Scientists have developed a new technique to monitor the area of the brain that regulates hunger.
Using magnetic resonance imaging on mice, scientists detected increased neuron activity when the mouse was hungry, which made the scan 'light up'.
The researchers were able to observe how the neurons reacted to different stimuli.
It is hoped the study will lead to a better understanding of obesity.
Lead author Professor Jimmy Bell, from the MRC Clinical Sciences Centre at Imperial College London, said previous studies had relied on the subjective measure of asking people how hungry they were.
"Our new method is much more reliable and completely objective. With marine models, we can now look directly at neuronal activity in the brain. We are working on developing similar methods to study neuronal activity in the appetite centres in people."
The report is published today in the Journal of Neuroscience.
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