Scientists have identified a group of brain cells which have the power to control appetite and could be a major cause of eating disorders such as obesity.In experiments in rodents, cells called tanycytes were found to produce neurons which specifically regulate appetite.The University of East Anglia researchers say their find means appetite is not fixed at birth.Their study is published in the Journal of Neuroscience.It was previously thought that nerve cells in the brain associated with appetite regulation were generated entirely during an embryo's development in the womb and could not be altered.But the UEA study's discovery of these tanycytes, which act like stem cells, in the brains of young and adult rodents shows that appetite can be modified.Researchers looked in detail at the hypothalamus section of the brain, which is known to regulate sleep, energy expenditure, appetite, thirst and many other critical biological functions.They studied the nerve cells that regulate appetite using a 'genetic fate mapping' technique and found that some cells added neurons to the appetite-regulating circuitry of the mouse brain after birth and into adulthood.Circuit control Lead researcher Dr Mohammad Hajihosseini, from the university's school of biological sciences, said the discovery could eventually offer a permanent solution for tackling obesity - but it would take up to five or 10 years to translate the findings into humans."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."The next step is to define the group of genes and cellular processes that regulate the behaviour 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."Although there isn't one single solution to controlling appetite, Dr Hajihosseini says any sustained solution to obesity must focus on the part of the brain that makes decisions on appetite."This is adding another piece to the jigsaw."The research was funded by the Wellcome Trust.