Notably, in the setting of high-frequency and prolonged sympathetic activation such as during acute myocardial ischemia, additional sympathetic co-transmitters other than norepinephrine (NE) are co-released from sympathetic post-ganglionic efferent fibers, including ATP, galanin and neuropeptide Y (NPY) (Herring 2015). This evidence concerns the gene NPY and myocardial ischemia.