Understanding Obesity and Overeating

A cluster of neurons in the brain may be driving excessive eating, says A*STAR’s Dr Sarah Luo, who won a Young Scientist Award for her research.

Dr Sarah Luo and her team from A*STAR made a discovery that could one day change how we view diabetes and obesity.


Why are some people prone to overeating, including those who are suffering from certain neurodegenerative diseases like Huntington’s disease? Dr Sarah Luo’s research on a group of neurons at the base of the brain, called the tuberal nucleus, may shed light on that.


When Dr Luo, a Principal Investigator in the Agency for Science, Technology and Research’s (A*STAR) Institute of Molecular and Cell Biology, and her team activated the tuberal nucleus in mice, they started to eat, and eat more than usual, even though they were not hungry.


She also discovered another peculiar effect. The mice were put in chambers for the feeding experiments. “After we activated the tuberal nucleus repeatedly, just putting the mice in the chambers somehow triggered them to eat, even when we hadn’t activated the neurons.”


One of her colleagues subsequently found a link between the brain’s memory centre and the nucleus. This means that the mice may have associated the chamber with eating after repeated activation of the nucleus, spurring them to eat more just by being in the chamber.


Dr Luo noted that her findings could change how we view diabetes and obesity. “Many times, when people are overweight or diabetic, others think they don’t have enough willpower to control their appetite. Our work suggests that, sometimes, could be environment triggers interacting with changes in the brain that leads people to eat more,” said the 35-year-old.


Her work is part of A*STAR’s Brain-Body Initiative, using multiomics approaches and advanced imaging to identify critical neural circuits, as well as uncovering their contributions to metabolic regulation and feeding behaviour.


Dr Luo won a Young Scientist Award at the 2021 President’s Science and Technology Awards for her research. “I am grateful for the validation. I think it also highlights that metabolic disorders, obesity and diabetes are pressing health and societal issues that need to be solved.”


Her current research aims to identify peripheral neural circuits – neurons located in the body outside of the brain – that send appetite-related signals to the brain. She explained that these would be easier to target than neurons in the brain, to treat harmful eating behaviours.


She is also investigating the tuberal nucleus’s link to eating abnormalities and metabolic conditions that often accompany some neurogenerative diseases. “People with Huntington’s disease, for example, tend to consume a lot more food. You also often see Parkinson’s disease patients who are obese, and obesity may increase the prevalence of Parkinson’s disease.”


Dr Luo and her team are investigating the tuberal nucleus’s link to eating abnormalities and metabolic conditions that often accompany some neurogenerative diseases.


Dr Luo said that Singapore’s strong support for scientists has been crucial to her career. Her undergraduate and PhD studies in the United States were supported by an A*STAR National Science Scholarship, and she set up her own laboratory last year with the help of a National Research Foundation Fellowship.


Mentors and colleagues have given her valuable advice, and she has given back by training and mentoring others.


She said: “All scientists know that it is impossible to go through this journey by yourself. In Singapore’s research ecosystem, there are so many opportunities for young scientists.”


About the A*STAR National Science Scholarship


The A*STAR National Science Scholarship (PhD) is awarded to outstanding individuals who wish to pursue a rewarding career in research. Successful applicants will be fully-funded for their academic pursuits, which will commence after they have completed one year of paid research attachment at an A*STAR Research Institute.


Find out more here.


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