A spinal transcommissural connection for symmetrical sympathetic reflex response. Intra-axonal tracing study in the rat.

Wheatgerm agglutinin conjugated horseradish peroxidase was injected into the ganglion cervicale superior of the sympathetic trunk of seven adult rats. Labelled neurons were found in the ipsilateral anterior commissural nucleus of the spinal cord at the C1 level. Transcommissural crossing of labelled fibres and symmetrical labelling of neurons in the contralateral nucleus were also found. Labelled fibres could then be followed contralaterally into the superior cervical ganglion where labelled neurons were also found.