Figure 1.

Analogous counterparts of the human nervous systems in C. elegans. The human nervous system can be divided, based primarily on the locations, into the central nervous system (CNS) and the peripheral nervous system (PNS). The human CNS consists of the brain and the spinal cord while the rest of the nervous system belongs to the PNS. The nerve ring located at the head region of C. elegans is a CNS equivalent. Neurons within the nerve ring, such as AWC, display limited axon regeneration after injury. In contrast, neurons outside of the nerve ring, including ALM, can effectively regenerate axons after injury.