the frequency or pattern of discharge of central sympathetic neurons; (2) both of frequency components of SND induced by oscillatory changes in central sympathetic neurons and oscillatory inhibitory input from baroreceptors can coexist even if their frequencies were different.
我们研究了颈动脉窦压力（CSP）变化对交感神经放电（SND）的调节是否受中枢交感神经元节律模式的影响，以及源自中枢交感神经元的交感神经节律与来自压力感受器输入的节律是否能共存于节后肾SND中。在接受主动脉去神经支配和迷走神经切断术的α-氯醛糖麻醉兔中，中枢交感神经元的放电起初任其自发进行，然后通过腓总神经刺激以3Hz的频率人工驱动。在这些条件下，记录肾SND并在低频改变CSP时进行比较。当中枢交感神经元自发放电且对CSP施加低频振荡时，在SND中观察到两种振荡；第一种振荡频率与中枢交感神经元相同，第二种振荡与CSP变化同步。SND的功率谱在这两种振荡频率处也显示出两个峰值。当通过电刺激使中枢交感神经元以3Hz规律放电且CSP保持恒定时，SND的功率谱在3Hz处有一个离散的单峰。当以1Hz对CSP施加规律振荡时，3Hz时中枢交感神经输出的幅度在1Hz处受到调制，而不干扰中枢3Hz节律的频率。换句话说，在SND中两种明显不同的节律共存。在功率谱中，在CSP变化频率和中枢交感神经振荡频率处观察到两个离散的峰值。当在自发或人工3Hz中枢放电期间通过CSP触发求和对SND进行平均时，结果显示尽管中枢放电模式明显不同，但这两种平均SND的形状完全相同。在这两种情况下，在几个频率的CSP变化期间，SND的最低点出现在CSP峰值后约400毫秒。因此，这些结果表明两点：（1）无论中枢交感神经元放电的频率或模式如何，CSP变化均以相同方式调节SND的幅度；（2）即使中枢交感神经元的振荡变化和压力感受器的振荡抑制输入的频率不同，它们在SND中诱导的频率成分也能共存。
