Innervation patterns of the middle cervical--stellate ganglion complex in the rat

The present experiments were designed to clarify the distribution of innervation of the middle and inferior cervical ganglia in the rat (middle cervical-stellate ganglion complex), the sympathetic ganglia which give rise to virtually all cardiac sympathetic nerves. Seven or 28 days after middle cervical-stellate ganglionectomy (surgical sympathectomy) norepinephrine content was measured in 9 peripheral areas including both the left and right atria and ventricles of the heart. The results were also compared to chemical sympathectomy produced with 6-hydroxydopamine. Seven or 28 days after surgical sympathectomy norepinephrine concentrations were reduced in all cardiac regions by at least 94%. Norepinephrine concentration in sub-diaphragmatic (spleen), but not supra-diaphragmatic (left intrascapular fat, left forelimb muscle), non-cardiac organs was preserved at control levels. 6-Hydroxydopamine treatment significantly reduced the norepinephrine concentration in all of the cardiac and non-cardiac tissues. The present evidence indicates that the middle cervical-stellate ganglion complex in the rat projects to a rather limited number of peripheral organs. Additionally, surgical sympathectomy produces more selective cardiac sympathectomy than 6-hydroxydopamine.