Femtosecond laser ablation. A. Diagram of laser surgery setup. Amplified femtosecond laser pulses are tightly focused by an objective lens (1.4 NA) to dissect targets positioned with a three-dimensional piezoelectric stage and visualized by fluorescence microscopy. B. DiO-stained amphid dendrites before and after severing the middle dendrite using 3-nJ pulses without visibly affecting neighboring dendrites as close as 500 nm away. C. An example of a GFP-labeled AFD dendrite retracting after surgery using 6-nJ pulses. D. Confocal microscope image showing GFP-labeled AFD neurons the day after surgically severing one dendrite. The position of the cut along the dendrite is representative of all experiments. E. Phasmid DiO (pre-surgery) and DiI (post-surgery) staining 24 hours after surgery of the PHA dendrite. The PHA cell body does not absorb DiI because it is physically disconnected from its sensory endings. The cut in the dendrite is indicated with the arrow.