New research sheds light on the mechanism that makes it possible for the brain to detect and prevent dehydration by making one thirsty.
In a study published on Oct. 6 in the journal Cell Reports, scientists from the McGill University Health Center and Duke University probed the structure of a key protein found in the human brain that regulates hydration and temperature.
This protein can be targeted to develop diagnoses and treatments for health issues linked to fluid imbalance in the body, which can lead to emergency situations in hospitals.
The protein, an ion channel, is believed to make balancing body fluids and salt levels possible.
“[C]hanges in its regulation could be involved in linking salt to hypertension” as well as prompting fluid retention after cardiac failure, sepsis or brain trauma, said lead author and McGill University medicine faculty Dr. Charles Bourque.
He also noted that they identified the first protein that allows the brain to monitor temperature and detect triggers such as thirst and other adaptive responses.
The team also analyzed (PDF) the process behind the brain’s control of osmoregulation, the process that maintains the balance of salt and water across membranes in bodily fluids. It warned against elevated salt levels that lead to kidney damage and high blood pressure.
This protein structure is investigated for its role in complications such as hyponatremia, a condition that occurs when there is abnormally low sodium levels in the blood, resulting in cognitive problems and seizures.
In 2006, Dr. Bourque’s team found that a gene known as TRPV1 played an important role in identifying changes in fluid balance in the body. Two years later, researchers discovered that the exact gene was part of the detection of body temperature, although the protein coming from this gene was still unknown.
According to senior co-author and Duke University professor Dr. Wolfgang Liedtke, this research allowed them to identify a TRPV1 ion channel functioning in neurons and making them detect osmotic pressure and temperature.
The said ion channel activates during dehydration and switches on neurons in the hypothalamus, the part of the brain signaling the body to respond favorably in maintaining fluid balance. This is made possible by thirst and the secretion of vasopressin, a hormone that promotes water retention in the kidneys.
“[T]he ion channel is an alternate product of the gene TRPV1 that normally codes for the capsaicin receptor that detects ‘hot’’ chili peppers,” added Dr. Bourque.
Photo: Allan Ajifo | Flickr