Hair Follicles Play a Surprising Role on Sensory Sensations

Researchers from Imperial College London recently made a groundbreaking discovery about the role of hair follicles in our ability to sense touch. While it was previously believed that only nerve endings in the skin and around the hair follicles were responsible for transmitting the sensation of touch, this new study challenges that notion.

The study, used a cutting-edge RNA sequencing process to examine the cells within hair follicles. They discovered that cells in a part of the hair follicle known as the outer root sheath (ORS) contained a higher percentage of touch-sensitive receptors than equivalent cells in the skin.

But that’s not all. When the researchers conducted experiments by mechanically stimulating these hair follicle cells, they found that the adjacent sensory nerves were also activated. In other words, these hair follicle cells were responsible for registering the sensation of touch!

So, how do these hair follicle cells communicate this touch sensation to the surrounding nerves? The study revealed that these cells release neurotransmitters such as serotonin and histamine through tiny sacs called vesicles. These neurotransmitters then signal to the neighbouring cells, informing them that touch has been detected.

Touch-sensing nerve cells, also known as mechanoreceptors, are responsible for allowing us to feel everything from a gentle breeze to a firm press. In this study, it was discovered that hair follicle cells interact specifically with low-threshold mechanoreceptors (LTMRs), which can sense gentle touches.

While it has long been known that body hair plays a crucial role in our sense of touch, this study delves deeper into the intricate biological interaction between ORS cells and LTMRs. The big question that remains is “why?” Why do hair follicle cells have this unique role in processing light touch?

What’s particularly intriguing about this research is that the experiments were repeated using skin cells instead of hair follicle cells. In this case, histamine was released but very little serotonin. This suggests that there is something special about what the ORS cells do.

The implications of this discovery could extend beyond our understanding of touch sensation. Considering that histamine plays a significant role in several inflammatory skin diseases, including eczema, further research into how hair follicles detect touch could potentially lead to improved treatments and preventative measures.