Somata - Nissl Stain -

Nissl staining shows DNA and RNA in neuronal somata. Here dorsal root ganglion (DRG) cell somata are seen with supporting and glial cell nuclear staining. Each DRG is evident by light staining of the nucleus and the dark nucleolus (dot). The perineuronal cells (satellite cells) ring each DRG soma. Elongated nuclei are of the myelin forming Schwann cells and mark the region where axons are passing into nerves.
Note the variability in size of the DRG somata. These size differences are related to the receptor type of the axonal projection and distance that it projects. This serves to adjust the speed of conduction that is required for timing coincidence of signals into sensory centers.

Note the variability in size of the DRG somata. These size differences are related to the receptor type of the axonal projection and distance that it projects. This serves to adjust the speed of conduction that is required for timing coincidence of signals into sensory centers.