In a new study involving mice, scientists explored the effects of a high-fat diet on the brain cells controlling appetite. They discovered that as the mice ate more fatty foods and became obese, this triggered a reduction in the activity of the relevant nerve cells.
The Experimental Conditions
For the study, mice were fed with a rich high-fat diet for a period of two weeks. Their brain activity was monitoring during that time. Of particular interest to the researchers was the lateral hypothalamus region of the brain where control of many body functions occurs, including eating behavior. There are many diverse cells there.
In this study, the glutamatergic nerve cells were looked at because the gene behavior in these single cells was largely influenced by whether the mice were lean or obese. In some previous research work, it was suggested that glutamatergic cells behave like a brake on appetite, and when they are blocked from firing signals, mice tend to eat more food and gain weight. The more recent study was led by Garret Stuber, a neuroscientist at the University of Washington in Seattle. The results of the study are reported in the journal Science.
The researchers found that certain cells in the brains of the mice, which usually limit appetite at a certain point, were less active after the fatty binge for the mice in the study. For the control group of mice that were not fed on the same fatty food, the brain cells showed more activity. These findings show that a fatty diet triggers the mice to continue eating and removes the normal signal to stop eating after a meal.
Although the implications of the study’s findings are yet to be fully explored in mice and in humans, they are significant. Learning more about how the brain controls the appetite could prove useful in understanding human feeding and over-eating.