Table 1.

New laser axotomy and regeneration paradigms in C. elegans, Drosophila and zebrafish

Genetic organism	Neuronal process	Regrowth ability
C. elegans	Commissures of GABAergic motor neurons	54% of severed commissures reaches their dorsal distal end within 12–24 hr [2,4,12]
C. elegans	Commissures of cholinergic motor neurons	Regrow ~50–60 µm at 24hr towards the dorsal cord [3]
C. elegans	Axons of ALM, PLM, and AVM mechanosensory neurons	Regrow ~60–100 µm at 24hr (~1/4 to 1/3 of original axonal length) [2,4,13,28]
C. elegans	Axon of HSN motor neuron	Some extent of regrowth [3]
C. elegans	Sensory dendrite of AWB chemosensory neuron	Only show slow partial regrowth at 24 hr [4]
Drosophila	Class I dendritic arborization (da) neurons*	A dendrite is converted into a regenerating axon [9]
Zebrafish	Axons of trigeminal sensory neurons	Regrow robustly but the ability to innervate original skin territory depends on developmental stages [7]

^*Note: An Axon or dendrite is severed at a distance from its soma by a two-photon laser, except in Class I da neurons the axon is completely removed by a UV laser.