A pinboard by
Garron Dodd

Postdoc, Monash University


Specialised neurons in the brain turn 'on' our bodies thermostat to protect us from obesity.

As a nation, we are getting increasingly fat. Yet everyone knows someone who stays thin no matter how much they eat. Some people seem resistant to becoming overweight – but why? The answer to this could help prevent obesity, a disease that has become so prevalent that it is crippling world health systems. While much obesity research has concentrated on diet and exercise, I am interested in how our brains control fat cells. It turns out that people who don’t gain weight have more of a newly discovered type of fat cell called “beige fat”. Unlike traditional white fat cells, which store energy, beige fat cells burn fat, making us lose weight. People who are lean or exercise have far more beige fat cells than people who are obese, meaning they naturally burn more energy. So, is it possible to increase beige fat to prevent obesity? I have discovered that a specialised population of neurons in the brain instructs the body to produce more beige fat. These ‘fat burning’ neurons reside in a specialised region of the brain called the arcuate nucleus of the hypothalamus. Unlike other neurons in the brain, neurons in the arcuate nucleus are capable of directly sensing the levels of metabolic signals in the blood like the hormone insulin. As insulin is secreted by the pancreases after we eat, these specialised neurons have a unique insight in how much we have eaten and how much fat we have stored. With this information, these neurons are instrumental in turning ‘on’ our beige fat to protect us from weight gain and obesity. This system is really important because in obesity we have found that these neurons become resistant to insulin. This means that the brain can no longer turn ‘on’ our beige fat and help us lose weight! It seems that in obesity our brains become weird against us making it almost impossible to shed excess weight by diet and exercise alone. What we find is that by artificially stimulating these neurons in obese mice, we can turn beige fat back on and the mice lose weight. This breakthrough opens new avenues for treating obesity, with potentially revolutionary outcomes in terms of health and health spending.