Stress and Appetite Linked

Link Between Stress and Appetite
Reported By Canadian Research
Scientists

Researchers in the Hotchkiss Brain Institute (HBI)
at the University of Calgary's Faculty of Medicine
have uncovered a mechanism by which stress increases food drive in laboratory subjects.

This new discovery, published online this week in
the journal Neuron, could provide important insight
into why stress is thought to be one of the under-
lying contributors to obesity.

Normally, the brain produces neurotransmitters (chemicals responsible
for how cells communicate in the brain) called endocannabinoids
that send signals to control appetite. In this study, the researchers
found that when food is not present, a stress response occurs that temporarily causes a functional re-wiring in the brain. This re-wiring
may impair the endo-cannabinoids' ability to regulate food intake and
could contribute to enhanced food drive.

The researchers also discovered that when they blocked the effects of stress hormones in the brain, the absence of food caused no change
in the neural circuitry.

Researchers looked specifically at nerve cells (neurons) in the region of
the brain called the hypothalamus. This structure is known to have an important role in the control of appetite and metabolism and has been identified as the primary region responsible for the brain's response to stress.

The team explains, "These findings could help explain how the cellular communication in our brains may be overridden in the absence of food. Interestingly, these changes are driven not necessarily by the lack of nutrients, but rather by the stress induced by the lack of food."

If similar changes occur in the human brain, these findings might have several implications for human health. "For example, if we elect to pass over a meal, the brain appears to simply increase the drive in pathways leading to increased appetite," explains the researchers. "Furthermore,
the fact that the lack of food causes activation of the stress response
might help explain the relationship between stress and obesity."

These results lay the foundation for future studies to investigate the use
of therapies that affect these systems in order to manipulate food intake. They also open the door to studies looking at whether or not the stress brought about by lack of food affects other systems where endo-cannabinoids are known to play a role.

"One thing we can say for sure, is that this research highlights the importance of food availability to our nervous system. The absence

of food clearly brings about dramatic changes in the way our neurons communicate with each other," they're emphasizing.

The research is supported by operating grants from the Canadian Institutes of Health Research (CIHR) and Alberta Innovates- Health Solutions (AI-HS).

Story Source:

University of Calgary (2011)
"Scientists highlight link between stress and appetite."

Journal Reference: "Endo-cannabinoids Gate State-Dependent Plasticity of Synaptic Inhibition in Feeding Circuits." Neuron Volume 71, Issue 3,

This article is for informational and educational purposes only, and is not intended to provide medical advice, diagnosis or treatment. Contact your doctor or healthcare professional for medical and nutritional consultation.