RESUMEN
Mongolian gerbil has been as an model animal for studing the neurological diseases such as stroke and epilepsy because of the congenital incompleteries in Willis circle, as well as the investigation of water metabolism because of the long time-survival in the condition of water-deprived desert condition, compared with other animal species. In order to accomplish this research, first of all another divided the laboratory animals 5 groups of which each group include the 5 animals. In this study of the long term water deprived condition author investigatied the vasopressinergic and oxytocinergic magnocellular neurons of the hypothalamus by using a quantitative immunohistochemistry, measured the plasma osmolalities at the time of sacrifice of indivisual animals, and the body weights every day during water-deprived. The results obtained in this study were summarized as followings: 1. The body weights and decreasing rates of the body weight in water-deprived animal groups were continuosly decreased. 2. The plasma osmolalities were increased from the 5th water-deprived day, after then the gradually increase reached nearly its equilibrium state at the 10th water-deprived day. 3. Vasopressin and oxytocin immunoreactive cells were mainly observed in PVN, SON and a few in the lateral magnocellular area of hypothalamus. 4. The number of VP immunoreactive cells in paraventricular and supraoptic nucleus were abruptly decreas-ed until the 5th day in the supraoptic nucleus in number and until the 10th day in the paraventricular nucleus of water-deprived. 5. The OT secreting cells were severely decreased on the 5th water deprived day in paraventricular and supraoptic nucleus, after than these cells were very slowly decreased until to the 38th water deprived day.