Phenotypic screening for heart rate variability in the mouse

We developed a technology for heart rate (HR) variability (HRV) analysis in the mouse for characterization of HR dynamics, modulated by vagal and symp athetic activity. The mouse is the principal animal model for studying biol ogical processes. Mouse strains are now available harboring gene mutations providing fundamental insights into molecular mechanisms underlying cardiac electrical diseases. Future progress depends on enhanced understanding of these fundamental mechanisms and the implementation of methods for the func tional analysis of mouse cardiovascular physiology. By telemetric technique s, standard time and frequency-domain measures of HRV were computed with an d without autonomic blockade, and baroreflex sensitivity testing was perfor med. HR modulation in the high-frequency component is predominantly mediate d by the parasympathetic nervous system, whereas the low-frequency componen t is under the influence of both the parasympathetic and sympathetic system s. The presented technology and protocol allow for assessment of autonomic regulation of the murine HR. Phenotypic screening for HR regulation in mice will further enhance the value of the mouse as a model of heritable electr ophysiological human disease.