Penn State University molecular biologists have discovered a brand-new pathway for repairing nerve cells that could have implications for faster and improved healing. The researchers describe their findings in a paper titled "Dendrite injury triggers DLK-independent regeneration," which will be published in the 30 January 2014 issue of the journal Cell Reports. These findings demonstrate that dendrites, the component of nerve cells that receive information from the brain, have the capacity to regrow after an injury.
Previous studies using many models have shown that when nerve cells, or neurons, are injured they repair the damage through regrowth of axons, the component of a neuron that sends information to other cells, explained co-author Melissa Rolls, associate professor of biochemistry and molecular biology at Penn State. "For example, if you break your arm and the bone slices some axons, you may lose feeling or movement in part of your hand. Over time you get this feeling back as the axon regenerates."
Using the fruit fly (Drosophila) as a model system, the researchers took what Rolls calls a "radical approach," cutting off all of the dendrites in neuron cells. "We wanted to really push the cells to the furthest limit," she said. "By cutting off all the dendrites, the cells would no longer be able to receive information, and we expected they might die. We were amazed to find that the cells don't die. Instead, they regrow the dendrites completely and much more quickly than they regrow axons. Within a few hours they'll start regrowing dendrites, and after a couple of days they have almost their entire arbor. It's very exciting-these cells are extremely robust."