In a paper published in eLife, “Shortcutting From Self-Motion Signals Reveals a Cognitive Map in Mice” (summarized in “Building a Cognitive Map Through Self-Motion”), Professor Longtin and his collaborators reveal that mice can perform a surprisingly advanced form of spatial thinking. The team used a new method of analyzing movement patterns to demonstrate that mice could connect two locations by imagining a shortcut between them, even if they’d never travelled that route before.
For years, scientists suspected that animals like mice may form “cognitive maps” — internal mental representations of space. But showing this in a measurable, experimental way proved difficult.
To tackle this, Longtin partnered with neuroscientist Leonard Maler from the uOttawa Faculty of Medicine, along with a team of graduate and postdoctoral researchers. Their goal was simple but ambitious: to test whether a mouse could not only remember where food was but also chart a new path between two known places.
In their experiment, a mouse was allowed to roam in a circular arena, discovering two separate food sources. After the mouse learned where food could be found, the researchers removed the food. That’s when things got interesting.
“We saw the mouse start to travel directly from one food location to the other,” explains Longtin, “even though it had never taken that path before.” This meant the mouse wasn’t just reacting to smells or memories of a path. It had formed a mental map and was plotting a shortcut.
Key to the study’s success was a new way of analyzing the mice’s movements. Instead of just tracking how often the mice reached a goal, Longtin and former postdoctoral fellow Mauricio Girardi-Schappo developed a system to analyze the probabilities of different movement trajectories. In other words, they figured out the likelihood a mouse would move in each direction from every possible point in the arena.
They divided the arena into a virtual grid and built heat maps showing where the mice travelled most. Over time, they could see entirely new routes appear — shortcuts that reflected abstract thinking rather than simple trial-and-error wandering.
“It's a bit like how you might figure out a faster way home by imagining the streets from above,” says Longtin. “That kind of thinking is exactly what we were able to detect in the mice.”
“This is why collaboration matters. Physics meets biology, theory meets experiment, and that’s where breakthroughs happen.”
André Longtin
— Professor, Department of Physics
Beyond the novelty of clever mice, Longtin’s findings have serious implications. The ability to mentally map space and imagine routes is a fundamental part of human cognition. It helps us get home, plan errands and remember where we left our keys. But in people with neurological diseases like Alzheimer’s, that ability can begin to break down. Understanding how even a small brain can build a mental map gives scientists a simpler model to study, and a powerful comparison to the human brain.
Longtin and his team now plan to repeat these experiments with mice that have been genetically modified to mimic symptoms of Alzheimer’s. By observing how their ability to navigate changes, the researchers hope to uncover new insights into how memory works, which brain circuits break down and, eventually, how to support or repair them.
For Longtin, who has spent his career at the intersection of physics and neuroscience, the research is also a testament to collaboration. By working alongside Maler and a diverse team of students, he’s showing how important questions about the brain can be tackled from multiple angles.
“This is why collaboration matters,” Longtin says. “Physics meets biology, theory meets experiment, and that’s where breakthroughs happen.”
This discovery is changing how we think about animal intelligence. And it might one day help us understand how diseases like Alzheimer’s affect our ability to navigate the world around us.
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