Dr. R. Andrew Tasker

Following leads in Neuroscience Research

A mollusc, fished locally in PEI and sold worldwide, turned Dr. Andrew Tasker’s world upside down.

When the leading neuroscientist accepted his first posting at the University of Prince Edward Island (UPEI), he had planned to continue his post-doctoral work on the neurological effects of analgesic drugs on chronic pain.

His intentions were sidetracked after a small group of people in Montreal developed neurological symptoms, including seizures and amnesia, after eating contaminated PEI mussels. They had contracted amnesic shellfish poisoning (ASP), caused by a deadly toxin known as domoic acid.

At UPEI’s Atlantic Veterinary College, Tasker shifted his research focus to study how domoic acid adversely affects the brain. He became an internationally recognized expert in this area, but serendipity continued to play a role in shaping his path ahead.

Several years later, a clinical paper reported that one of the Montreal patients had developed temporal lobe epilepsy after ASP. Armed with his knowledge of domoic acid, Tasker decided to study “translation in reverse” to figure out how ASP led to epilepsy. He reasoned that this work might help to determine how epilepsy developed in the brain.

“We were able to study the process of becoming epileptic,” he explains. “We were among the first to study pre-symptomatic development of disease in the brain. I saw it as an opportunity to carve out a niche in brain research. We started with the case studies of patients, then went backwards from people to animal models to cells.”

The snowball effect

Tasker’s groundbreaking research soon broadened to include other brain disorders.

“Many brain diseases aren’t identified until their symptoms are so severe and brain damage so widespread that they are difficult, if not impossible, to reverse. At that point, therapy is largely palliative,” says Tasker, Professor of Neuropharmacology and Jeanne and J. Louis Lévesque Research Professor at UPEI.

Today, he and his team are trying to identify biomarkers that signal the early development of many brain diseases, including epilepsy, Alzheimer’s disease, schizophrenia, depression and autism. They hope to unlock the mysteries of brain function and, ultimately, find ways to cure or prevent neurological diseases. 

“For me, it’s always very important to understand how our actions in the laboratory have relevant applications in the real world.” He attributes this guiding principle to his post-doctoral studies under neuropsychologist Ronald Melzack at McGill University. “It made me realise that the stuff I do in the lab can have real-world applications.”

In recognition of his work, Tasker has been named a Fellow of Canadian Academy of Health Sciences. In 2016, he was awarded an honorary professorship at Aarhus University, Denmark.

Tasker received his BSc, MSc and PhD at Queen’s University. His father was a pathologist; his uncle, a surgeon; his grandfather, a family doctor; but he couldn’t see himself in family practice.

“I’ve always been more interested in asking and answering questions. At UPEI, I have the flexibility to try new ideas and maintain a good work-life balance.”

Overcoming stumbling blocks with innovation

Before you can figure out how brain diseases develop, you need to study early neurological changes in laboratory models – stand-ins for the human brain. The results of laboratory studies can point to ways ahead.

When Tasker began to study pre-symptomatic brain disease, he and other neuroscientists lacked suitable laboratory models for their research. So, over a ten-year period, he and coworkers at three departments in three separate faculties within UPEI devised and patented a number of world-class animal models of CNS diseases.

The animal models, which slowly develop brain disease, can be used to study primary brain dysfunction before symptoms develop and in preclinical trials of promising new compounds to treat epilepsy, stroke, schizophrenia, Parkinson’s and other brain disorders.

“We know we’re on the right track,” states Tasker. “We’ve been able to identify early changes in brain function that others have used to develop better diagnostic tests.”

UPEI has licensed the models nonexclusively to a local bioscience company, so both the pharmaceutical industry and neuroscientists worldwide can use the laboratory models to advance their research. 

Pivotal role in NA-1 stroke research

In 2012, the Canadian Stroke Network invited Tasker to join a pan-Canadian team of researchers “to look at big picture possibilities” in stroke research

A stroke expert within the group, Dr. Michael Tymianski of Toronto Western Hospital, had invented a promising new molecule, NA-1, that could potentially limit brain cell death in stroke victims. The next step was to test whether it worked.

Tasker’s laboratory stepped up and conducted some of the first preclinical trials. “Basically, we evaluated the molecule in rat stroke. We found that it was highly effective in preventing brain damage and preserving brain function, even when given hours later. The long-term effects on brain function were remarkable. We were excited to see the results and be involved in the study.”

NA-1, which The Globe & Mail has described as Canada’s first “blockbuster” drug since insulin, is now being studied in a phase III clinical trial called FRONTIER.

Maverick at work

Tasker likes thinking outside the box almost as much as he enjoys teaching his graduate students how to approach research challenges from new and innovative directions.

Take depression, for example. Thanks to a three-year, $30,000 Jeanne and J-Louis Lévesque research professorship, Tasker will continue to study the neurological basis of depression and evaluate new approaches to improving the effectiveness of antidepressant medication.

For centuries, traditional Chinese medicine has used ginseng to restore balance in people who suffer from depressive disorders. Working on a hunch, Tasker plans to study whether this ancient herbal remedy can enhance the efficacy of antidepressant medication.

“Antidepressants often take weeks, even months, to work, and in up to half of cases, they don’t work at all,” he explains. “What if we used the active ingredients in ginseng to help these drugs become more effective? It’s a new idea, and I don’t know if it will work, but it’s worth trying to find out.”