The innervation of the umbilical cord of the rat. A histochemical study.

The umbilical cords of 21 days old rat foetuses were investigated using histochemical methods for acetylcholinesterase and catecholamines. An AChE positive nerve plexus is situated only around the vitelline vessels. At regular intervals the bundles of this plexus exhibit small ganglia. These ganglia are made up of nerve cells, which are AChE positive and show formaldehyde induced fluorescence, thus indicating an adrenergic nature of these cells. No innervation could be found in the allantoic part of the umbilical cord.