The axolotl has extraordinary regenerative capabilities, and the axolotl tail is particularly suitable to study regeneration of the spinal cord and locomotor-related spinal circuits because it possesses all relevant structures that are found further up the body axis. Using molecular genetic analysis, GCaMP imaging and optogenetics, I aim to investigate the patterning and functionality of the regenerated nervous system on multiple levels from sensory input to activity to motion: (1) projection patterns, connectivity, and muscle innervation within and across muscle segments; (2) swimming behaviors and activity of neurons; and (3) sensory input into central pattern generators (CPGs). Volumetric imaging showed that the muscle tissue is not well segmented after regeneration. However, even though segmentation is not perfect, a transgenic CAGGS-GCaMP reporter revealed that regenerated muscle fibers are highly active when induced with neurotransmitters like Acetylcholine or N-methyl-D-aspartate. The ultimate read-out for muscle activity is swimming. Already 3 weeks after amputation the animals showed swimming ability, after 6 weeks, when the tails reached the length of the age-matched controls, no obvious difference in S-wave motions were detected. Besides spontaneous swimming, I observed that regenerated tails are less reactive to touch-induced escape responses. All in all, the preliminary results showed that even if patterning is not fully reestablished, the regenerated neuronal network is functional. In the future, this study will tell us how accurate organ regeneration needs to be, to be still functional, and provide a basis for closer investigation of patterning and connectivity in less regenerative mammalian species.