Hediye Nese Cinar

Neurosurgery: Functional regeneration after laser axotomy

Understanding how nerves regenerate is an important step towards developing treatments for human neurological disease, but investigation has so far been limited to complex organisms (mouse and zebrafish) in the absence of precision techniques for severing axons (axotomy). Here we use femtosecond laser surgery for axotomy in the roundworm Caenorhabditis elegans and show that these axons functionally regenerate after the operation. Application of this precise surgical technique should enable nerve regeneration to be studied in vivo in its most evolutionarily simple form.

Nerve Regeneration in Caenorhabditis elegans After Femtosecond Laser Axotomy

We perform submicrometer-scale surgery with femtosecond lasers to study nerve regeneration in the tiny nematode Caenorhabditis elegans, an invertebrate model organism with only 302 neurons. By cutting nanoscale nerve connections inside the nematode C. elegans , the feedback loops that control backward motion of the worm can be disconnected. This operation stops the whole worm from moving backward while leaving its forward motion intact. The femtosecond laser-based axotomy creates little peripheral damage so that the cut axons can regrow, and the worms recover and move backward again within one day. We conduct several assays to assess target specificity, damage threshold, and the extent of femtosecond laser axotomy. We also study nerve regeneration in touch neurons, and report an interesting type of nerve regeneration that salvages the severed parts of neurons from degeneration. The use of femtosecond laser pulses as a precise surgical tool allowed, for the first time, observation and study of nerve regeneration in C. elegans with a simple nervous system. The ability to perform precise axotomy on such organisms provides tremendous research potential for the rapid screening of drugs and for the discovery of new biomolecules affecting regeneration and development

Nerve Regeneration Following Femtosecond Laser Nano-Axotomy

We demonstrate nanoscale surgery with femtosecond lasers in C. elegans, and for the first time, show nerve regeneration in such a tiny organism with morphological and behavioral studies. This technique opens up tremendous research potential.

Nerve regeneration after femtosecond laser nanosurgery

We demonstrate sub-micron scale surgery with femtosecond lasers in a tiny living organism. By just cutting few nano-scale nerve connections inside the nematode C. elegans, we succeeded to stop the whole animal from moving backwards. This delicate axotomy keeps the surrounding of the severed axons un-damaged so that the axons can regrow back, and the worms recover and can move backwards again. These results demonstrate, for the first time, nerve regeneration in such a tiny organism, in its evolutionarily simplest form. The ability to perform precise sub-micron scale axotomy on such organisms provides tremendous research potential for rapid screening of drugs and discovery of new biomolecules affecting regeneration and development.