At the University of Chicago, scientist explores how knowledge forms

By Yuliya Klochan @YuliyaKlochan

July 2021

Curious about insects and metamorphosis, 8-year-old Jai Yu collected dragonflies from a nearby pond to bring them home for observation. Today, Yu works at the University of Chicago to research fundamental questions about our memories and knowledge formation.

At his Neurophysiology of Memory and Knowledge Lab, Yu’s main question is, “How does the brain convert our experiences into an understanding of the world?”

In other words, how does our brain convert memories into knowledge? Think, for example, about a recent time you went to a party. You probably remember that specific event — a memory — but you also understand the general concept of a party, including what to do and how to talk to other guests — that’s your general knowledge drawn from memories of parties.

Yu and his team — using genetic, neurologic and computational tools — are trying to better understand how knowledge and memory are connected through experiments with rats. In a recent experiment, the team monitored the brain activity in the hippocampus and prefrontal cortex of the rat brain while rats went through a maze.

The hippocampus and the prefrontal cortex are both areas in the brain associated with memory, but they work in different ways. As Yu’s experiment of rats navigating a maze showed, hippocampal neurons known as “place cells” spiked at specific locations in the maze, suggesting that those neurons retained specific aspects of the maze.

On the other hand, neurons of the prefrontal cortex spiked at multiple trajectories, showing generalized knowledge of what it’s like to be in a maze. Generalized and specific aspects of experience registered in connected areas of the brain.

Yu’s work does not solely have theoretical appeal. “Without understanding how the brain does its job normally, then it’s even harder to understand why it’s generating behavior that is out of what’s being expected,” Yu says. “That’s why, fundamentally, you want to study these processes, want to understand better how the brain works to understand what happens if it breaks.”

  In order to perform complex observations with small rodents, Yu’s team requires precisely designed equipment that can’t be bought. Instead, the team makes its own custom equipment in the lab, using 3D printers to create intricate parts and putting them together by hand. The lab members often use drills they bought at a hardware store to create customized high-tech precision.

Yu opened his lab in July 2020, in the middle of the pandemic. He and his research assistant, Zac Leveroni, worked out of a seminar room for eight months. They experienced delays and shortages and, once, had a huge microscope delivered to a high school down the road.

None of this seemed to faze Yu. “It was like watching a remarkable improviser,” says Leveroni. In the end, all that went wrong during COVID didn’t hurt the creation of the lab too much “just because [Dr. Yu] was able to make it work,” according to Leveroni.

The secret to navigating unpredictable circumstances wasn’t the only lesson Yu taught Leveroni. “I don’t think I could have ever been justified asking for a mentor like Dr. Yu,” Leveroni says. “He’s a very gifted teacher.”

“Jai really knows his stuff,” says Jacob Proctor-Bonbright, an undergraduate research intern at the lab. “He’s kind of like a teacher, in the fact that, if I have made a mistake, he’s not going to necessarily correct me on that. He’s gonna be like, ‘Okay, what do you think is going on here?’”

To Yu, answering questions about the brain with people like Leveroni and Proctor-Bonbright is what matters the most. He hasn’t thought about his legacy, but hopes to leave behind “the people that I’ve trained and the finding that this lab makes, answering important questions that have not been answered before,” he says.

For future scientists, Yu has one piece of advice: ask the right questions if you don’t know something. “And if I don’t know it, can I ask someone? And if no one can answer it, can I find it out? Can I find out the answer by myself?” Yu says. “I think the ‘why’ is the most important thing.”