Exercise Quadruples Right-Side Heart Nerve Neurons in Rats, Reshaping Left and Right Stellate Ganglia Differently
Updated
Updated · SciTechDaily · May 19
Exercise Quadruples Right-Side Heart Nerve Neurons in Rats, Reshaping Left and Right Stellate Ganglia Differently
1 articles · Updated · SciTechDaily · May 19
10 weeks of moderate treadmill exercise left rats with about four times more neurons in the right stellate ganglion than the left, revealing a sharply uneven rewrite of nerves that help control heart rate and blood pressure.
3D imaging also showed opposite structural shifts: left-side neurons grew about 1.8 times larger, right-side neurons became slightly smaller, and the overall ganglion volume shrank after training.
University of Bristol researchers said the findings challenge the assumption that exercise remodels the autonomic nervous system uniformly, instead pointing to distinct left-right adaptations in the heart’s sympathetic circuitry.
That asymmetry could matter because cardiologists already target stellate ganglia with nerve blocks or denervation for severe arrhythmias, hard-to-control angina and Takotsubo “broken-heart” syndrome.
The study was conducted in rats, so the team said human work is still needed; next they plan to test how the structural changes affect heart function and whether the same pattern appears in larger animals and people.
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Exercise-Induced Left-Right Differences in Heart Nerve Remodeling: Implications for Arrhythmia Treatment and Precision Cardiac Care
Overview
A 2025 study by University of Bristol researchers revealed that regular aerobic exercise causes the nerves controlling the heart to remodel in an asymmetric, side-specific way. This challenges the traditional belief that the nervous system adapts uniformly. The research found that neuroplasticity in the stellate ganglia—the nerve clusters regulating heart rhythm—differs between the left and right sides after exercise. These findings build on earlier work showing exercise-induced changes in heart nerves and suggest that moderate exercise can deeply reshape the neural architecture of cardiac control, opening new possibilities for targeted therapies and personalized heart care.