A Comprehensive Integrated Anatomical and Molecular Atlas of Rodent Intrinsic Cardiac Nervous System

Abstract

In this study, we developed, coordinated, and integrated several technologies including novel whole organ imaging, software development to support the very first precise 3D neuroanatomical mapping and molecular phenotyping of the intracardiac nervous system (ICN). While qualitative and gross anatomical descriptions of the anatomy of the ICN have been presented, we here bring forth the first comprehensive atlas at large scale of the entire ICN in rat at a single cell resolution. Our work for the first time provides a novel 3D model to precisely integrate anatomical, functional and molecular data in the 3D digitally reconstructed whole heart with high resolution at the micron scale. This work represents the cutting edge in a long history of attempts to understand the anatomical substrate upon which the neuronal control of cardiac function is built. To our knowledge, there has not yet been a comprehensive histological mapping to generate a neurocardiac atlas at cellular and molecular level for the whole heart of any species. We now display the full extent and the position of neuronal clusters on the base and posterior left atrium, and the distribution of molecular phenotypes in that context. In addition we display in this context distinct molecular phenotypes that are defined along the base-to-apex axis, and the present novel discovery of their phenotypical spatial gradients, have not been previously described. The development of these approaches needed to acquire these data has produced method pipelines which can not only achieve the goals of anatomical and molecular mapping of the heart, but also provide the method pipelines for mapping other organs (e.g., stomach, lung, kidney, and liver).