Nerve growth factor and preganglionic cholinergic nerves; their relative importance to the development of the terminal adrenergic neuron

Summary To delineate the relative importance of nerve growth factor (NGF) and the activity of preganglionic cholinergic nerves for the development of the terminal adrenergic neuron we have studied the changes in growth and differentiation of the rat superior cervical ganglion and the changes in its response to NGF after dissection of the preganglionic cholinergic trunk. Decentralization of the left superior cervical ganglion was performed in 3-day-old Wistar rats of either sex. Two weeks later the choline acetyltransferase activity was determined as a measure of completeness of decentralization, the protein content as a measure of general growth and the specific activity (product formed/h/mg protein) of tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) asa measure of differentiation of the terminal adrenergic neuron. Choline acetyltransferase of the decentralized side was reduced to Decentralization did not impair the effect of NGF on general growth or the selective induction of TH and DBH. It is concluded that the main factor for growth and differentiation of the terminal adrenergic neuron is NGF, which does not depend on the intactness of the preganglionic cholinergic fibers. The activity of the latte seems to represent an additive factor only to the development of the adrenergic neuron.