Scientists locate mileage tracker inside the brain

Rats and mice have been used by scientists for neurological research for many years, and now, in a new study, scientists have for the first time been able to locate a sort of distance tracker inside the brain.

By making rats run inside a small, defined arena, researchers have been able to record the part of their brains which is known to be crucial for navigation and memory.

They discovered that a pattern became visible which worked like a mileage clock, and which kept ticking with every step the animals took. 

Rats and humans: More alike than you’d think

At the same time, an experiment was conducted on humans.

The test was essentially the same as the one for the rats and the results showed that the same clock can be found in the human brain.

It’s the first study which shows that the regular ticking of the so-called “grid cells” is connected to the correctly estimated distance travelled. The study was published in the “Current Biology” journal.

The map inside our minds

The lead researcher on this study, Professor James Ainge from the University of St Andrews says: “Imagine walking between your kitchen and living room. [These cells] are in the part of the brain that provides that inner map – the ability to put yourself in the environment in your mind.”
 
The study not only demonstrates exactly how the “internal maps” inside of the brain work, but also what happens when conditions change or something unexpected happens.

Changing the environment and hence disrupting the ticking of the cells, has had a negative effect on both humans and rats and led to them wrongly estimating the distance.

Factors that would cause such a disruption in real life would for example be reduced visibility, such as in darkness or fog.

When those occur our “mileage counter” is no longer as reliable and it becomes much more difficult to estimate the distance travelled.

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Rats are commonly used in scientific research, but why?

Even though rats have been used in scientific research for over 200 years now, there is more to be discovered about them and, therefore, further methods for testing.

Additionally, the fields they used in have evolved and developed further over time.

For instance, in the early days of rat studies, they were used to understand human physiology and medicine by experimenting with oxygen and food deprivation.

Approximately 100 years later, the first rat mazes were built which aimed to assess their intelligence.

Furthermore, rat DNA has been and continues to be evaluated.

One famous project being the Rat Genome Sequencing Project Consortium, led by the US Baylor College of Medicine – with its findings demonstrating that most of the genes in humans linked to human disease have counterparts in rats.

Exploring these more would enable scientists to develop more accurate models of disease in humans.

Findings may be useful for Alzheimer’s diagnostics 

Scientists believe that apart from demonstrating how our brains allow us to navigate, this research and its findings may be useful when it comes to diagnosing Alzheimer’s Disease.

“The specific brain cells we’re recording from are in one of the very first areas that’s affected in Alzheimer’s,” said Prof. Ainge.

“People have already created [diagnostic] games that you can play on your phone, for example, to test navigation.

“We’d really be interested in trying something similar but specifically looking at distance estimation.” 

Studies on rats don’t always translate to effective therapies for humans, so whether this research will be useful for diagnostics cannot yet be confirmed.

However, it could be a major advancement in studying this disease, which is affecting an increasing number of people – and maybe, one day, these studies prove helpful in combating it.

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