THE EFFECT OF LONG PERIODS OF CONTINUOUS HYDRATION ON THE NEUROSECRETORY MATERIAL IN THE HYPOTHALMUS OF THE DOG

Abstract

SUMMARY Dogs were kept in a state of excessive hydration by the oral administration of water, or its infusion into the stomach, for periods varying from 3 hr to 10 days. The effect of this procedure on the stainable neurosecretory material (NSM) in the hypothalamus was determined by histological examination. At the end of the longer periods of hydration there was seen an accumulation of NSM in the descending tracts from the paraventricular and supraoptic nuclei. In the 10-day hydrated animal a high proportion of the cell-bodies in these nuclei were depleted of NSM. The staining properties of the pars nervosa did not differ from normal. The hydrated animals exhibited large numbers of vesiculated neurones in the hypothalamic neurohypophysial nuclei.