A team of Johns Hopkins researchers have recently identified a brain ‘switch’ that may be responsible for controlling appetite in mice. If the switch is ‘broken,’ the rodents find it hard to stop eating and become obese in less than a month.
The team believes that blood sugar may influence when the switch is turned on after having a meal. When the switch is on people feel full, but when the switch is off or fails to work properly people tend to overeat.
Researchers discovered the new mechanism while they were analyzing the strength of neural connections in the brains of laboratory mice. They have long suspected that an enzyme dubbed OGT may have something to do with appetite control. So, they decided to genetically tweak several mice to block enzyme production in the rodents’ brain and see what happens.
Past studies had revealed that OGT also plays an important role in various metabolic processes such as insulin and blood glucose use. But when researchers removed the enzyme from mice’s brains, the animals put on weight rapidly. Some of them became obese in only about three weeks.
Olof Lagerlof, lead author of the study, noted that the animals cannot grasp when they had enough food so they keep gorging on. The team also found that appetite could no longer be controlled when the OGT enzyme lacked in a certain area of the brain in the hypothalamus.
Researchers reported that they noticed the mice were getting really fat two weeks after the experiment. Yet, the team wanted to confirm whether the OGT enzyme was responsible for appetite control. So, they artificially raised the levels of the enzyme in some mice’s brains. These mice stopped from eating even when they were still hungry.
Scientists also said that the mice that had the OGT removed from their systems lingered over their meals and ate twice as many calories as normal mice. Though the mice were not given extra portions, they kept putting on weight at an extremely fast rate.
The team explained that the enzyme acts like a switch that gets turned on or off by the levels of blood sugar which naturally increase after a meal.
Researchers suspect that a similar switch may be found in humans too. Yet, they need more research to confirm the hypothesis. If the theory is correct, however, scientists could develop drugs that can control appetite and prevent people from overeating.
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