What is thirst? | Wired
“There are only a few things that are very important to your body that if you fall in a shortage, there is a completely inherent drive,” Knight said. “Oxygen, food, water and sodium.”
However, animals like us do not experience salt as a powerful and controlling stimulus such as oxygen, food and water. The sensors show the level of salt to the brain. In addition to OVLT and SFO, the sensors in the heart detect the atrium stretch and ventricle. But if needed, there is no similar salt, a way that the stomach cry for food or sore throat for water. Instead, the need to consume salt is mediated with taste and reward reward paths. “The taste of the salt is binary,” Knight said. “It has good taste in low doses; in high doses it disgusts, such as drinking seawater.”
Imagine insisting on eating a large bag of potato chips. If the body needs salt, these chips increase the enjoyable dopamine for the brain. If the body does not require salt, that dopamine drop will disappear. “This learning is very booster,” said Yuki Oka, a neurologist at the California Institute of Technology, who studies how to maintain the body of homeostasis. ” “Most dopamine means a frequent behavior.”
All thirst are different
Scientists collect data monitoring and then have a choice of whether they should act on their findings. Similarly, just because the brain measures the level of sodium blood, it does not mean that it has to act on it.
Take the Elena Grachova Thirteen Earth squirrels. Grachwa, a neurofiologist at Yale Medical School, studies native native North American meadows to find out how specific areas of the brain control thirst. He said the thirteen -underground squirrel is an ideal pattern for this, because more than half a year, without eating or drinking, it gets hibernation. “They’re like monks,” Grachwa said. “They don’t go out for eight months. They have no water in their underground.” How do they become thirsty?
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It’s not that squirrels do not need water. They do their body for it. But according to Grachwa research, their brains ignore the signals of the body during hibernation.
In mammals, blood water levels (which means increased salt concentration, everything is equal) causes two processes to be accompanied. The hypothalamus pumps vasopressin hormone, which tells the kidneys to preserve water instead of driving it as urine, and SFO moves from thirst to direct the animal to drink. However, while the ground squirrels are hibernating, their vasopressin levels jump, but the animal still does not drink. “Vasopressin circuit was normal, but thirst neurons were regulated,” Grachwa said. “These two paths are useless.” The body is trying to maintain its water but does not work for more consumption.
The logic of the disrupted circuit is very powerful. “Even if you wake them up in the middle of the hibernation, they don’t intend to drink,” Grachwa said.
The basic network that is Grachova’s studies in squirrels in global mammals, including humans, is universal. But the same neural logic does not lead to the same behaviors. Man drinks a glass of water during thirsty. Cats and rabbits get more water than they eat. Camels can burn their fat stores for water (which causes carbon dioxide and water), but gallons also consume and store it in their stomach because they need it later. Sea cavities can drink ocean water and repel the urine that is swimming from the water. They are the only marine mammals that actively do this.
How to manage each animal of water and salt in its ecosystem, lifestyle and chosen pressures. This question “What is the thirsty?” No one has the answer. We each thirst for their own way.
The main story is published under the authorization of Quanta Magazine, an independent publication of the Simmons Foundation, whose mission is to reinforce the general understanding of science by covering research developments, mathematics and physical sciences and life.
