FOCAL POINT  (Left to right) Axel Behrens, Xavier Fontana, Mariya Hristova, Gennadij Raivich, and colleagues (not pictured) investigate how Schwann cells promote nerve regeneration by up-regulating the transcription factor c-Jun. In mice with c-Jun–deficient Schwann cells (far right), fewer facial neurons reconnect to the whisker pads after injury, as indicated by the decreased labeling of neuronal cell bodies compared with wild-type animals (second from right). c-Jun induces the expression of several signaling factors, including GDNF and Artemin, that signal to injured nerve cells to promote neuron survival and axonal outgrowth.

PHOTOS COURTESY OF THE AUTHORS