Lying deep in the brain, an overlooked region controls feeding patterns in mice, neuroscientists at A*STAR have shown. This discovery opens up the possibility of developing new ways to treat eating disorders in humans.
Hunger is the brain’s way of telling us to eat. So far, several regions in the brain have been demonstrated to play a role in controlling appetite and other aspects of eating.
Now, Yu Fu of the Singapore Bioimaging Consortium and colleagues have found the mechanism is more complex than previously thought. They discovered that an unsuspected region — the tuberal nucleus, part of the hypothalamus — affects appetite in mice.
Fu was taken aback by the dearth of studies on the tuberal nucleus. “To my surprise, I found almost nothing in the literature on its function,” he recalls. His curiosity was piqued when he learned that patients with neurodegenerative conditions, such as Huntington’s disease, often exhibit both marked changes in appetite and variations in the tuberal nucleus.
To investigate a possible connection between the tuberal nucleus and appetite, Fu’s team induced hunger by depriving mice of food overnight. They found that this activated neurons in the tuberal nucleus that express somatostatin — a hormone that affects physiological functions and inhibits the production of otherhormones. The same thing happened when the team administered the ‘hunger hormone’, ghrelin.
To confirm this connection, the researchers artificially activated the neurons in the tuberal nucleus and found that the mice ate more than usual. And when they turned off the same neurons, the mice cut back on food.
There is a strong probability that these findings will carry over to humans. “It’s very likely that the same population of neurons in the human brain has a similar function,” Fu comments.
If that’s the case, it should allow neuroscientists to develop new strategies for treating obesity and eating disorders such as anorexia. The team is currently collaborating with other researchers to see if brain imaging reveals any changes in the tuberal nucleus and nearby regions in people with eating disorders.
The team is also keen to explore the relation between the various neural processes involved in feeding. “Several nuclei in the brain have been found to regulate feeding,” says Fu. “The obvious question is: why do animals need so many different neural clusters to regulate feeding?”
The A*STAR-affiliated researchers contributing to this research are from the Singapore Bioimaging Consortium.