How do salamanders regrow their tails and spinal cords?

When a salamander loses its tail, it initiates a complex biological process to replace the lost structure. The regeneration of the tail, including the spinal cord, relies on several critical factors.12

The Regeneration Process

The process typically begins with the formation of a blastema, a mass of undifferentiated cells derived from the stump tissues. These cells undergo dedifferentiation, reverting to an embryonic state to provide the raw material for the new growth.13

The Role of the Spinal Cord and Nerves

The spinal cord is essential for tail regeneration; if it is removed or destroyed, the tail will not regenerate. During the process, the spinal cord grows back, and segmental nerve-cell clusters, known as ganglia, differentiate.2

The nervous system acts as a primary regulator, providing the necessary physiological stimuli to trigger and orchestrate the regrowth. While scar tissue formation can act as a barrier to regeneration in many higher vertebrates, salamanders successfully bypass this by maintaining the necessary interaction between the epidermis and underlying stump tissues to form the blastema.13