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