Optogenetic mouse model aids study of limb spasticity after spinal cord injury

Researchers at the University of Ottawa have made a significant advancement in the field of spinal cord injury research, developing a novel optogenetic mouse model that could lead to improved treatments for limb spasticity. The study titled “An optogenetic mouse model of hindlimb spasticity after spinal cord injury” is published in the journal Experimental Neurology.

Spasticity, characterized by involuntary and sustained muscle contractions, affects approximately two-thirds of Canadians with spinal cord injuries. This new model addresses the limitations of previous research methods, offering a more reliable and consistent approach to studying this debilitating condition.

“Our team has created a transgenic mouse model where we can activate specific nerves in the hind paws using blue light. This allows us to reliably trigger the neural circuits potentially responsible for spasticity after spinal cord injury,” explains Tuan Bui, Chair and Professor in the Department of Biology at uOttawa. “By utilizing optogenetics, we were able to activate specific sensory pathways with light, allowing us to induce spasticity in a controlled manner.”

The research, conducted over the past three years at the Motor Circuits Laboratory at the University of Ottawa, involved generating a unique transgenic mouse model and developing a method to induce limb spasticity consistently. This innovative approach enables researchers to study the underlying causes of spasticity more effectively and could accelerate the development of new treatments.

The study was a collaborative effort involving Ph.D. graduate Sara Goltash, honors undergraduate student Riham Khodr, and postdoctoral fellow Alex Laliberte. Their work not only advances our understanding of spasticity but also showcases the University of Ottawa’s commitment to cutting-edge research in neuroscience and rehabilitation.

Alex Laliberte, last author of the study, emphasizes the potential impact of this research, “Our new animal model could significantly facilitate the study and discovery of new therapeutics for the treatment of spasticity. By providing a more reliable experimental platform, we’re opening doors to better understand and potentially alleviate this challenging condition.”

“Our study shows that spasticity starts as early as two weeks after spinal cord injury, a critical timeframe for intervention. Understanding the differences between sexes in spasticity responses could also lead to more targeted treatments in the future,” Laliberte notes.

This breakthrough comes at a crucial time, as the need for effective treatments for spinal cord injury complications continues to grow. The team’s innovative approach could pave the way for more targeted and efficient therapies, potentially improving the quality of life for millions of people worldwide affected by spasticity.