Lab Mice Hooked in Virtual Reality with Sugar Water Rewards Aid Experts in New Long-Term Memory Discovery

When given virtual reality games and sugar water rewards, a few lab mice inadvertently assisted researchers in their new long-term memory discovery.

In a recent study, mice were given virtual reality (VR) games to play while their brain activity was being monitored.

This allowed researchers to investigate the neuroscience that underlies this concept.

It was discovered that a part of the brain not usually associated with memory retention can be crucial in determining what is remembered for a long time.

Lab Mice and Virtual Reality

Mice were set on top of a Styrofoam ball while they played the video game, giving them the ability to choose where they wanted to go in the virtual world.

Depending on which areas of the game they chose to explore, they encountered either an endless supply of sugar water, a meager amount of sugar water, or only a puff of air in the face.

The mice eventually learned where the best sugar water would be and when to mentally prepare for a puff of air to the face by using cues, such as sights, sounds, and smells as indicators of which reward they would receive.

For several weeks, mice were subjected to these tests until they began to move more slowly when they anticipated an air puff and at full speed when presented with high-sugar scenarios.

As they learned about the various situations in which a lot or just a little was given, they even developed an understanding of how much to lick the sugar water spout.

While this was going on, scientists examined the effects of inhibiting or activating various brain regions on a mouse's performance.

They had issues because they were unable to grasp the VR routes and where they could find the best rewards in the long and short term due to hippocampus inhibition.

The mice were still able to learn despite the anterior thalamus's inhibition, but they were unable to store what they had learned in long-term memory.

Brain Game

The anterior thalamus was stimulated, and the VR gaming mice began to perform better, remembering where the rewards were for longer periods.

It is common knowledge that really great things are easier to remember compared to uninteresting ones, which is where the genius of the mediocre sugar water reward comes into play.

Without any interference, mice tended to forget the location of even a few sugar water drops, yet once the anterior thalamus was prompted, they were able to recall it.

A similar comparison would be pitting a birthday dinner against the dinner from three Tuesdays ago, according to study co-lead Andrew Toader in a statement to Eureka Alert.

The researchers also used cutting-edge equipment that allowed them to simultaneously image particular parts of the brain to support their VR findings.

They were able to determine that the thalamus was biased only toward storing data about significant events, or the unlimited sugar water, by monitoring the activity of specific neurons over a period of months.

The hippocampus, in contrast, activated equally for both the excellent and average sugar rewards.

Mouse Model Findings

The mouse model revealed that the anterior thalamus may be more important than previously thought in determining what is forgotten and what can be remembered for weeks to come when it involves long-term memory.

According to senior study author and Rockefeller University neuroscientist Priya Rajasethupathy, the thalamus establishes steadily increasing long-range interplay with the cortex to stabilize such memories for long-term storage.

There is a lot more to learn about how this stabilization and selection take place.

The research team hypothesized that dopamine or adrenaline may be assisting the thalamus in determining whether a memory is significant.

Rajasethupathy acknowledged that more research is needed to determine whether the memory stabilization process is punctuated or continuous, whether it develops gradually over time or in a series of steps, IFLScience reported.

The study by Rajasethupathy, Toader, and several other scientists is published in the journal Cell.