Retrograde Changes in the Nervous System Following Unilateral Sympathectomy

In consequence of right-sided smpathectomy at the level of C5 it was found that in the sheep the cervical sympathetic trunk contains nerve fibres which proceed from cells situated in the first four segments of the thoracic part of the spinal cord and in the stellate ganglion. These fibres are about 85 per cent of all fibres of the sympathetic trunk. The remaining 15 per cent proceed from nerve cells situated nasally of the anterior cervical ganglion.
http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0442.1967.tb00255.x/abstract