Dr. Steffany Bennett

Director, Neural Regeneration Laboratory Ottawa Institute of Systems Biology
Researcher of the month: 
Mar 2011

Who says that diet doesn’t matter? Not Dr. Steffany Bennett, who researches neurodegenerative changes in Alzheimer’s disease (AD) and directs 18 multidisciplinary collaborators who participate in the STIHR/CIHR Training Program in Neurodegenerative Lipidomics.

Their cutting-edge research is showing that, by changing what we eat, we may be able to alter the composition of membranes that encase our neurons and other brain cells.

“These shells are actually made of oil – tens of thousands of individual lipid molecules,” explains Dr. Bennett. “They make up the impermeable water barrier that forms the outer garment of any cell.”

Because lipids – like proteins – are so small, they are usually considered as a homogenous sea of identical molecules, but nothing could be further from the truth, she says. Each lipid is distinct.

“What’s truly awesome is that each one of us has a slightly different make-up of different types of lipids in our brain cell membranes,” she says, “based on what we eat.”  

Her team works to develop lipid profiles of brain cell membranes in healthy and diseased states in the hopes of identifying ways to restore balance to abnormal brain cells in AD, Parkinson’s disease and other neurodegenerative disorders.  

“What makes up your cell membrane dictates how it responds to its environment,” she explains. “It’s your raincoat – what your cell uses to protect itself. Altering the fabric of this raincoat might render neurons resistant to some of the genetic and environmental effects of AD. That’s why I think lipidomics has the potential to make a real difference.”

Dr. Bennett and her collaborators adopt a zoom-in, zoom-out approach to their studies. They identify AD-related changes in post-mortem tissue samples and then profile lipid changes in neurons, astrocytes and dendrocytes in certain regions of the brain before examining individual cells and even organelles inside those cells.

“We start out big, become increasingly focused, then come back up to find out whether a global intervention, for example, changing an animal’s diet, can provide some of the (fatty acid) side chains that appear to be missing in the disease state.”

In other words, the brain cell’s “raincoat” is made of many different threads. Dr. Bennett and her collaborators are trying to identify the threads and find out if changing those threads will make the raincoat more or less effective in protecting brain cells from neurodegenerative diseases.

One of her greatest triumphs came recently, when she witnessed cognitive improvements in one small mouse, which had showed a large number of AD-related behavioral impairments, over the course of a week after changing its diet. “It was fantastic to see that lipid changes can really make a difference. 

“My greatest challenge is the disease that I study,” she adds. Her greatest fear is one that every scientist faces every day – the worry that her work will fail to make a difference to people robbed of whom they are by AD.

New technology spurs investigation

Dr. Bennett’s laboratory is one of the few places in North America where scientists can use mass spectrometry to do lipid profiling.

Lipids are difficult to manipulate genetically, but they are amenable to intervention. “There’s an untapped potential for therapeutic applications, but because it’s been so difficult in the past, we’ve never tried it,” says Dr. Bennett. “With mass spectrometry and new technologies, we now have the capacity to look at lipids with the same kind of rigor as genes and proteins.”

The Neural Regeneration Laboratory will soon have a brand new supertoy – the first Simulated Emission Depletion (STED)-CW system in Canada. It can study lipid molecules on a nanoscopic level. Current technology shows thousands of lipids as “one big amorphous blob”. The STED-CW will enable scientists to see individual lipids at extremely high resolutions.

“We will actually be able to monitor the differences that we’re making at the molecular level,” she says. “That will definitely show allow us to see whether we are rendering cells more resistant or not.”

Once the technology is up and running, Dr. Bennett plans to welcome as many collaborators as possible to use the STED-CW, because “the more brains, the better.”

Electric enthusiasm

With long, flowing blond hair and a penchant for using words like “awesome” and “cool”, Dr. Bennett doesn’t exactly fit the stereotype of a research scientist. Capable and outgoing – you can see her on YouTube – she makes science exciting and accessible for the public and biomedical researchers alike. Her bubbly enthusiasm is catchy and its intensity, charismatic.

She is an accomplished teacher and administrator. When she talks about the potential of lipidomics, “people kind of get excited and want to work together on a project.”

Oddly enough, in university, Dr. Bennett wanted to be an historian, not a scientist. Her undergraduate thesis focused on plant compounds that doctors used to treat mental disorders in medieval Europe. Bartholomeus Anglicus, an encyclopedist who wrote one of the first drug textbooks of the middle ages, inspired her to look beyond the written page. She realized that she didn’t want to study biomedical researchers of the 13th century. She wanted to be a biomedical researcher.

During her career, the 44-year old biochemist has earned investigator awards and recognition from the Canadian Foundation of Innovation, CIHR, Ontario Mental Health Foundation, Alzheimer’s Society of Canada and Premier’s Research Award of Excellence. Dr. Bennett is a Harvard Lefler scholar. Report on Business named her one of “Canada’s Top 40 under 40” in 2000.

Her research is currently funded by CIHR and the Canadian Foundation Innovation/Ontario Research Fund Leader’s Opportunity Fund (with Drs. Daniel Figeys and Mary Ellen Harper).  

For further information, please contact Dr. Steffany Bennett using the Email contact form