Cardiac Regenerative Potential of Spiny Mice (Acomys cahirinus) Manifests Itself in Expansion of Pacemaker Myocardium and Predominance of Noncanonical, IK, ACH-Independent Pathway of Cholinergic Regulation in Cardiac Pacemaking

Spiny mice (Acomys cahirinus) exhibit the ability to regenerate the damaged myocardium and functional indices of the heart. demonstrated in various models of cardiac pathologies. Cardioregenerative potential of Acomys is associated with partial preservation of the neonatal phenotype of cardiac tissue in adult animals. The electrophysiology and mechanisms regulating the heart rhythm in Acomys are extremely poorly understood. The EEG was recorded in vivo and bioelectrical activity of the supraventricular myocardium was evaluated and mapped in spiny mice. Pacemaker-type action potentials were detected in a significant part of the right atrium, and primary activation involved approximately 41% of the atrium surface in Acomys. Cholinergic stimulation caused pronounced suppression of automaticity and changed the activation pattern of the pacemaker myocardium. IKAch-independent mechanisms mediated the cholinergic inhibition of automaticity in Acomys. Thus, the cardioregenerative potential of spiny mice manifests itself in delocalization and nonclassical regulation of the cardiac pacemaker.