Brain research has revealed that mice have imagination

The research authors said that future studies of this kind could lead to the discovery of ways to help restore or enhance brain function by understanding a person’s intentions, and perhaps could expand our understanding of amnesia.

The work builds on previous scientific discoveries revealing that deep within the brains of animals and humans they have their own global positioning system (GPS). This internal GPS is located in the hippocampus, an area that plays a key role in memory and imagination, and translates places and events into patterns of neurons firing, a signal that brain cells are communicating. These patterns are then stored in the brain and used to navigate the everyday world.

The specialized cells that do this work, known as place and grid cells, serve as crucial building blocks that allow us to remember the past and imagine the future. The three scientists who discovered the cells received the 2014 award Nobel Prize in Physiology or Medicine To reveal functions that are considered “essential to our existence”.

“We can lie in bed at night, close our eyes, and put ourselves in the past or future,” said Zhongxi Lai, lead author of the new paper and a postdoctoral fellow at the Howard Hughes Medical Institute, now based at the University of Beth. Israel Deaconess Medical Center in Boston.

Imagination is crucial to innovation, Lai continued. “Any invention occurs twice: in the mind of the inventor, and then in the real world.”

In a 1948 paper, then a scientist at the University of California Edward C. Tolman Assume that mice have an internal map of their environment. However, until the new study, researchers had been unable to prove that a rat could actually control that map and use it to think about a place different from where the rat was at that specific moment.

“This is a very important step,” said Gyorgy Buzsaki, a professor of neuroscience at New York University’s Langone Medical Center, who was not involved in the study. “The hippocampus has a reputation as the brain’s GPS. Many of us would like to know how [what happens there] Translated into steps.”

Although it makes sense that the initial signal to imagine a place would come from the hippocampus, Buzsaki said, it is “extremely difficult” to determine whether any action originates in one part of the brain rather than another. The authors of the scientific paper focused on place cells located in the hippocampus. Grid cells, the other important part of GPS, live in an area deep in the brain called the entorhinal cortex, which is located near the hippocampus.

How to read a rat’s mind

The experiments detailed in the Science paper required scientists to build from scratch machines capable of reading a mouse’s internal map and then translating it, to determine what the mouse is thinking at a given moment.

Lai began working on the project nine years ago after arriving at the institute’s Janelia research campus in Ashburn, Virginia. He eventually told his two co-authors of the paper — his advisor Timothy Harris, a senior fellow, and Albert Lee, a Howard Hughes Medical Institute investigator — that he had ideas that would allow them to test whether an animal could think.

It took just four to five years to build a real-time “thought detector” for mice, Lai said.

The researchers then had to design experiments that took into account the tasks the rodents could perform. Initially, each mouse had small electrodes implanted in 128 specific locations in its brain. The electrodes were then attached to a device that reads the mouse’s brain activity and learns the specific patterns that are generated as the mouse moves from one place to another. At each site, the mouse brain produced a unique pattern of different cells firing at varying levels of intensity.

The mouse was suspended with its feet touching a ball-shaped treadmill, allowing it to move across a virtual reality arena. As the mouse moved, electrodes recorded its brain activity.

The scientists had to train mice to run toward a visual cue in a virtual 2D arena: a bouncing tower-like object. When the rodents sensed the signal, they received a reward of sweetened water.

The machine had to be trained as well. The machine learned to read the mouse’s brain activity and translate it to specific locations in the virtual arena.

For the “teleportation” tests, the scientists then disconnected the treadmill from the virtual reality arena. Now the mouse can no longer use its feet to move itself around the arena. Instead, the mouse had to imagine a distant location to reach that destination and obtain the reward.

In the second test, the mouse again had to imagine a specific remote location, this time to move a virtual object to that location. Throughout the test, the rat remained in a fixed position in the arena.

“The amazing thing is they learn it so quickly,” said Lee, who now works at Beth Israel Deaconess Medical Center. He said the mice’s rapid learning suggests that it is relatively normal for an animal to think about a place other than its actual location.

While three of the four mice tested were able to perform the experiments, the fourth was not. There are several possible explanations for the IV’s failure, Lee said. For example, the mouse may have suffered some minor damage to the hippocampus.

“This is rather complicated [task]“Not every animal may be able to do this,” he said. “The fact that three out of four animals did this so well suggests that there is a very strong ability in mice to imagine remote locations.”