Research seems to answer why people don’t get dehydrated while sleeping

Ever wondered why we don’t get dehydrated while sleeping? Well, the answer to this question apparently lies in a research. During the day, people adjust their water content by drinking. Nevertheless, since one does not drink water while they are sleeping, one has to minimize water loss so they don’t become dehydrated.

In some way, our bodies should ‘dial back’ the desire to drink and consequently our need to go visit the toilet. Charles Bourque and Eric Trudel, two neurophysiologists from the Centre for Research in Neuroscience at the Research Institute of the McGill University Health Centre (RI MUHC) and McGill University have apparently found how the body may move from its daytime hydration strategy to its noctural plan of water preservation.

Dr. Bourque commented, “The body prevents dehydration during the night by modifying the activity of three groups of brain cells. The cell groups work together to control fluid balance We already knew that water retention is regulated by a hormone released by the first group of cells, located in the hypothalamus. These cells are activated by a second group of cells which detect water level fluctuations. The third group of cells, also found in the hypothalamus, controls the body’s internal clock.”

When the ‘clock cells’ seem to decelerate in preparation for sleep, they apparently motivate the other two cell groups to communicate more actively. Consequently, additional vasopressin, a hormone that could enable the body preserve water is said to be discharged by the hypothalamus.

Eric Trudel, PhD student at the Centre for Research in Neuroscience, RI MUHC/McGill, remarked, “In effect, when the biological clock slows down, the body begins to enter its nocturnal mode and conserve water. Conversely, when the ‘clock cells’ speed up, the interaction between the water sensing and water retaining groups of cells weakens, and the body retains less water.”

Dr. Bourque mentioned that their future challenge is to investigate whether clock output controls other central circuits such as hunger or sleepiness in a similar manner.

The findings were published in Nature Neuroscience.