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Finding the right path: PlexinC1-negative dopaminergic neurons for personalized cell replacement therapy of Parkinson’s disease

At Laval University, Master’s student Caroline Lafrechoux is investigating how to guide the axons, or the connectors, between transplanted cells in the area of the brain where dopamine-producing cells are dying. If she can find a way to guide the axons to the right locations within the brain, she’ll improve the prospects for brain cell transplantation as a way to replace the damaged and dying cells that are causing Parkinson’s disease.

Neuroscientist Caroline Lafrechoux has been fascinated with the networks of neurons and electrical signals in the brain since she was seven years old, and saw a young cousin suffer an epileptic seizure.

When she learned that epilepsy is the result of electrical or signalling disturbances in the brain, the explanation sparked Lafrechoux’s determination to find out more about this mysterious organ.

Today, thanks to the two-year $30,000 Parkinson Canada Graduate Student Award funded by the Lanka Charitable Foundation, the Master’s student at Laval University is channelling her early fascination with those neural networks into research on the connections between cells in the brains of people with Parkinson’s disease.

Using a mouse model, Lafrechoux is investigating how to guide axons, the long, thread-like portion of cells, into position so they can conduct signals from newly transplanted brain cells to other cells, directing movement.

If Lafrechoux can figure out how to introduce a chemical cue that guides the axons where they need to go, she will have solved a crucial piece of the puzzle that has so far stymied researchers trying to use cell transplantation to treat Parkinson’s.

“What I’m hoping will happen is that once I inject these new neurons, I will restore normal motor locomotion,” she says. “I’m hoping that the cells I inject will replace the ones that have been lost—exactly.”

Eventually, if Lafrechoux can restore connections and neural pathways among mouse brain cells, she wants to engineer human brain cells that she can transplant into the mouse models.

“If it works … it would give hope for cell replacement therapy,” she says. “It’s personalized medicine, because you can take a patient’s own cells, transform them, and put them back into their brain, replacing the ones that have died.”

Although Lafrechoux enjoys the challenge that Parkinson’s disease presents for researchers, she is motivated by the suffering the disease causes people who have it.

“We absolutely need to find an answer,” she says.

Read about other researchers recently funded by the Parkinson Canada Research Program by visiting the research section of www.parkinson.ca.