DIFFERENTIAL DRIVES FROM ROSTRAL VENTROLATERAL MEDULLARY NEURONS TO 3 IDENTIFIED SYMPATHETIC OUTFLOWS
DIFFERENTIAL DRIVES FROM ROSTRAL VENTROLATERAL MEDULLARY NEURONS TO 3 IDENTIFIED SYMPATHETIC OUTFLOWS
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DOI：
10.1152/ajpregu.1994.267.4.r935
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发表时间：
1994-10-01
影响因子：
2.8
通讯作者：
MAY, CN
中科院分区：
文献类型：
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作者：
MCALLEN, RM;MAY, CN
在氯醛糖麻醉的猫，同时记录肌肉血管收缩(MVC)、内脏血管收缩(VVC)和肾(RSN)交感纤维。显示它们的压力敏感性，然后切断所有压力感受器神经。将谷氨酸钠(5nL，0.1M)多次微量注射于4只动物的延髓头端腹外侧加压区(RVLM)。注射使血压增加高达87+/-22毫米汞柱，MVC、VVC和RSN活性分别增加169+/-55、62+/-23和67+/-36%。MVC与WC、MVC与RSN、VVC与RSN在5/7、6/7和1/7RVLM注射时，神经之间的相对反应(成对)显示出显著的不均匀。计算表明，总体而言，RVLM谷氨酸注射引起的反应尖峰不到一半可以由以固定比例兴奋MVC、VVC和RSN流出的假想神经元群体解释。分别在7/7、3/7和5/7的RVLM中发现了专门驱动MVC、VVC或RSN外流的部位。选择性地驱动一对给定神经中的任何一条神经的网站无处不在。可以启动三个流出的RVLM领土重叠，但显示出明显的差异。它们的形状和大小在不同的动物之间，甚至在不同的侧面都不同。它们覆盖了面下核(SRF)加上一个可变的旋转内侧延伸。这些数据支持这样一种观点，即驱动这三种交感神经流出的RVLM神经元在很大程度上，也许是完全不同的群体。
Simultaneous recordings were made in chloralose-anesthetized cats from muscle vasoconstrictor (MVC), visceral vasoconstrictor (VVC), and renal (RSN) sympathetic fibers. Their barosensitivity was demonstrated, after which all baroreceptor nerves were cut. Multiple microinjections of sodium glutamate (5 nl, 0.1 M) were made in a grid pattern covering the rostral ventrolateral medulla (RVLM) presser area on seven sides of four animals. Injections increased blood pressure by up to 87 +/- 22 mmHg and MVC, VVC, and RSN activities by up to 169 +/- 55, 62 +/- 23, and 67 +/- 36%, respectively. The relative responses between nerves (taken in pairs) showed significant inhomogeneity across injections into 5/7, 6/7, and 1/7 RVLMs for MVC vs. WC, MVC vs. RSN, and VVC vs. RSN, respectively. Calculation showed that overall, less than half the response spikes due to RVLM glutamate injections could be accounted for by a hypothetical population of neurons that excited MVC, VVC, and RSN outflows in fixed proportion. Sites that exclusively drove MVC, VVC, or RSN outflows were found in 7/7, 3/7, and 5/7 RVLMs, respectively. Sites that selectively drove either nerve of a given pair were ubiquitous. The RVLM territories from which the three outflows could be activated overlapped but showed clear differences. Their shapes and sizes differed between animals and even between sides. They covered the subretrofacial (SRF) nucleus plus a variable rostromedial extension. The data support the view that the RVLM neurons driving these three sympathetic outflows are largely, perhaps entirely, separate populations.