That little voice inside your head that tells you to keep eating is , in fact , simply a cluster of around 10,000 brain cells . Now scientists believe they have found tiny triggers inside those cells that give rise to this 'voice ' and ruin a dieter 's good intentions . The new research , done on fish and mice , could someday lead to pills that will be able to quieten that voice or increase its volume . The research focused on POMC neurons , which are a structure called the hypothalamus , that send and receive signals to regulate appetite . On the left , images of normal hypothalamus POMC cells from a developing mouse . On the right : when the gene for the transcription factor is deleted , the cells no longer make it . The research focused on POMC neurons , which are a structure called the hypothalamus , that send and receive signals to regulate appetite . When POMC neurons are absent , or not working properly , animals and humans grow dangerously obese . The new findings show in animals that the same thing happens when certain genetic triggers inside the POMC cells are n't working . The team , led by the University of Michigan , looked at how a protein called a transcription factor , and two small stretches of DNA called enhancers , act as triggers for the Pomc gene . All three regulate how often and when the POMC cells use the gene to create the signal molecules that then go out to the body . That little voice inside your head that tells you to keep eating is , in fact , simply a cluster of around 10,000 brain cells . Now scientists believe they have found tiny triggers inside those cells that give rise to this 'voice ' 'The POMC region is a central node of the brain 's means for regulating body weight , in response to influences from the hormone leptin , ' said Malcom Low , a professor in the Department of Molecular and Integrative Physiology . Like signal lights that show pilots the path to an airport runway , enhancers guide proteins toward the gene so it can be read . Located deep inside the brain , in a structure called the hypothalamus , the cluster of POMC neurons act as a control center for feelings of fullness or hunger . They take in signals from the body , and send out chemical signals to regulate appetite and eating . When POMC neurons are absent , or not working correctly , animals and humans grow dangerously obese . The latest research show in animals that the same thing happens when certain genetic triggers inside the POMC cells are n't working . The researchers found that the two enhancers act in ways that complement one another , both encouraging the expression of the Pomc gene at key times . Mice born without both of them became obese – as if their Pomc gene had been deactivated . The protein that latches on to the enhancer , called a transcription factor , is also vital . In the new PNAS paper , the researchers report that the transcription factor Islet 1 , encoded by the Isl1 gene , plays this important role for POMC . When the researchers blocked cells of the hypothalamus from making Islet 1 halfway through pregnancy , the fetal mice failed to develop any POMC cells . 'Taken together , this work represents the first example of a neuron-specific gene in vertebrates where we have found both the enhancers and a shared transcription factor that control gene expression in the developing brain and then throughout the life span of the adult , ' says Low . Looking to see if the same factors do the same thing in humans will be more complex – and there may be other enhancers and transcription factors involved . But in theory , it could be possible to find drugs to increase the production of Pomc gene products , or to help silence it . 'For humans , Pomc regulation may be part of the equation of weight control , ' says Low . 'We do n't know , but we think it likely , that it may be similar to the mouse model , where its role is like a dial , with a linear relationship between the amount of Pomc expression and the degree of obesity . '
The researchers looked at POMC neurons that can toregulate appetite . When appetite neurons are absent , animals and humans grow obese . This also happens when neurons inside the POMC neurons are n't ##runcated .