Blue Light Can Activate Walking Behavior in Genetically Modified Mice

Blue Light Can Activate Walking Behavior in Genetically Modified Mice

ScienceDaily (Jan. 25, 2010) — Researchers at the medical university Karolinska Institutet have created a genetically modified mouse in which certain neurons can be activated by blue light. Shining blue light on brainstems or spinal cords isolated from these mice produces walking-like motor activity. The findings, which are published in the scientific journal Nature Neuroscience, are of potential significance to the recovery of walking after spinal cord injury.

"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"," says Professor Ole Kiehn, who lead the study.

Excitatory neurons have been suggested to play an important role for the initiation and maintenance of locomotion, or walking. However, this has not been demonstrated directly. In order to test the hypothesis that activation of excitatory neurons is essential to locomotion, a research team at the Department of Neuroscience, Karolinska Institutet, created a genetically modified mouse which expresses a light sensitive protein in excitatory neurons.

The light sensitive protein, Channelrhodopsin2 (ChR2), is normally found in algae and activates the cell it is expressed in when exposed to blue light. ChR2 has previously been introduced into rodent cells by viral infection, but this can be problematic due to exposure and replication demands. The researchers circumvented the problems by creating the first genetically modified mouse to successfully express ChR2 in a specific set of neurons.

http://www.sciencedaily.com/releases/2010/01/100122102429.htm

Why do I have images of KMart flashing through my mind right now? ;)

Well, of course.