July 20, 2012
Waterloo research examines what makes a memory
Listening in on how the brain remembers which way to go.
Left turn or right? Past the white house, or just before it?
We use many clues to get around, and our brains leave a mental crumb trail by activating brain cells — or neurons — known as place cells.
Exactly how the process works remains a puzzle that Matthijs van der Meer is working to solve in laboratories at the University of Waterloo. Using improved technology, Dr. van der Meer and colleagues Anoopum Gupta, David Touretzky and A. David Redish have been able to look even closer at place-cell activity in rats going through a maze.
Their work was published online in June 2012 in Nature Neuroscience.
“We get a better view of what’s going inside the brain by viewing more neurons,’’ Dr. van der Meer says. “We’re pushing it a little more and getting better at it.’’
The more researchers learn about place cells in the hippocampus — a memory-shaping region deep within the brain — the greater the chance of advancing what is known about Alzheimer’s disease and other forms of dementia.
Eavesdropping on the brain
Dr. van der Meer describes the work as “eavesdropping on the activity of the brain.”
As a rat moves through a maze to a food reward, electrodes in a tiny crown on its head pick up the electrical spikes of activating place cells.
But the process isn’t so neatly linear. It appears place-cell activity occurs in chunks that make up sequences. The sequences themselves overlap, forming a spatial experience that may — more or less — be recalled later.
“What we are doing for the first time is looking at the content of these sequences,’’ van der Meer says. “What is the hippocampus storing out of an experience?”
Although Dr. van der Meer is in the department of biology, his background is in computer science. He came to the University of Waterloo in 2010 and is also affiliated with the Centre for Theoretical Neuroscience, located in the south campus.
“The University of Waterloo has a history of doing interdisciplinary things,’‘ he says. “Here we have a great opportunity to get a perspective of the brain that isn’t just grown out of a medical or psychology program. Here, neuroscience research also gets its strength from computer science, engineering and biology.”
