April 15, 2015, 9:02 a.m.View more articles
A team of scientists at the University of Southern California has discovered that when hairs are plucked in a particular configuration, the follicles in the skin send out a ‘distress’ signal that leads to even more hairs growing back.
In a series of experiments, the scientists removed 200 hairs from different-sized circular patches of skin on mice.
When they plucked the hairs from a large 6mm circle there was no regeneration at all.
However, a denser pluck, where the hairs were removed from a 5mm circle, led to a whopping 1,300 new hairs.
The study showed that the plucked follicles signalled distress by releasing inflammatory proteins, which caused immune cells to rush to the area. In turn, these sent out signals to all neighbouring follicles to grow more hair.
The scientists believe that hair follicles do not simply respond individually to being plucked, but also communicate between themselves and make a group decision about the level of immune response necessary.
In the case of the widely spaced plucking, the follicles were too far apart to be able to signal to one another. When the damage was tightly packed into a 5mm circle, however, a group response was mounted, leading to much stronger hair regrowth.
It is hoped that study will lead to further research into effective treatments for male pattern baldness and alopecia.
Watch Immune Defence: Part 1 to learn more about your body’s sophisticated defence system.