Abstract
Cardiac performance is regulated by input of sympathetic nervous system. Junctions between sympathetic ganglion neurons (SGN) and cardiac myocytes are unique cell-cell contacts designed for the efficient regulation of heart rate and contractility by the autonomic nervous system. In the present study, we report that scaffold protein ankyrin G is localized to the postsynaptic sites in co-culture of cardiac myocytes and SGN. Consistent with roles of ankyrin G in targeting Nav channels to excitable domains in neurons and cardiac myocytes, we observed increased density of Nav channels at the neuro-cardiac junctions in co-cultures of cardiac myocytes and SGN. We also have found that KCNQ1 channels are present in increased density at the specialized zones of contacts of cardiac myocytes and SGN. An increased density of Nav and KCNQ1 channels at the neuro-cardiac sympathetic junctions may have an important role in modulation of cardiac action potential by neuronal input.