Guyenet P G, Brown D L
Am J Physiol. 1986 Jun;250(6 Pt 2):R1081-94. doi: 10.1152/ajpregu.1986.250.6.R1081.
Two classes of medullospinal units with inhibitory baroreceptor inputs [nucleus paragigantocellularis lateralis (PGCL) units] were recorded in PGCL (conduction velocity 3.1 and 0.67 m/s, respectively). Single-pulse stimulation of PGCL produced two peaks of activation of the lumbar sympathetic chain [sympathetic nerve discharge (SND)] with latencies of 98 and 206 ms. After substracting the delay due to impulse propagation between cord and sympathetic chain (64 ms), a conduction velocity of 2.8 and 0.67 m/s could be estimated for the medullospinal portion of the two sympathoexcitatory pathways stimulated in the PGCL. R wave-triggered activity histograms of PGCL unit discharge and lumbar SND exhibited a similar pattern with one major trough, occurring 108 ms later at the level of the sympathetic chain. It is concluded that PGCL contains two classes of medullospinal neurons with sympathoexcitatory function, the fast-conducting type being predominantly responsible for the cardiac-related rhythm of lumbar SND. Finally, averaging techniques revealed a large respiratory rhythm of lumbar SND in spontaneously breathing rats, but little or no such rhythm could be detected at the level of most PGCL sympathoexcitatory cells.
在外侧旁巨细胞旁核（PGCL）中记录到两类具有抑制性压力感受器输入的延髓脊髓单位（PGCL单位）（传导速度分别为3.1和0.67米/秒）。对PGCL进行单脉冲刺激产生了腰交感神经链激活的两个峰值[交感神经放电（SND）]，潜伏期分别为98和206毫秒。在减去脊髓与交感神经链之间冲动传播所导致的延迟（64毫秒）后，可以估算出在PGCL中受到刺激的两条交感兴奋通路的延髓脊髓部分的传导速度分别为2.8和0.67米/秒。PGCL单位放电和腰段SND的R波触发活动直方图呈现出相似的模式，在交感神经链水平出现一个主要低谷，延迟108毫秒。得出的结论是，PGCL包含两类具有交感兴奋功能的延髓脊髓神经元，快速传导型主要负责腰段SND与心脏相关的节律。最后，平均技术显示，在自主呼吸的大鼠中，腰段SND存在较大的呼吸节律，但在大多数PGCL交感兴奋细胞水平几乎检测不到这种节律。
