Section through a neonatal dorsal root ganglion (DRG) showing the cell bodies of different populations of sensory nerves. The myelinated A fibers that detect tactile sensations are shown in red. The peptidergic neurons that detect pain and mediate neurogenic inflammation via the release of certain peptides both at the painful site and in the spinal cord are shown in green. The non-peptidergic pain neurons are shown in blue. Bundles of nerve fibers can also be seen within the ganglion.