Identification of neurophysin producing cells

Immuno-enzyme histochemical investigations on the bovine hypothalamus showed that the infundibular nucleus contains neurons that produce either neurophysin I or a neurophysin I-like substance. Fine processes of these neurons run in the direction of the median eminence. The possibility that these processes could be the origin of the "neurophysin I-oxytocin" containing nerve fibres of the external region of the median eminence is discussed.