Strain Misty M, Conley Nicholas J, Kauffman Lily S, Espinoza Liliana, Fedorchak Stephanie, Martinez Patricia Castro, Crook Maisie E, Jalil Maira, Hodes Georgia E, Abbott Stephen B G, Güler Ali D, Campbell John N, Boychuk Carie R
Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX.
Department of Biology, University of Virginia, Charlottesville, VA.
bioRxiv. 2023 Dec 17:2023.11.14.566855. doi: 10.1101/2023.11.14.566855.
Cardiovagal neurons (CVNs) innervate cardiac ganglia through the vagus nerve to control cardiac function. Although the cardioinhibitory role of CVNs in nucleus ambiguus (CVN) is well established, the nature and functionality of CVNs in dorsal motor nucleus of the vagus (CVN) is less clear. We therefore aimed to characterize CVN anatomically, physiologically, and functionally. Optogenetically activating cholinergic DMV neurons resulted in robust bradycardia through peripheral muscarinic (parasympathetic) and nicotinic (ganglionic) acetylcholine receptors, but not beta-1-adrenergic (sympathetic) receptors. Retrograde tracing from the cardiac fat pad labeled CVN and CVN through the vagus nerve. Using whole cell patch clamp, CVN demonstrated greater hyperexcitability and spontaneous action potential firing despite similar resting membrane potentials, compared to CVN. Chemogenetically activating DMV also caused significant bradycardia with a correlated reduction in anxiety-like behavior. Thus, DMV contains uniquely hyperexcitable CVNs capable of cardioinhibition and robust anxiolysis.
心迷走神经元（CVNs）通过迷走神经支配心脏神经节以控制心脏功能。尽管延髓疑核中的CVNs（CVN）的心脏抑制作用已得到充分证实，但迷走神经背核中的CVNs（CVN）的性质和功能尚不清楚。因此，我们旨在从解剖学、生理学和功能上对CVN进行表征。光遗传学激活胆碱能迷走神经背核神经元通过外周毒蕈碱（副交感神经）和烟碱（神经节）乙酰胆碱受体导致强烈的心动过缓，但不通过β-1-肾上腺素能（交感神经）受体。从心脏脂肪垫进行逆行追踪通过迷走神经标记了CVN和CVN。使用全细胞膜片钳技术，与CVN相比，尽管静息膜电位相似，但CVN表现出更高的兴奋性和自发动作电位发放。化学遗传学激活迷走神经背核也导致显著的心动过缓，并伴有焦虑样行为的相关减少。因此，迷走神经背核包含具有独特高兴奋性的CVNs，能够进行心脏抑制和强大的抗焦虑作用。
