EFFECTS OF SURGICAL DECENTRALIZATION AND NERVE GROWTH FACTOR ON THE MATURATION OF ADRENERGIC NEURONS IN A MOUSE SYMPATHETIC GANGLION

Abstract— The increase in tyrosine hydroxylase activity in mouse superior cervical ganglion during postnatal development was prevented by administration of the protein synthesis inhibitor cycloheximide. Surgical section of the preganglionic nerves in 4-day-old mice prevented the normal increases in tyrosine hydroxylase and monoamine oxidase activity in the ganglion during development. Surgical decentralization also prevented the developmental increases in ganglion size and cell numbers. The preganglionic fibres thus appear to exert a general regulatory effect on the growth and biochemical maturation of postganglionic adrenergic neurons in sympathetic ganglia. Administration of nerve growth factor to young mice failed to eliminate the differences in ganglion size, cell numbers and tyrosine hydroxylase activity between normally innervated and decentralized ganglia. Nerve growth factor, however, caused an increase in all these parameters in both control and decentralized ganglia–the magnitude of these increases being greatest in the control ganglia. Administration of carbachol and physostigmine to neonatal mice did not influence the normal development of tyrosine hydroxylase activity in the superior cervical ganglion.