April 5, 2013
Researchers Find Brain Cells That May Help Rewire Appetite Control
Alan McStravick for redOrbit.com - Your Universe Online
Until recently, scientists believed that the nerve cells in the brain associated with appetite regulation were generated entirely during embryonic development. This meant if you were pre-programmed for an eating disorder, the nerve cells were fixed for life.However, a team of researchers at the University of East Anglia (UEA) in the UK have made a breakthrough in the field of neurosciences which could offer a long-lasting solution to eating disorders such as obesity.
The team´s findings, published in the Journal of Neuroscience, have located a population of stem cells in their rodent subjects that are actually capable of generating new appetite-regulating neurons in the brain.
The researchers believe their findings could provide far reaching benefits to the growing number of individuals dealing with obesity. Globally, more than 1.4 billion adults are overweight. Of those, more than half a billion are obese. Obesity can lead to chronic health problems like heart disease, arthritis, type 2 diabetes and cancer. Mortality due to being overweight and obese exceeds 2.8 million people each year.
And the numbers above can be translated into economic burdens on national healthcare systems and economies. Illness and disease due to excessive weight tops $60 billion annually in the US alone.
To arrive at their findings, the UEA scientists focused on the brain´s hypothalamus, which is responsible for the regulation of sleep and wake cycles, energy expenditure, appetite, thirst, hormone release and many other critical biological functions. Within the hypothalamus, the researchers specifically studied the nerve cells responsible for appetite regulation.
To this end, the researchers employed a technique known as ℠genetic fate mapping´ which led them to their discovery. This technique tracks the development of stem cells and cells derived from them at desired time points throughout the animal´s life cycle.
What the team discovered was a population of brain cells called ℠tanycytes´ that behave much like stem cells. However, unlike stem cells they are capable of adding new neurons to the appetite-regulating circuitry of the mouse brain after birth and even into adulthood.
“Unlike dieting, translation of this discovery could eventually offer a permanent solution for tackling obesity,” said the study´s lead researcher Dr. Mohammad K. Hajihosseini of UEA´s school of Biological Sciences.
“Loss or malfunctioning of neurons in the hypothalamus is the prime cause of eating disorders such as obesity. Until recently, we thought that all of these nerve cells were generated during the embryonic period and so the circuitry that controls appetite was fixed,” Hajihosseine continued.
“But this study has shown that the neural circuitry that controls appetite is not fixed in number and could possibly be manipulated numerically to tackle eating disorders.”
Regarding future research in this field, he said: “The next step is to define the group of genes and cellular processes that regulate the behavior and activity of tanycytes. This information will further our understanding of brain stem cells and could be exploited to develop drugs that can modulate the number or functioning of appetite-regulating neurons.”
“Our long-term goal of course is to translate this work to humans, which could take up to five or 10 years. It could lead to a permanent intervention in infancy for those predisposed to obesity, or later in life as the disease becomes apparent.”