Sequence of activation of ventrolateral and dorsal medullary sympathetic neurons.
Sequence of activation of ventrolateral and dorsal medullary sympathetic neurons.
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腹外侧和背侧髓质交感神经元的激活顺序。
DOI：
10.1152/ajpregu.1983.245.3.r438
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Gebber,GL
中科院分区：
文献类型：
--
作者：
Barman,SM;Gebber,GL
在本研究中描述了一种独特的方法来评估基底交感神经放电（SND）中心脏相关成分的潜在起源区域。具体地说，比较了猫腹外侧和背髓神经元与交感神经相关活动的放电时间。已知这两个髓质区域在维持血压方面起作用。尖峰触发平均和后R波间期分析用于识别单个延髓神经元的自发放电时间相关的肾或心下交感神经。使用我们实验室先前开发的心室起搏测试获得的结果使我们能够将这些神经元中的一些分类为控制SND的网络元素（即，髓质交感神经元）。该测试是基于这样的假设，即脑干交感神经元应该表现出在心率变化期间在时间上保持锁定到SND的心脏相关分量的峰值的放电，该心率变化改变了压力感受器和交感神经活动之间的相位关系。记录这些单位的放电的部位的电刺激引起SND增加，从而表明这些神经元subserved交感神经兴奋功能。平均而言，腹外侧髓神经元比背侧髓神经元在SND的心脏相关成分中晚48 ms放电。这一观点并不支持先前的建议[R。A. L. Dampney和E. A.月球Am.生理学杂志。239（心脏循环。Physiol.8）：H349-H358，1980]，基础交感神经紧张仅起源于腹外侧髓神经元的回路。本文还讨论了与维持血压有关的延髓背侧和腹外侧神经元的相互联系。
A unique approach to the problem of evaluating potential regions of origin of the cardiac-related component in basal sympathetic nerve discharge (SND) is described in the present investigation. Specifically a comparison was made of the firing times of cat ventrolateral and dorsal medullary neurons with sympathetic nerve-related activity. These two medullary regions are known to play a role in the maintenance of blood pressure. Spike-triggered averaging and post-R wave interval analysis were used to identify single medullary neurons with spontaneous discharges temporally related to those in the renal or inferior cardiac sympathetic nerve. The results obtained using a ventricular pacing test previously developed in our laboratory allowed us to classify some of these neurons as elements of networks that control SND (i.e., medullary sympathetic neurons). The test is based on the assumption that brain stem sympathetic neurons should exhibit discharges that remain locked in time to the peak of the cardiac-related component of SND during changes in heart rate that shift the phase relations between baroreceptor and sympathetic nerve activity. Electrical stimulation of sites from which the discharges of such units were recorded elicited increases in SND, thus suggesting that these neurons subserved a sympathoexcitatory function. On the average, ventrolateral medullary neurons fired 48 ms later than dorsal medullary neurons during the cardiac-related component in SND. This observation does not support the previous suggestion [R. A. L. Dampney and E. A. Moon. Am. J. Physiol. 239 (Heart Circ. Physiol. 8): H349-H358, 1980] that basal sympathetic tone originates exclusively in circuits of ventrolateral medullary neurons. Possibilities concerning the interconnections of dorsal and ventrolateral medullary neurons involved in maintaining blood pressure are discussed.