What is thirst? | Wired
“There are only a few things that are so important for your body that there is a completely innate drive to get it if you fall into a shortage,” Knight said. “Oxygen, food, water and sodium.”
However, animals like us do not perceive salt desire as powerful, controlling driving as well as oxygen, food and water. Sensors signal the levels of salt in the brain; In addition to OVLT and SFO, sensors in the heart reveal stretching atric and ventricular. But there is no analog salt pango when we need, the way the stomach for food or scratches is cramped for water. Instead, the need to consume salt is mediated by tastes and brains of awards. “The taste of salt is bimodan,” Knight said. “It’s good taste in low doses; at high doses tastes disgusting, like drinking seawater.”
Imagine the urge to eat a large bag of potatoes chips. If the body needs salt, these chips will cause a pleasant dopamine to flood the brain. If the body doesn’t need salt, that dopamine drop disappears. “It is quite learning strengthening,” Yuki of the eye, neurobiologist at the California Institute of Technology that studies how the body maintains homeostasis. “More dopamine means repeated behavior.”
Everybody’s thirst is different
Scientists who follow the river collect data, and then have a choice whether to act on their findings. Similarly, only because the brain measures the blood of sodium does not mean that it has to act on that information.
Take thirteen trone squirrels Elena Grachev. Gracheva, neurophysiologist at Chinese school school, studies these rodents, originally with North American lawns, to understand how concrete regions of the brain control thirst. Thirteen lined ground squirrels is an ideal model for this, she said, because he hibernates for more than half a year, without eating or drinking. “They’re like a monk,” Grachev said. “They don’t go outside for eight months. They don’t have water in their underground burr.” How would they not thirst?
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It’s not that squirrels don’t need water. They do it. Their bodies cry for that. But according to Grac’s survey, their brain ignores the body signals during hibernation.
In mammals, a drop in blood water levels (which means the simultaneous increase in salt concentration, all things that are equal) run two related processes. The hypothalamus pump hormone vasopressin, which sends kidneys to keep water, not release it as urine, and SFO begins with a drinking thirst. However, while the ground squirrels are hized, their vasopresinal levels are jumping, but the animal still does not drink. “The vasopressine circuit was normal, but the thirst of neurons were regulated,” Grachev said. “These two tracks are unlit.” The body tries to keep the water it has, but it does not work would not be consumed more.
The logic of the disturbed circle is extremely powerful. “Even if you wake them up in the middle of hibernation, they won’t drink,” Grachev said.
In the basic network that Graheva studies in squirrels is universal in mammals, to and including people. But that same neurological logic does not lead to the same behaviors. People drink a glass of water when they are thirsty. Cats and rabbits generally lead water from the food they eat. Camels can burn their fatty water stores (which produce carbon dioxide and water), but they also consume gallons and keep it in the stomach when they need it later. Marine Vidri can drink ocean water and excrete urine that is solution from water they swim; They are the only sea mammals who are actively working.
As each animal manages water and salt specializes in its ecosystem, lifestyle and selective pressures. Question “What does it mean to be thirsty?” There is no one answer. Every thirst in your own way.
The original story for a re-written permission from Quanto Magazine, editorial independence of the Simons Foundation whose mission is to improve public understanding of science by attending the development of research and physical and life sciences.