I had a conversation a few days ago with a friend who was a fitness enthusiast. He was a powerlifter (someone small in built but is able to lift heavy weights) and was interested to know why, despite lifting so much weights, he doesn’t develop any back problems.
As the conversation went on, I remembered reading an article about this group of Pakistani people, who feel no physical pain. It seems that these people can sense hot/cold, sharp and blunt stimuli yet not feel physical pain. They have a mutated gene that causes them to feel no pain since they were born.
“They came across him in the market, sticking daggers through his arms,” said John Wood, a professor at University College London in England and a member of the research team.
How is that possible? Sustained injury yet no physical pain? Isn’t that very dangerous?
Exactly, very dangerous.
They can gnaw endlessly on their tongues and fingers during teething, stick their fingers in their eyes, or suffer major injuries without noticing.
The six people studied for the Nature paper all had permanent injuries to their lips or tongues from biting themselves when they were young.
In a most recent article, it seems like researchers have found a few more genes that can cause insensitivity to pain if mutated. In order to understand this, we need to first understand how pain is experienced.
From my simplistic drawing of the human body above, this is how we experience nociception. Take for example, when a person gets pricked by a sharp needle very lightly on the skin on their lower back, the nerve fiber will sense the sharp stimulus, encodes the stimulus into an electrical signal that gets transmitted to the brain via the spinal cord.
If this prick is very light, no apparent/potential damage is done, the brain will register that it is only a light prick and you will not feel pain. However, if this needle is pricked deep into the skin, the stimulus in this scenario is much greater. the resultant electical signal that gets transmitted to the brain is probably many few times greater. The brain senses that there may be a potential injury going on and you probably will feel some pain. Additional information to know is that, these stimuli hot(scalding/burn), cold(frost), pressure (pinch/punch/prick/slash), chemical (acid, inflammation) can activate this particular nerve pathway and nociception is a protective mechanism of the human body, while pain is the defence mechanism of the brain to warn you of danger.
Coming back to the Pakistani people who have mutated genes giving them insensitivity to pain, these people have a mal-functioning or absent nociceptive pathway, hence little or no signal reaches the brain.
The brain doesn’t know what is going on, so there is no pain (defence mechanism).
How wonderful our body is!