Topography and numerical distribution of intracardiac ganglion cells in the cat

Serial sections stained with thionin and with phosphotungstic acid hematoxylin of a complete kitten heart and of portions of hearts from eight adult cats were studied to determine the location of intracardiac ganglion cells and to estimate their number. Ganglion cells were found in well defined anatomical relationships to the great vessels, the atria and the interatrial septum, but were never found below the coronary sulcus. Several distinct groups are described. The estimated total number of ganglion cells in an adult heart is 8405. Histological relationships between ganglion cell groups and nodal tissue, coronary arteries and myocardial tissue are described.