AREAS OF ROSTRAL MEDULLA PROVIDING TONIC CONTROL OF RENAL AND SPLENIC NERVES
AREAS OF ROSTRAL MEDULLA PROVIDING TONIC CONTROL OF RENAL AND SPLENIC NERVES
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DOI：
10.1152/ajpheart.1991.261.6.h1687
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发表时间：
1991-12-01
影响因子：
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通讯作者：
WEAVER, LC
中科院分区：
文献类型：
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作者：
BELULI, DJ;WEAVER, LC
本研究的目的是确定是否不均匀的控制紧张性放电的肾和脾神经的延髓头端腹外侧（RVLM）是依赖于内脏代表的肾脏和脾脏在这一地区。小（15 nl，13 pmol）注射有效的tau-氨基丁酸激动剂蝇蕈醇被用来映射麻醉大鼠的RVLM，寻找区域，选择性地提供紧张性兴奋的肾或脾神经。大多数蝇蕈醇微量注射产生降压反应和抑制交感神经活动。肾神经的活动受到抑制显着超过脾神经，但我们没有发现证据的RVLM的地形组织对这两个神经的紧张活动的影响。然而，这项研究确实产生了一个重要的新观察结果，因为大约10%的注射引起了升压反应和交感神经放电的增加。意外的增加一定是由位于整个RVLM的紧张性活性交感抑制神经元的小团体的封锁。这种去抑制不是从RVLM的任何特定区域引起的。总之，RVLM神经元和假定的中间神经元，紧张性控制节后肾和脾神经元的放电似乎均匀分布在整个区域。无论是兴奋性或抑制性元素组织地形，专门影响肾或脾神经。负责肾神经的优先效应的神经组织可能存在于RVLM内的局部微电路中，并且仅通过对这些电路进行更离散的分析来揭示。
The objective of this study was to determine whether nonuniform control of tonic discharge of renal and splenic nerves by the rostral ventrolateral medulla (RVLM) is dependent on viscerotopic representation of the kidney and the spleen in this region. Small (15 nl, 13 pmol) injections of the potent tau-aminobutyric acid agonist muscimol were used to map the RVLM of anesthetized rats, searching for areas that selectively provided tonic excitation of renal or splenic nerves. Most of the muscimol microinjections produced depressor responses and inhibition of sympathetic nerve activity. Activity of renal nerves was inhibited significantly more than that of splenic nerves, but we found no evidence for topographical organization of RVLM influences on tonic activity of these two nerves. However, this investigation did yield an important new observation, since approximately 10% of the injections caused pressor responses and increases in sympathetic discharge. The unexpected increases must have been caused by blockade of small groups of tonically active sympathoinhibitory neurons located throughout the RVLM. This disinhibition was not evoked from any specific region of the RVLM. In conclusion, the RVLM neurons and putative interneurons that tonically control the discharge of postganglionic renal and splenic neurons appear to be distributed homogeneously throughout this area. Neither excitatory nor inhibitory elements were organized topographically to specifically influence the renal or the splenic nerve. The neural organization responsible for the preferential effect on renal nerves may exist in the local microcircuitry within the RVLM and will be revealed only by an even more discrete analysis of these circuits.