Abstract

Pain is the unpleasant physical feeling which occurs during tissue damage. Pain is an important physiological protective mechanism that is essential for the detection and prevention of contact with noxious stimuli as shown by its presence in animals diverse as snails, reptiles and mammals. Such noxious stimuli are detected by specialized sensory neurons called nociceptors. SCN9A encodes the sodium channel Na v 1.7 that is expressed at high densities on nociceptors. Recent genetic studies have identified this channel to underlie a the disorders primary erythermalgia and congenital insensitivity to pain. These conditions are characterized by very different pain phenotypes. Remarkably recent work has shown that these disorders are caused by mutation in the same Na v 1.7 channel. These discoveries allow better understanding of the molecular mechanism of pain.