Atrial sympathetic and parasympathetic nerve sprouting and hyperinnervation induced by subthreshold electrical stimulation of the left stellate ganglion in normal dogs.
BACKGROUND
Subthreshold electrical stimulation of the left stellate ganglion (LSG) can induce nerve sprouting and sympathetic hyperinnervation in canine ventricles. It is unclear whether a similar neural plasticity involving both sympathetic and parasympathetic innervation also exists in the atria.


RESULTS
We applied subthreshold electrical stimulation at 20 Hz (0.45 ms pulse width) or 5 Hz (1.9 ms pulse width) to the LSG in 6 normal mongrel dogs. After 41+/-9 days, the hearts were harvested and the right and left atrium stained for synaptophysin (SYN), growth-associated protein 43 (GAP43), sympathetic nerve markers tyrosine hydroxylase (TH), and parasympathetic marker choline acetyltransferase (ChAT). Tissues from 6 additional healthy dogs were used as controls. The hearts from dogs with LSG electrical stimulation had a higher density of nerve structures immunopositive to the SYN, GAP43, TH, and ChAT (P<.01) in both right and left atria. Nerve density was equal in right and left atria. There were more TH-positive nerve structures than ChAT-positive nerve structures (P<.01) for both right and left atria. No atrial arrhythmia was observed at the second surgery.


CONCLUSIONS
Continuous subthreshold electrical stimulation to the LSG induces both sympathetic and parasympathetic hyperinnervation in both right and left atria in normal dogs.
Swissa
Moshe
M
Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center Los Angeles, CA 90027, USA.
Zhou
Shengmei
S
Tan
Alex Y
AY
Fishbein
Michael C
MC
Chen
Peng-Sheng
PS
Chen
Lan S
LS
D000320:Adrenergic Fibers / Q000378:metabolism*; D000818:Animals; D002795:Choline O-Acetyltransferase / Q000096:biosynthesis; D004285:Dogs; D004558:Electric Stimulation; D019922:GAP-43 Protein / Q000096:biosynthesis; D006325:Heart Atria / Q000294:innervation*; D007150:Immunohistochemistry; D009473:Neuronal Plasticity / Q000502:physiology*; D017777:Parasympathetic Fibers, Postganglionic / Q000378:metabolism*; D013233:Stellate Ganglion / Q000502:physiology*; D016708:Synaptophysin / Q000096:biosynthesis; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis
D019922:GAP-43 Protein; D016708:Synaptophysin; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase