Restoring the Autonomic Balance in an Atrial Fibrillation Rat Model by Electroacupuncture at the Neiguan Point

Autonomic nervous activity imbalance plays an important role in atrial fibrillation (AF). AF can be treated by acupuncture at the Neiguan point (PC6), but the mechanism remains elusive. Here, we investigated autonomic nervous system activity in electroacupuncture (EA) at PC6 in a rat AF model.

In this study, we established a rat AF model via tail vein injection with ACh-CaCl₂ for ten consecutive days with or without EA at PC6. AF inducibility and heart rate variability (HRV) were assessed by electrocardiogram. Next, we completed in vivo recording of the activity of cervical sympathetic and vagal nerves, respectively. Finally, the activities of brain regions related to autonomic nerve regulation were assessed by c-Fos immunofluorescence and multichannel recording.

EA at PC6 decreased AF inducibility and prevented changes in HRV caused by ACh-CaCl₂ injection. Meanwhile, EA at PC6 reversed the increased sympathetic and decreased vagal nerve activity in AF rats. Furthermore, EA treatment downregulated increased c-Fos expression in brain regions, including paraventricular nucleus, rostral ventrolateral medulla, and dorsal motor nucleus of the vagus in AF, while c-Fos expression in nucleus ambiguus was upregulated with EA.

The protective effect of EA at PC6 on AF is associated with balance between sympathetic and vagal nerve activities.