Researchers at University of California, San Diego School of Medicine report a previously unappreciated phenomenon in which the location of injury to a neuron’s communication wire in the spinal cord—the axon—determines whether the neuron simply stabilizes or attempts to regenerate. The study, published April 30 by Neuron, demonstrates how advances in live-imaging techniques are revealing new insights into the body’s ability to respond to spinal cord injuries.
In this study, senior author Binhai Zheng, PhD, associate professor of neurosciences, first author Ariana O. Lorenzana, PhD, and colleagues used a sophisticated optical imaging technique that allows them to directly visualize the spinal cord in living mouse models. With this approach, the researchers were able to systematically examine the effects of axon injury location on degeneration and regeneration of the injured branch. The injury locations they compared were just before an axon’s major branch point (where a single axon branches into two) and just after it. The injuries just after the branch point cut off one branch, leaving the other intact, or cut both branches.