London: Struggling to shed the flab? Blame your genes, say scientists after they claim to have discovered a "greedy gene" that makes one eat even when one is full as it breaks down communication between the body and the brain.
A team at Georgetown University Medical Centre has shown in tests on mice that a mutation on Bdnf gene broke down communication in the body and led to non-stop eating and rapid weight gain, a finding which could pave the way for treatments for obesity, the 'Daily Mail' reported.
For their study, the scientists studied variations in the Bdnf gene in mice. Humans also have this gene and it has been linked to obesity, but the team members say it was not clear until now exactly how it worked.
After a meal, the activity of this gene transmits chemical signals down a chain of brain cells until they reach the hypothalamus, which receives the message that you are full and suppresses the appetite.
However, in mice which had a mutation of this gene, these chemicals -- leptin and insulin -- were not being transmitted to their target, and they ate twice as much as those without the mutation. Lead researcher Dr Baoki Xu said: "This discovery may open up novel strategies to help the brain control body weight." His team found the Bdnf gene has "short" and "long" versions which form at an early stage in the womb.
Those with the "long" form successfully sent the chemical signals to say "I'm full" through a "superhighway" of neurons in the brain to the hypothalamus.
However, in those with the short form, the signals reached some brain cells but could not be picked up by the dendrites -- the branch-like "fingers" coming out of the cells which pass messages on to the right place.
Dr Xu said: "If there is a problem with the Bdnf gene, neurons can't talk to each other, and the leptin and insulin signals are ineffective and the appetite is not modified. We have opened the door to both new avenues in basic research and clinical therapies, which is very exciting."