In vivo tracing of the ascending vagal projections to the brain with manganese enhanced magnetic resonance imaging

Frontiers in Neuroscience

Neuroscience

Xiaokai Wang¹  Jiayue Cao¹  Zhongming Liu²  Steven Oleson³ 

[1] Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States;Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States;Department of Electrical Engineering Computer Science, University of Michigan, Ann Arbor, MI, United States;Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States;

关键词: manganese-enhanced magnetic resonance imaging;    neuronal tracing;    vagus nerve;    vagus nerve stimulation;    nucleus tractus solitarius;   

DOI  :  10.3389/fnins.2023.1254097

 received in 2023-07-06, accepted in 2023-08-31,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionThe vagus nerve, the primary neural pathway mediating brain-body interactions, plays an essential role in transmitting bodily signals to the brain. Despite its significance, our understanding of the detailed organization and functionality of vagal afferent projections remains incomplete.MethodsIn this study, we utilized manganese-enhanced magnetic resonance imaging (MEMRI) as a non-invasive and in vivo method for tracing vagal nerve projections to the brainstem and assessing their functional dependence on cervical vagus nerve stimulation (VNS). Manganese chloride solution was injected into the nodose ganglion of rats, and T1-weighted MRI scans were performed at both 12 and 24 h after the injection.ResultsOur findings reveal that vagal afferent neurons can uptake and transport manganese ions, serving as a surrogate for calcium ions, to the nucleus tractus solitarius (NTS) in the brainstem. In the absence of VNS, we observed significant contrast enhancements of around 19–24% in the NTS ipsilateral to the injection side. Application of VNS for 4 h further promoted nerve activity, leading to greater contrast enhancements of 40–43% in the NTS.DiscussionThese results demonstrate the potential of MEMRI for high-resolution, activity-dependent tracing of vagal afferents, providing a valuable tool for the structural and functional assessment of the vagus nerve and its influence on brain activity.

【 授权许可】

Unknown   
Copyright © 2023 Oleson, Cao, Wang and Liu.