PARIS: Few things strike fear into the human heart like a receding hairline, but a path-breaking study points for the first time to a genetically-based remedy for hair loss.

In experiments on mice, scientists at the University of Pennsylvania showed that the skin of wounded animals can naturally regenerate the follicles from which individual hairs grow.

They also identified a gene that is essential for normal hair development, and were able to stimulate or stop hair growth by boosting or inhibiting the protein's activity at a molecular level, opening the way to non-invasive therapies.

The results have stunned many scientists, who have long assumed that mammalian hair follicles were a non-renewable resource. The human head comes equipped with approximately 100,000 of these tiny, hair-generating organs, and once they stop working, it was thought, the scalp was doomed to gradual exposure.

The study, published in the British journal Nature, is all the more surprising because it reproduces results observed 50 years ago in rabbits, mice and humans that were widely dismissed at the time and have been ignored ever since.

Lead author of the study, released yesterday, dermatologist George Cotsarelis, is also co-founder of a company, Follica that has licensed technology to develop hair-restoration treatments.

Creeping baldness is a source of distress to millions of people all over the world. Hair-challenged adults spend more than USD one billion every year on mostly bogus remedies in the United States alone, according to the Federal Drug Administration.