14 DAY TRIAL // People who suffer traumatic injuries to their neck or spinal cord oftentimes remain paralyzed, unable to walk ever again. For these individuals, there may still be hope in alleviating their condition, if we are to trust a new study by researchers at the medical university Karolinska Institutet. In experiments they conducted on mice, the science group there managed to obtain valuable results using light-activated neurons implanted in mice models, AlphaGalileo reports.
The team genetically altered a number of rodents, so that groups of their neurons could be activated by using blue light. When they isolated brainstems or spinal cords from the animals, the researchers noticed that shining blue light on them triggered walk-like activities inside the nerve cells. This finding could be of considerable importance in the field of paralysis studies, which seek to give back at least some mobility to people who have suffered devastating accidents. Details of the amazing results appear in the latest issue of the esteemed scientific journal Nature Neuroscience.
“This new mouse model will impact the way in which future studies examining the organization of neurons involved in walking are performed. We hope that our findings can provide insight that eventually will contribute to treatments for spinal cord injured patients,” KI Professor Ole Kiehn, the leader of the research, explains. The target of the genetic alterations were the initiators and supporters of locomotion, the excitatory neurons.
The team discovered that, for as long as they maintained the light pulse on, the engineered neurons continued to exhibit walking-like behaviors, which stopped when the light was turned off. It was also demonstrated that excitatory neurons inside mouse brainstems delivered a sufficiently strong “go” signal when exposed to this type of light to influence the action of the spinal neurons involved in walking. All the data were collected from in-vitro studies, and not from experiments conducted in living animals.
The study was made possible by the fact that a team at the KI Department of Neuroscience managed to engineer mice that expressed the algal protein Channelrhodopsin2 (ChR2) in precisely the right set of neurons. Previous work was conducted with ChR2 inserted through viruses, but the results were tainted by inaccuracies.