Axon injury and regeneration in the adult Drosophila

Neural regeneration is a fascinating process with profound impact on human health, such that defining biological and genetic pathways is of interest. Here we describe an in vivo preparation for neuronal regeneration in the adult Drosophila. The nerve along the anterior margin of the wing is comprised of ~225 neurons that send projections into the central neuropil (thorax). Precise ablation can be induced with a pulsed laser to sever the entire axonal tract. The animal can be recovered, and response to injury assessed over time. Upon ablation, there is local loss of axons near the injury site, scar formation, a rapid impact on the cytoskeleton, and stimulation of hemocytes. By 7d, ~50% of animals show nerve regrowth, with axons from the nerve cells extending down towards the injury or re-routing. Inhibition of JNK signaling promotes regrowth through the injury site, enabling regeneration of the axonal tract.