What if the future treatment of obesity took form as an X-ray beam to the head? After all, appetite control is regulated by the brain, specifically the hypothalamus. A new study published in Nature Neuroscience explored new nerve cell production stimulated by a high fat diet in mice.
This would not be as unexpected if cells were produced in other organs, but in the brain, it is remarkable. With a few exceptions, the adult brain does not make new nerve cells.
In the study, the mice were given a diet with a 60 percent fat content. Usually, mice are given a diet of 33 percent fat content to prevent them from weight gain. After consuming a fatty rich diet for several weeks, the researchers noticed the neurons in the hypothalamus had quadrupled when no changes were seen in the mice that were given a normal diet. This was detected by a c-fos molecular marker.
A high fat diet changed the brain circuitry in controlling hunger as well as the addition of many neurons. The researchers found the new neurons were descendants of glial cells called tanycytes. They were found on the median eminence which is located on the inferior boundary on the hypothalamus.
To test if the tanycytes were correlated to a high fat diet, the researchers targeted the newborn neurons for elimination by a beam of radiation to the hypothalamus. This is similar to using radiation therapy to kill cancer cells that are rapidly dividing. The radiation cleaves the DNA of the cell while they are in the process of dividing, thus other neurons in the hypothalamus that are not dividing were secured while the tanycytes were obliterated. As a result, the adult mice gained less weight as well as had increased energy levels compared to the fat rich diet mice that did not have their neurons irradiated.
There is no evidence that an increased fat diet increases tanycyte production in humans or other animals, but this study shows insight of how the brain can remodel in the presence of more fat. Obesity is a serious health problem in America that will not go away anytime soon. A study like this offers possible new therapies to target fat in places other than the digestive system and stomach by targeting fat in the organ that controls our hunger.
— Saha is a junior in neurobiology from Overland Park.