Researchers from McGill University have made a discovery on how the brain detects and prevent dehydration. They identified a key protein in the brain responsible for body temperature as well as hydration. The findings can assist in clinical treatments of conditions that affect the imbalance of bodily fluids.
Study lead, Dr. Charles Bourque, said, “We have identified what we think is the first protein that could allow the brain to monitor physiological temperature and it is important because this protein contributes to how the brain detects heat and triggers adaptive responses such as thirst. This protein, which is an ion channel, that regulates the flow of ions across the cell membrane, is thought to play a crucial role in balancing body fluids (water, blood, etc.) and sodium (salts) levels, and changes in its regulation could be involved in linking salt to hypertension, and provoking fluid retention following cardiac failure, sepsis or brain trauma.”
The researchers investigated how the brain is able to control the salt and water balance in our bodies. The balance is detrimental to our health and if it is disturbed, it can have serious health consequences, such as high blood pressure or kidney damage.
The researchers pointed out that bodily fluid imbalances are commonly seen in emergency rooms. For example, a condition called hyponatremia often requires a trip the ER because the body’s sodium levels become low and water levels rise, which causes damage to cells and can result in side effects such as nausea and vomiting.
First author, Dr. Cristian Zaelzer, said, “Now that we have discovered the protein’s structure, we can try to understand how this ion channel is involved in conditions such as hyponatremia. This would give us tools to modify the channel’s mechanism of action and either prevent or treat the condition.”
Co-author, Dr. Wolfgang Liedtke, said, “Collaborating with Dr. Bourque’s group led to identification of a long sought-after TRPV1 ion channel that functions in neurons, making them sense osmotic pressure and temperature. This ion channel becomes active during dehydration, switching on the neurons in a part of the brain called the hypothalamus, which instructs the body to act in order to maintain its fluid balance. This can be achieved by triggering a sense of thirst, and also by the secretion of vasopressin – an antidiuretic hormone that acts to promote the retention of water by the kidneys – to maintain body fluid balance.”
Dr. Bourque concluded, “Interestingly, our work also shows that the ion channel is an alternate product of the gene TRPV1 that normally codes for the capsaicin receptor that detects “hot” chili peppers. It is like nature has engineered a salt receptor out of a pepper receptor.”
The findings were published in Cell Reports.