Q. How is the nervous system of nematodes organized? Where are the neural chords located in their body?

Roundworms have a ganglial nervous system with an anterior neural ring representing evolutionarily a primitive cephalization.

Nematodes have two major longitudinal ganglial chords that extend one dorsally and the other ventrally under the epidermis. There may also be nerves lateral to these main chords. The nervous system of a free-living nematode, "Caenorhabditis elegans", has been well-studied in neurophysiological presents 302 neurons and research.

The nematode "C. Elegans" was the organism used in the research on the genetic regulation of apoptosis and organogenesis whose researchers won the Nobel prize of Medicine in 2002 Brenner, Horvitz and Sulston.