Copyright information:Taken from "NADPH- Diaphorase positive cardiac neurons in the atria of mice. A morphoquantitative study"BMC Neuroscience 2006;7():10-10.Published online 2 Feb 2006PMCID:PMC1373636.Copyright © 2006 Maifrino et al; licensee BioMed Central Ltd. The neurons are represented by dots. La= left atrium; Ra = right atrium; Pv = pulmonary veins; Svc = superior vena cava; Ivc = inferior vena cava; Lv = left ventricle; Rv = right ventricle. Calibration bar: 0.1 mm.