EFFECTS ON INGESTION AND EXCRETION OF WATER OF LESIONS IN A SINGLE HYPOTHALAMIC AREA

Water intake and urine output on a water loading test were studied in 81 albino rats before and after bilateral stereotaxically placed lesions to a wide variety of subcortical regions. Cessation or marked reduction of water ingestion followed lesions in the lateral hypothalamus. Diminished water output was found as an accompaniment to subcortical lesions in all regions studied save the internal capsule and globus pallidus, where slight increases in postoperative output were noted. In the posterior portion of the lateral hypothalamus, the lesions causing adipsia were accompanied by an increased output of urine. In a second experiment three additional animals were studied while being maintained in metabolism cages before and after lesions to this portion of the lateral region, and their water intake and urine output were compared with control animals receiving water and food restriction matched to that of the operated group. The findings of the first study were verified; the rats with lesions in the posterior lateral hypothalamic region were rendered adipsic, but their urinary output increased and became more dilute. © 1969.