CENTRAL RESPIRATORY MODULATION OF MEDULLARY SYMPATHOEXCITATORY NEURONS IN RAT
CENTRAL RESPIRATORY MODULATION OF MEDULLARY SYMPATHOEXCITATORY NEURONS IN RAT
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DOI：
10.1152/ajpregu.1989.256.3.r739
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发表时间：
1989-03-01
影响因子：
--
通讯作者：
GUYENET, PG
中科院分区：
文献类型：
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作者：
HASELTON, JR;GUYENET, PG
中枢呼吸发生器对交感神经放电产生调节影响。在猫中，延髓头腹外侧 (RVL) 的交感兴奋神经元也表现出中枢呼吸调节。由于 RVL 交感兴奋性神经元主要负责维持交感血管舒缩张力，因此这些神经元的调节很可能解释了交感神经放电的中枢呼吸调节。在本研究中，进行实验来表征氟烷麻醉大鼠腰交感神经放电（LSND）的呼吸调节模式。膈触发的 LSND 平均值表现出与膈爆发开始一致的小凹陷，随后是与膈爆发停止一致的大峰值。膈触发的 RVL 交感兴奋神经元活动直方图显示出三种中枢呼吸调节模式：吸气抑制 (I)、吸气峰值 (II) 和早期吸气抑制，随后出现吸气后峰值 (III)，这种模式与 LSND 中看到的模式非常相似。神经记录和单单元记录实验均在具有或不具有完整压力感觉传入的迷走神经切断大鼠中进行。结果比较表明，在大鼠中，压力感受反射不会改变或促进交感神经输出的中枢呼吸调节。最后，对 RVL 中假定的非肾上腺素能起搏器样神经元和假定的 C1 肾上腺素能神经元进行了比较。中枢呼吸调节模式没有发现差异。
The central respiratory generator exerts a modulatory influence on sympathetic nerve discharge. In cats the sympathoexcitatory neurons of the rostroventrolateral medulla (RVL) exhibit central respiratory modulation as well. Because RVL sympathoexcitatory neurons are largely responsible for the maintenance of sympathetic vasomotor tone, it is likely that the modulation of these neurons accounts for the central respiratory modulation of sympathetic discharge. In the present study experiments were performed to characterize the pattern of respiratory modulation of lumbar sympathetic nerve discharge (LSND) in the halothane-anesthetized rat. Phrenic-triggered averaging of LSND exhibited a small depression coincident with the onset of the phrenic burst followed by a large peak that was coincident with the cessation of the phrenic burst. Phrenic-triggered histograms of the activity of RVL sympathoexcitatory neurons exhibited three patterns of central respiratory modulation: inspiratory depression (I), inspiratory peak (II), and early inspiratory depression followed by a postinspiratory peak (III), a pattern that was very similar to that seen in LSND. Both nerve recording and single-unit rcording experiments were performed in vagotomized rats with or without intact barosensory afferents. A comparison of the results suggested that, in the rat, the baroreflex does not modify or contribute to the central respiratory modulation of sympathetic output. Finally, a comparison was made between presumed nonadrenergic pacemaker-like neurons and putative C1 adrenergic neurons in the RVL. No differences were found in the patterns of central respiratory modulation.