People with naturally red hair are in the minority on the planet. Their number does not even reach 2%. But the uniqueness of redheads is not only in this.
Scientists have found that individuals with fiery hair color perceive pain differently than brunettes, brown-haired, fair-haired and blond.
It's all about the genes
Hair color and skin tone are determined by the amount of melanin - a special pigment that melanocytes are responsible for producing in the human body. The color type of a person is laid down at the stage of intrauterine development, based on the set of genes inherited by the child from the parents. However, as it turned out, melanocytes in redheads are somewhat different from the same cells in the bodies of people with a different shade of hair.
Melanocytes have receptors on their surface that respond to MSH - melanocyte-stimulating hormones that activate melanin production and, as a result, darken hair and skin. There are 5 types of such receptors, and each of them is endowed with specific functions. But as it turned out, in people with red hair and white skin, type 1 receptors (MC1R) are inactive. As a result of this mutation, redheads do not produce dark pigment, so their skin is unable to tan. However, these genetic mutations affected not only the color of the hair, but also affected some other features of the organisms of red-haired people.
Pain and nervous system
Red-haired people are less amenable to anesthesia. Professionals know that they usually need a higher dose of anesthetic. But besides this, researchers from the Massachusetts Hospital (USA) noticed that people with red hair endure pain more easily than others. Scientists undertook to find out what caused this. The conclusions reached by the experts were published in the respected scientific publication Science Advance.
The object of analysis for scientists were mice with red hair. In these rodents, as in humans with copper hair, the researchers found inactive type 1 MSH receptors. This suggested that the perception of pain in a mouse and a person with red hair occurs in an identical pattern.
A study found that when MC1R is inactive, less pro-opiomelanocortin (POMC) is produced in animals. The importance of this peptide is indicated by the fact that it is split into several hormones as a result of complex biochemical processes. Some of them are responsible for susceptibility to pain, others for blocking it.
The mechanism of pain perception by the human body is quite complex. Hormones produced by melanocytes stabilize the sensitivity to pain. In addition to them, two more groups of receptors are involved in the process:
- of the fourth type - they increase sensitivity to pain;
- opioids are responsible for pain suppression.
Working together, these receptors allow a person to achieve a balance between excessive sensitivity and complete immunity to pain.
However, in the organisms of people with red hair, this scheme works with some deviations. Due to the lack of a pain-stabilizing hormone, opioid receptors are the first to be activated in the bodies of redheads, which simply “muffle” the pain. Against the background of the absence of type 1 receptors, this leads to a modification of the perception of pain and an increase in the pain threshold.
Some interesting facts about pain perception in redheads
Studies on pain perception in redheads have shown that:
- for effective anesthesia, they need about 20% more anesthetic than other patients;
- redheads require higher doses of drugs such as novocaine and lidocaine for local anesthesia;
- Redheads require lower dosages for opioid pain relief than other people;
- redheads are less susceptible to electric shock, needle sticks;
- redheads easily recognize changes in temperature.
Why the discovery of Massachusetts researchers is useful
Now that specialists have a clear understanding of how red-haired people perceive pain, doctors can more accurately determine the number of painkillers needed, as well as what manipulations the patient can tolerate with minimal discomfort.
In addition, the results obtained can be very useful in the field of pharmacology. For example, based on this knowledge, it is possible to develop a new generation of painkillers, the mechanism of action of which is to block the activity of MSH receptors. By the way, now the most effective painkillers are drugs that stimulate opioid receptors. But such analgesics have a significant disadvantage - they are addictive and withdrawal syndrome.
- UCI Health website. – Do redheads feel more pain?
- Scientific journal "Science Advances".– Reduced MC4R signaling alters nociceptive thresholds associated with red hair.