Plucking mouse hairs in a specific pattern and density not only replaces the missing hairs but triggers a huge surge of regrowth, according to a study by a team of researchers from the University of Southern California.

The process could lead to potential new targets for treating alopecia, a form of hair loss prevalent among men, said study co-author Cheng-Ming Chuong, USC's Assistant Professor of Pathology and a Principal Investigator at the Chuong Laboratory of Tissue Development and Engineering.

Like Us on Facebook

Lead author Chih-Chiang Chen had the idea that hair follicle injury affects its surrounding environment while the Chuong lab had long proven this environment can subsequently stimulate hair regrowth. 

The collaboration led the researchers to test the concept that uses the environment to generate more follicles.

Chen and his team developed a technique to individually pull out 200 hair follicles from a circular patch on the back of a mouse.

When the researchers plucked hairs in a low-density pattern from a patch of 6 millimeters in diameter, no hairs sprouted.

A higher-density plucking from circular areas of 3 and 5 millimeters in diameter led to about 450 and 1,300 new hairs. These included the hairs outside of the plucked area.

Plucking all the hair out in a patch resulted to the growing back of every hair, but with no extra regeneration.

Researchers said this kind of process depends on the concept of "quorum sensing" that shows how a system reacts to a stimulus that can affect some, but not all the members.

Using molecular analyses, the researchers showed the plucked hair follicles triggered a distress signal through proteins, which helped immune cells rush to the injured region.

As a result, these immune cells released molecules that ordered the follicles to grow hair.

Researchers hope they will soon uncover whether a same communication strategy can occur in other parts of the body or in other species, like humans.

The study was published April 9 in the journal, Cell.