Painful Channels in Sensory Neurons

Pain is an unpleasant sensation experienced when tissues are damaged. Thus, pain sensation in some way protects body from imminent threat or injury. Peripheral sensory nerves innervated to peripheral tissues initially respond to multiple forms of noxious or strong stimuli, such as heat, mechanical and chemical stimuli. In response to these stimuli, electrical signals for conducting the nociceptive neural signals through axons are generated. These action potentials are then conveyed to specific areas in the spinal cord and in the brain. Sensory afferent fibers are heterogeneous in many aspects. For example, sensory nerves are classified as Aα, -β, -δ and C-fibers according to their diameter and degree of myelination. It is widely accepted that small sensory fibers tend to respond to vigorous or noxious stimuli and related to nociception.