Homeostatic regulation of cardiac function is dependent on the balance of inputs from the
sympathetic and parasympathetic nervous systems. We investigated whether the p75
neurotrophin receptor plays a developmental role in cardiac innervation by analyzing
sympathetic and parasympathetic fibers in the atria of p75 knockout and wildtype mice at
several stages of postnatal development, and examining the effect on control of heart rate.
We found that parasympathetic innervation of the atria in p75−/− mice was similar to wildtype …