Pain signalling in humans as rapid as touch signals

Washington: A recent study discovered that pain signals in the body can travel as fast as touch signals.
In monkeys and many other mammals, part of the pain-signalling system can conduct nerve signals just as fast as the system that signals touch. The scientists speculated whether such a system is also present in humans, reported the study published in the journal of Science Advances.
“The ability to feel pain is vital to our survival, so why should our pain-signalling system be so much slower than the system used for touch, and so much slower than it could be?” asked Saad Nagi, principal research engineer.
To answer this, the scientists used a technique that allowed them to detect the signals in the nerve fibres from a single nerve cell. They examined 100 healthy volunteers and looked for nerve cells that conducted signals as rapidly as the nerve cells that detect touch, but that had the properties of pain receptors, otherwise known as nociceptors.
Pain receptors are characterised by the ability to detect noxious stimuli, such as pinching and abrasion of the skin, while not reacting to light touch. The researchers found that 12 per cent of thickly myelinated nerve cells had the same properties as pain receptors, and in these nerve cells, the conduction speed was as high as in touch-sensitive nerve cells.
The next step of the scientists’ research was to determine the function of these ultrafast pain receptors. By applying short electrical pulses through the measurement electrodes, they could stimulate individual nerve cells. The volunteers described that they experienced sharp or pinprick pain.