The influence of preganglionic nerves on the superior cervical ganglion of the rat.

Sympathetic neurones grown in tissue culture with non-neuronal cells become cholinergic. Such a change from an adrenergic to cholinergic character does not occur in vivo and it has been suggested that this may be due to the determination of the adrenergic character by electrical activity. Electrical activity in the superior cervical ganglion by young rats were prevented by transection of the preganglionic nerve trunk. In no case did this operation result in an increase in the intrinsic choline acetyltransferase (CAT) of the ganglion. We conclude that electrical activity is not the factor responsible for the difference between in vivo and in vitro results.