Do you often struggle with eating every time you are a tad bit stressed? The latest study may have the answer to this unusual behaviour. The team of scientists involved in the study discovered a neuro-circuit in mice that, when activated, increased their stress levels while decreasing their desire to eat. The study was published in the journal 'Nature Communications'.
According to the researchers, these findings may help efforts to develop treatments for serious eating disorders like anorexia nervosa, which has the highest mortality rate of any mental disorder, according to the National Institute of Mental Health. In anorexia nervosa, people develop a peculiar repulsion against food, they eat in very small quantities and only certain foods. They constantly see themselves as overweight, even if they are severely underweight.
"We have identified a part of the brain in a mouse model that controls the impact of emotions on eating," said Qingchun Tong, PhD, the study's senior author and an associate professor at the Center for Metabolic and Degenerative Disease at McGovern Medical School at UTHealth.
Since mice and humans have similar nervous systems, Tong, the Cullen Chair in Molecular Medicine at UTHealth, believes their findings could shed light on the part of the human brain that regulates hunger.
The study is among the first to demonstrate the role of this neurocircuit in the regulation of both stress and hunger, according to the investigators.
While previous research has established that stress can both reduce and increase a person's desire to eat, the neural mechanisms that act on the regulation of eating by stress-related responses largely remain a mystery.
Tong's team focused on a neurocircuit connecting two parts of the mouse brain: the paraventricular hypothalamus, an eating-related zone in the brain, and the ventral lateral septum, an emotional zone in the brain. The neurocircuit acts as an on/off switch.
When the neurocircuit was activated, there was an increase in anxiety levels and a decrease in appetite. Conversely, when the investigators inhibited the neurocircuit, anxiety levels dropped and hunger increased. The scientists used a research technique called optogenetics to turn the neurons in question on and off.
Yuanzhong Xu, PhD, the study's lead author and an instructor at McGovern Medical School, said additional preclinical tests are needed to investigate the link further.