Supraoptic Neurosecretory Neurons of the Guinea Pig in Organ Culture. Biosynthesis of Vasopressin and Neurophysin

Fragments of the anterior hypothalamus that contain supraoptic nuclei and short axonal segments from adult guinea pigs have been kept in organ culture for up to 15 days. Electron micrographs displayed intact nuclei, Nissl substance, Golgi bodies, and an ultrastructure characteristic of viable neurosecretory cells; by contrast, the surrounding neurophil showed extensive degeneration. The cultured hypothalamic tissues of the guinea pig that were pulsed with [(3)H]uridine incorporated label into the RNA of neurosecretory neurons, as determined by radioautography and chemical analysis. Furthermore, and most important, these cells retained a complement of hormones and the ability to incorporate (3)H- and (35)S-labeled amino acids into vasopressin, neurophysin, and other polypeptides. This incorporation was inhibited by either puromycin or cycloheximide.