Dorsal motor vagal neurons can elicit bradycardia and reduce anxiety-like behavior
Misty M. Strain,
Nicholas J. Conley,
Lily S. Kauffman,
Liliana Espinoza,
Stephanie Fedorchak,
Patricia Castro Martinez,
Maisie E. Crook,
Maira Jalil,
Georgia E. Hodes,
Stephen B.G. Abbott,
Ali D. Güler,
John N. Campbell,
Carie R. Boychuk
Affiliations
Misty M. Strain
Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
Nicholas J. Conley
Department of Biology, University of Virginia, Charlottesville, VA, USA
Lily S. Kauffman
Department of Biology, University of Virginia, Charlottesville, VA, USA
Liliana Espinoza
Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
Stephanie Fedorchak
Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
Patricia Castro Martinez
Neuroscience Undergraduate Major, University of Virginia, Charlottesville, VA, USA
Maisie E. Crook
Department of Biology, University of Virginia, Charlottesville, VA, USA
Maira Jalil
Department of Biology, University of Virginia, Charlottesville, VA, USA
Georgia E. Hodes
School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
Stephen B.G. Abbott
Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
Ali D. Güler
Department of Biology, University of Virginia, Charlottesville, VA, USA
John N. Campbell
Department of Biology, University of Virginia, Charlottesville, VA, USA; Corresponding author
Carie R. Boychuk
Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA; Corresponding author
Summary: Cardiovagal neurons (CVNs) innervate cardiac ganglia through the vagus nerve to control cardiac function. Although the cardioinhibitory role of CVNs in nucleus ambiguus (CVNNA) is well established, the nature and functionality of CVNs in dorsal motor nucleus of the vagus (CVNDMV) is less clear. We therefore aimed to characterize CVNDMV 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 CVNNA and CVNDMV through the vagus nerve. Using whole-cell patch-clamp, CVNDMV demonstrated greater hyperexcitability and spontaneous action potential firing ex vivo despite similar resting membrane potentials, compared to CVNNA. Chemogenetically activating DMV also caused significant bradycardia with a correlated reduction in anxiety-like behavior. Thus, DMV contains uniquely hyperexcitable CVNs and is capable of cardioinhibition and robust anxiolysis.
