UBC associate professor of cellular and physiological sciences Dr. Mark Cembrowski (left) and PhD student Adrienne Kinman observe ovoid cells active in the hippocampus of a mouse. (Credit: Cembrowski Lab/UBC Faculty of Medicine)

VANCOUVER — From recognizing a friend’s face to finding our keys, our ability to remember objects shapes how we navigate daily life. But what’s behind this all-important mechanism that controls what we can remember and what we can’t? Scientists at the University of British Columbia have discovered unique brain cells responsible for these crucial memories, opening new possibilities for treating memory-related disorders.

“Object recognition memory is central to our identity and how we interact with the world,” explains Dr. Mark Cembrowski, the study’s senior author and associate professor at UBC, in a statement. “Knowing if an object is familiar or new can determine everything from survival to day-to-day functioning, and has huge implications for memory-related diseases and disorders.”

In their study published in Nature Communications, researchers identified an unusual type of brain cell they named “ovoid neurons” because of their oval, egg-like shape. These cells behave differently from other brain cells. They become very active when we see new objects but stay quiet when we encounter familiar ones.

The discovery came when Adrienne Kinman, a PhD student in Dr. Cembrowski’s lab and the study’s lead author, noticed something unusual while analyzing mouse brain samples. She spotted a small cluster of neurons with highly distinctive gene expression. “They were hiding right there in plain sight,” said Kinman. “And with further analysis, we saw that they are quite distinct from other neurons at a cellular and functional level, and in terms of their neural circuitry.”

Located in the hippocampus, a brain region vital for forming memories, these oval-shaped cells stand out from their pyramid-shaped neighbors. They form their own network, connecting to a specific brain region called the anterior thalamic nuclei.

To study these cells in action, the research team used a sophisticated technique that made the cells glow when active. Using a miniature microscope, they watched what happened in the mice’s brains as the animals explored new and familiar objects. When a mouse encountered a new object, these oval cells lit up brightly. But when the same mouse saw an object it had seen before, even months ago, these cells stayed quiet.

“What’s remarkable is how vividly these cells react when exposed to something new. It’s rare to witness such a clear link between cell activity and behavior,” Kinman noted. “And in mice, the cells can remember a single encounter with an object for months, which is an extraordinary level of sustained memory for these animals.”

To prove these cells were actually controlling object memory, the researchers used optogenetics, a technique that allows them to turn specific brain cells on or off using light. When they turned off the oval cells while mice were exploring new objects, the mice couldn’t form memories of these objects. However, this didn’t affect their ability to remember locations, showing these cells specifically handle object memory, not spatial memory.

In another fascinating experiment, turning these cells on made mice treat new objects as if they were familiar, essentially creating artificial memories. This worked even months after the mice had first seen an object, suggesting these cells help both form and maintain long-term memories of objects.

The research team is now investigating how these cells might be involved in conditions like Alzheimer’s disease and epilepsy. In Alzheimer’s, patients often struggle with recognition memory, forgetting what everyday objects are or failing to recognize photos of loved ones. The team hypothesizes that when ovoid cells become dysregulated, either too active or not active enough, they could drive symptoms of these conditions.

The study could eventually lead to better treatments for such memory disorders. By understanding exactly which brain cells handle different aspects of memory, scientists might be able to develop more targeted treatments for conditions that affect memory.