Neuromodulatory co-expression in cardiac vagal motor neurons of the Dorsal Motor Nucleus of the Vagus [RNAseq]. Neuromodulatory co-expression in cardiac vagal motor neurons of the Dorsal Motor Nucleus of the Vagus [RNAseq]

The activity of the cardiac vagal innervation is well known to be crucial to the maintenance of cardiac health, and to protect and recover the heart from injury. Only recently has this role been shown to depend on the activity of the underappreciated Dorsal Motor Nucleus of the Vagus (DMV). By combining neural tracing, transcriptomics, and 3D mapping in male and female Sprague Dawley rats we characterize cardiac-specific neuronal phenotypes in DMV. We find that the DMV cardiac-projecting neurons differentially express PACAP, CART, and synucleins, as well as evidence that they participate in neuromodulatory co-expression involving catecholamines. The significance of these findings is enhanced by previous knowledge of the role of PACAP at the heart and of the other neuromodulators in peripheral vagal targets. Overall design: Single neurons were microdissected from the Dorsal Motor Nucleus of the Vagus (DMV) in the brainstem after Fast Blue retrograde tracer was injected into the intrinsic cardiac nervous system of one female Sprague Dawley rat. Half of the samples are cardiac-projecting neurons labeled by Fast Blue and the other half are non-cardiac-projecting (non-Fast Blue).

心脏迷走神经支配的活性对维持心脏健康、保护心脏免受损伤并促进其修复至关重要，这一点已得到广泛认可。直至近年，人们才明确该功能依赖于此前未受充分重视的迷走神经背运动核（Dorsal Motor Nucleus of the Vagus, DMV）的活动。本研究结合神经示踪、转录组学与三维标测技术，对雌雄斯普拉格-道利（Sprague Dawley）大鼠的迷走神经背运动核内心脏特异性神经元表型进行了系统表征。研究发现，投射至心脏的DMV神经元可差异性表达PACAP、CART及突触核蛋白，同时存在其参与儿茶酚胺类神经调质共表达的相关证据。鉴于此前已明确PACAP在心脏中的作用以及其他神经调质在外周迷走神经靶标中的功能，本研究结果的科学意义进一步凸显。实验整体设计：向1只雌性斯普拉格-道利大鼠的心脏内在神经系统注射快蓝（Fast Blue）逆行示踪剂后，从脑干的迷走神经背运动核（DMV）中显微切割分离单个神经元。其中一半样本为经快蓝标记的心脏投射神经元，另一半为未被快蓝标记的非心脏投射神经元。