2. Target of pain: central and peripheral

## 2.1. Peripheral targets

At the peripheral terminal, pro-inflammatory mediators are released from the mast and schwann cells, macrophages and neutrophils which are resident and migrating cells, respectively, due to the injury to cells and blood vessels in return of stimuli, for example, a tissue damage or infection. Dorsal root ganglion (DRG) cells hold receptors for these mediators, which upon activation initiates a cascade of event from the intracellular kinases. In turn, receptor phosphorylation causes the terminal sensitization, amplified afferent movement and stimulation at lower threshold.
