<i>In vivo</i> laser axotomy and time-lapse imaging.

<p>a) Images from a continuously immobilized <i>C. elegans</i>, showing an ALM neuron severed 20 µm from the cell soma (top panel) immediately following laser axotomy and (bottom panel) after 10 hr. Arrow indicates lesion point. b) Average regenerative outgrowth of ALM neurons severed at the indicated distances. Outgrowth was measured from images taken at 10 hr post surgery and categorized as initiating from the lesion point or from the cell soma (* indicates p<0.05 by Student’s t-test). c) Average FRET signals measuring cellular calcium response to laser axotomy. At each time point, two channel fluorescent FRET images of the target neuron where averaged across the cell soma and along the axon within 5 µm of the lesion point to measure intracellular calcium levels in those regions. Arrows indicate time of laser damage (t = 0 s). Shaded regions indicate standard error on the mean at each time point. n indicates number of worms assayed.