ABSTRACT
Dendrites do not form macroscopic structures analogous to axons bundled into nerves. There has therefore been little investigation of how neurons respond to dendrite damage. Although in vertebrate animals, dendrites typically reside under bone in the central nervous system, they are damaged by trauma including stroke, traumatic brain injury, and seizure. Whether neurons can recover from irreversible dendrite damage in these scenarios is not yet known. However, acute removal of dendrites using laser microsurgery in model organisms has been used to probe responses of neurons to dendrite damage. After severing, the detached region of the dendrite undergoes stereotyped degeneration similar to Wallerian degeneration of axons. This degeneration is followed by robust regeneration of the dendrite arbor in Caenorhabditis elegans (worms), Drosophila melanogaster (flies), and Danio rerio (zebrafish). While little is known about the proteins that initiate dendrite regeneration, the core axon injury sensing pathway is not used. Some progress has been made on dissecting key cellular processes required for the outgrowth of new dendrites, but, overall, the molecular drivers of dendrite regeneration remain largely open to discovery. Here, we compare dendrite and axon regeneration and summarize what is known in the new field of dendrite regeneration.
