While it might sound like a cute gift to buy for your pet mouse, a new set of virtual reality goggles have a much more serious purpose. The inventors say they should help advance research into Alzheimer's disease and other brain conditions.
As anyone who's ever seen a mouse navigate a maze knows, the animals are often used in studies to understand the way in which brains function. For example, just this year, studies with the rodents showed how activating certain brain cells not only slowed aging but also extended their lives. Another study in 2024 showed how brains store three copies of every memory. And a study last year demonstrated how a brain tweak led mice to sleep less but feel as awake as if they had rested longer.
Mouse studies have also been critical in the quest to unravel the causes of Alzheimer's disease. For example, the same researchers at Cornell University who invented the new goggles have previously shown a reduction in blood flow in the brains of mice afflicted with the condition.
“That was very exciting from the perspective of, hey, maybe there is something you could do in Alzheimer’s disease that could recover some cognitive function,” said lead researcher Chris Schaffer. “The next steps are to uncover how blood flow improvements are improving the function of neurons in the brain. But to do those experiments, we needed new capabilities compared to what existed in the world before.”
The need for those additional capabilities led to the creation of the device, which the team has fittingly called MouseGoggles.
While scientists have tried using video imagery to map the reactions inside the brains of mice before, the light and sound produced by conventional means can actually interrupt the experiment being conducted or have no discernible effect on the mice at all. The thinking was that a virtual reality set-up might have a different effect.
“The more immersive we can make that behavioral task, the more naturalistic of a brain function we’re going to be studying,” said Schaffer.
Hacker ethos
To build the MouseGoggles the researchers turned to off-the-shelf components, specifically the displays from smartwatches.
“It definitely benefited from the hacker ethos of taking parts that are built for something else and then applying it to some new context,” said study co-author Matthew Isaacson, who has previously made display systems for fruit flies. “The perfect size display, as it turns out, for a mouse VR headset is pretty much already made for smart watches. We were lucky that we didn’t need to build or design anything from scratch, we could easily source all the inexpensive parts we needed.”
When the team submitted their study along with the build specs of the googles to the journal, Nature Methods for publication, an anonymous reviewer suggested also adding a small set of cameras in each eyepiece so that the animals' pupils could be tracked, which they did.
Unlike human virtual reality headsets, the MouseGoggles don't allow freedom of motion for the rodents. Instead, the mice are strapped into the headgear and and walk on a ball-like treadmill while wearing them. The team says, however, that part of their next steps will be to develop mobile goggles that can ride along on the heads of larger rodents like rats or tree shrews.
Getting jumpy with it
In tests, the mice responded dramatically to VR clips of a dark shape moving toward them.
“When we tried this kind of a test in the typical VR setup with big screens, the mice did not react at all,” Isaacson said. “But almost every single mouse, the first time they see it with the goggles, they jump. They have a huge startle reaction. They really did seem to think they were getting attacked by a looming predator.”
Other tests used fluorescent tracking in the brain to ensure it was being properly stimulated by the goggles. Indeed, the researchers were able to observe activity in the primary visual cortex, which confirmed that the goggles were properly transmitting sharp images to the rodents' retinas. They also saw activity in the hippocampus, which showed that the mice were mapping their virtual environments correctly.
In addition to creating lighter, more mobile versions of the MouseGoggles, the team says it might also be interesting to create a system that stimulates more than just the visual sense.
“I think five-sense virtual reality for mice is a direction to go for experiments,” says Schaffer, “where we’re trying to understand these really complicated behaviors, where mice are integrating sensory information, comparing the opportunity with internal motivational states, like the need for rest and food, and then making decisions about how to behave.”
The research was accepted for publication and is now visible in Nature Methods.
Source: Cornell University
