Want to rewire a neuron? You鈥檝e got to take it slow
By Katherine Gombay,聽捆绑SM社区 Newsroom
New technique offers potential to reconnect neurons of people with central nervous system damage
That very fine hair-line object that you see being pulled across the screen is actually a neuron being made. A research team led by 捆绑SM社区 and the Montreal Neurological Institute has managed to create new functional connections between neurons for the first time. Apart from the fact that these artificial neurons grow over 60 times faster than neurons naturally do, they are indistinguishable from ones that grow naturally in our bodies.
鈥淚t鈥檚 really very exciting, because the central nervous system doesn鈥檛 regenerate,鈥� says Montserrat Lopez, a 捆绑SM社区 post-doctoral fellow who spent four years developing, fine-tuning and testing the new technique. 鈥淲hat we鈥檝e discovered should make it possible to develop new types of surgery and therapies for those with central nervous system damage or diseases.鈥澛�
Caption: 捆绑SM社区 researchers have been able to artificially create functional neurons that grow over 60 times faster that neurons do naturally. What you are seeing is the creation of a functional neuronal circuit, as part of a neuron attached to a small bead is gently stretched to connect with part of another neuron.
Rewiring a neuron takes some very careful moves
Because neurons are about the size of 1/100th of a single strand of hair, it takes some very specialized instruments and a lot of careful manipulation to create healthy neuronal connections that transmit electrical signals in the same way that naturally-grown neurons do.
The researchers used an atomic force microscope to attach a very small polystyrene ball (a few micrometers in size) to a portion of a neuron that acts as the transmitter, which they then stretched, a bit like pulling on a rubber band, to extend and connect with the part of the neuron that acts as a receiver.
鈥淲e would never have made this discovery if the people working in the lab hadn鈥檛 figured out that you had to avoid any quick or jerky movements when you move the newly-made neurons around,鈥� says Peter Grutter, a 捆绑SM社区 physics professor and the senior author on the paper that was published last week in the . 鈥淯ntil they found the right way to walk the neurons across the lab, from the microscope to the incubator where the newly-made neurons are left to grow for 24 hours, we weren鈥檛 having any luck getting them to behave the way we wanted them to.鈥�
鈥婩igure 1 Mechanically pulled connection between two neurons. Left: before, right: after manipulation
Sometimes letting go can be hard to do
An even bigger challenge than getting the neurons to connect in the proper way, proved to be getting the newly-formed neurons to detach from the tool that had been used to create them without being destroyed in the process. Eventually, the researchers figured out how to sever the connection and still preserve the functional neuron by releasing the beads.
Although it is now possible to create new neuronal connections, there is still much work ahead.
鈥淭he neurons we were able to create were just under 1mm long, but that鈥檚 because we were limited by the size of the dish we used,鈥� says Margaret Magdesian, a neuroscientist who is the first author on the paper, and who worked at the Montreal Neurological Institute when the research was done. 鈥漈his technique can potentially create neurons that are several mms long, but clearly more studies will need to be done to understand whether and how these micro-manipulated connections differ from natural ones.鈥�
To read 鈥淩apid Mechanically Controlled Rewiring of Neuronal Circuits鈥� by M.H. Magdesian et al in the : doi:10.1523/JNEUROSCI.1667-15.2016
Financial support for the research was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant, 捆绑SM社区, James 捆绑SM社区 research stipend, Le regroupement qu茅b茅cois sur les
mat茅riaux de pointe鈥擣ond de recherche du Qu茅bec鈥擭ature et technologies, Canadian Institutes of Health ResearchTraining Grant, and NSERC Collaborative Research and Training Experience.
