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

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. Adult male Sprague Dawley rat brainstem 10 µm sections evenly spaced 200 µm apart were put on 2 Visium slides (8 sections total). Permeabilization, barcoding, library construction, and sequencing were performed for each 50 µm barcoded spot. We did this throughout the extent of the brainstem including the DMV at the level of Area Postrema.