Light improves brain circuits damaged by stroke

Medical Sciences

Neuroscientist Craig Brown: Credit: Courtesy of Craig Brown

A University of Victoria neuroscientist and his team have discovered that stimulating brain circuits with light can improve recovery from a stroke.

A major challenge in stroke research is to understand how stroke disrupts brain circuits that are crucial for sensation and movement. When these circuits are damaged by stroke, people experience profound difficulties in everyday life tasks such as lifting a fork, brushing their teeth, buttoning up a shirt or driving a car.  

Craig Brown’s neurobiology research lab is providing new clues as to what happens to these circuits after stroke and developed a treatment strategy for enhancing recovery.

“What we’ve found is that stroke makes certain circuits in a brain region called the thalamus less active or excitable. These circuits are important for processing sensory information, which allow us, for example, to grasp an object in our hand,” says Brown. “However, when a stroke occurs, these circuits are disrupted and don’t properly process sensory information in a normal way.”

In order to make these circuits work properly after a stroke, Brown’s team forced the circuits to express an algae protein that is sensitive to blue light: “When brain cells express this protein, we can flash light on them and make them excitable again.”

Stimulating these circuits with light for several weeks after a stroke in fact allowed mice in the experiment to regain better use of an affected limb.

“Although this is just a first step in developing a new approach for treating stroke, we are really excited about the possibility that one day, it may be used to treat stroke patients,” says Brown. “We’ll just have to wait and see what the future holds.”

Stroke is the leading cause of disability among adults in Canada and the third leading cause of death, killing 14,000 people annually. Every year in Canada, there are more than 50,000 new strokes, a quarter of them happening to people under age 65. Risk factors include high blood pressure, diabetes and aging.

The study results were published June 23 in Nature Communications.

More information on Brown and his research is available here

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Media contacts

Craig Brown (Division of Medical Sciences) at 250-853-3733 or

Rhys Mahannah (Communications, Division of Medical Sciences) at

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Keywords: neuroscience, Island Medical Program, stroke, research, brain, biomedical, health

People: Craig Brown

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