Can neurons in the nucleus ambiguus selectively regulate cardiac rate and atrio-ventricular conduction?
Can neurons in the nucleus ambiguus selectively regulate cardiac rate and atrio-ventricular conduction?
复制标题
DOI：
10.1016/0165-1838(95)00104-2
复制
发表时间：
1996-02-05
期刊：
影响因子：
--
通讯作者：
Massari, VJ
中科院分区：
文献类型：
--
作者：
Gatti, PJ;Johnson, TA;Massari, VJ
在生理选择性的心内副交感神经节内注入逆行示踪剂后，在疑核腹外侧核（NA-VL）内发现负性变时性和负性变导性神经元的分布。负性变导性神经元优先分布在NA-VL的头端（rNA-VL）。负性变时神经元主要分布在尾侧NA-VL（cNA-VL）。观察到这两种类型的心脏抑制神经元的显着数量重叠的中间水平的NA-VL（iNA-VL）。在本报告中，我们研究了微量注射兴奋性氨基酸谷氨酸（GLU）到cNA-VL和iNA-VL对心率和AV传导的影响，同时记录起搏和非起搏猫心脏的心电图。数据表明：（i）cNA-VL中神经元的兴奋导致心率降低58 +/-17%，而不影响AV传导;和（ii）iNA-VL中神经元的兴奋引起心率降低（68 +/- 12%）和AV传导率降低这些生理学结果支持以下解剖学推断：cNA-VL中从生理学选择性副交感心内神经节逆行标记的神经元选择性地表现出负性变时特性。此外，这些数据表明，有一个纵向的心脏组织负变时性和负dromotropic神经元在NA-VL。这种中枢神经系统组织反映了迷走神经功能选择性心脏成分的外周组织，最后，数据与解剖学分离和功能选择性副交感神经节前迷走神经运动神经元在NA独立控制心率和AV传导的假设是一致的。
Previous anatomic data have described the distribution of presumptive negative chronotropic and negative dromotropic neurons in the ventro-lateral nucleus ambiguus (NA-VL) following injections of retrograde tracers into physiologically selective parasympathetic intracardiac ganglia, Negative dromotropic neurons were preferentially distributed in the rostral NA-VL (rNA-VL). Negative chronotropic neurons were preferentially distributed in the caudal NA-VL (cNA-VL). Significant numbers of both types of cardio-inhibitory neurons were observed to overlap in an intermediate level of the NA-VL (iNA-VL). In the present report, we have examined the effects of microinjections of the excitatory amino-acid glutamate (GLU) into the cNA-VL and iNA-VL on cardiac rate and AV conduction while recording the electrocardiogram in paced and non-paced cat hearts. The data indicate that: (i) excitation of neurons in the cNA-VL causes a 58 +/- 17% reduction in cardiac rate, without influencing AV conduction; and (ii) excitation of neurons in the iNA-VL causes both a reduction in heart rate (68 +/- 12%) and a decrease in the rate of AV conduction (38 +/- 7%), These physiological results support the anatomical inference that neurons in the cNA-VL that are retrogradely labeled from physiologically selective parasympathetic intracardiac ganglia selectively exhibit negative chronotropic properties. Furthermore, the data indicate that there is a longitudinal cardiotopic organization of both negative chronotropic and negative dromotropic neurons in the NA-VL. This CNS organization mirrors the peripheral organization of functionally selective cardiac components of the vagus nerve, Finally, the data are consistent with the hypothesis that anatomically separated and functionally selective parasympathetic preganglionic vagal motoneurons in the NA independently control cardiac rate and AV conduction.