Why was this study done?

It has long been thought that thirst and dehydration sensations are regulated by plasma osmolality (concentration of electrolytes). This study was designed to help understand the mechanisms underlying thirst.

What did the study find?

That the act of drinking produces a neural response (through  a hormone called norepinephrine) that alerts the body’s thirst receptors and that thirst is not altered by the concentration of electrolytes in a solution.

Drinking-induced plasma vasopressin and norepinephrine changes in dehydrated humans
Authors: Geelen G, Greenleaf JE, Keil LC. J Clin Endocrinol Metab. 1996 Jun;81(6):2131-5.
PubMed Citation PMID: 8964840.
PDF Manuscript: J Clin Endocrinol Metab, 1996.