Organ culture of rat superior cervical ganglia

The maintenance of adrenergic function has been investigated in organ cultures of adult rat superior cervical ganglia. Tyrosine hydroxylase and monoamine oxidase activities decreased gradually through 72 hours of culture. Dopamine beta-hydroxylase activity gradually increased in the cultured ganglia to 150% of that seen in fresh ganglia after 14 hours in culture. The level of norepinephrine increased in the cultured ganglia to a maximum of 225% of that seen in control ganglia. The increases in both dopamine beta-hydroxylase activity and in norepinephrine levels required protein synthesis but they were not dependent on the presence of nerve growth factor. The accumulation of norepinephrine in the cultured ganglia could not be explained by an increased rate of amine synthesis. Turnover measurements suggest that the accumulation can be explained by a decreased rate of amine metabolism in the cultured ganglia. A comparison of the distribution of amine storage vesicles showed that the number of heavy vesicles was greater in cultured than in fresh ganglia. The results suggest that sympathetic ganglia develop an increased capacity for amine storage in culture and that this leads to an increase in intracellular levels of norepinephrine.