EFFECTS OF WATER DEPRIVATION UPON THE NEUROSECRETORY MATERIAL OF THE DESERT RAT (MERIONES MERIONES) COMPARED WITH THE LABORATORY RAT

Abstract

SUMMARY The effects of dehydration, brought about by water deprivation over a period of 10 days, upon the stainable neurosecretory material (NSM) of the hypothalamo-hypophysial system were compared in two species of rodents originating from different climatic habitats, namely the laboratory rat (Rattus norvegicus) and the desert rat (Meriones meriones). While the neural lobe of the laboratory rat was virtually completely depleted of NSM by this procedure, that of the desert rat showed no detectable histological changes. No striking changes were found in the hypothalamus of either species following this period of water deprivation, although there was some indication of disappearance of NSM from the hypothalamus in the desert rat. The results are briefly discussed in relation to the theory of hypothalamic neurosecretion.