New Study Discovers Hair Follicles Can Sense Light Touches
Researchers from Imperial College London have conducted a groundbreaking study that reveals an unexpected way in which humans can perceive light touches – through their hair follicles. Previously, it was believed that only nerve endings in the skin and around the hair follicles were responsible for transmitting the sensation of touch.
Using an RNA sequencing process, the research team discovered that cells in a specific part of the hair follicle called the outer root sheath (ORS) possess a higher percentage of touch-sensitive receptors compared to equivalent cells in the skin. To confirm their findings, the scientists cultivated lab cultures of human hair follicle cells alongside sensory nerves. They found that when the hair follicle cells were mechanically stimulated, the sensory nerves nearby were activated, indicating that touch had been recognized.
Moreover, the experiments revealed that the ORS cells released neurotransmitters serotonin and histamine through tiny sacs known as vesicles, which served as signals to surrounding cells. This finding raises questions about the role of these cells and their significance in our skin’s ability to sense touch.
Neural engineer Parastoo Hashemi from Imperial College London expressed excitement about the discovery, stating, “It’s an exciting finding as it opens up so many more questions for these cells: why do they have this role, and what else can we learn from them about how our skin senses touch?”
Mechanoreceptors, also known as touch-sensing nerve cells, enable humans to perceive sensations ranging from a light breeze to a firm press. In this study, the hair follicle cells specifically interacted with low-threshold mechanoreceptors (LTMRs), which are responsible for detecting gentle touches.
While the role of body hair in the sense of touch was already appreciated, this study sheds light on the intricate biological interaction between ORS cells and LTMRs that goes beyond a simple mechanical response. One significant question that remains unanswered is why hair follicle cells play this role in processing light touch.
Bioengineer Claire Higgins from Imperial College London commented on this surprising finding, stating, “Since the follicle contains many sensory nerve endings, we now want to determine if the hair follicle is activating specific types of sensory nerves for an unknown but unique mechanism.”
Additionally, when skin cells were used in the experiments instead of hair follicle cells, it was observed that histamine was released but in minimal quantities of serotonin. This suggests that ORS cells possess a unique capability not found in other skin cells.
The implications of this research extend beyond understanding the mechanisms of touch perception. Histamine, involved in various inflammatory skin conditions such as eczema, plays a significant role in skin health. Therefore, further investigation into how hair follicles detect touch could potentially lead to improved treatments and preventative measures for these dermatological conditions.
“Our work uncovers a new role for skin cells in the release of histamine, with potential applications for eczema research,” said Higgins.
The study has been published in the journal Science Advances, marking a significant step forward in our understanding of the complex sensory processes within the human body.