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Can the memory performance of old mice improve again?
Photo: Evgenyi_Eg / iStockphoto / Getty Images
Memory capacity decreases with age and people become forgetful.
Scientists have been working for a long time to slow down the decline in memory and possibly even reverse it.
A research team from the USA could now have succeeded: they improved the memory performance of older mice - with the help of the brain fluid of young conspecifics.
The results were published in the journal »Nature«.
The cure: a brain infusion
For the experiment, the team used the so-called cerebrospinal fluid of young mice, the cerebrospinal fluid.
This clear bodily fluid surrounds the brain and spinal cord and is the plasma of the central nervous system.
It is essential for normal brain development.
But the older mammals get, the more the liquor loses its effectiveness.
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However, the experiment showed that a direct brain infusion with the cerebrospinal fluid of young mice improved the memory function of older mice again.
Presumably, the conductivity of the neurons would increase, improving the process by which memories are formed and recalled.
The team also suspects a specific protein in the liquid improves performance.
"This is very exciting from a basic science perspective, but also in terms of therapeutic applications," says Maria Lehtinen, a neurobiologist at Boston Children's Hospital in Massachusetts.
How do you test the memory of mice?
But how can you even measure memory in mice?
The researchers tried to give aging mice an experience they would remember.
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They gave 20-month-old mice three small electric shocks to the foot, accompanied by multiple flashes of light and sound.
The mice should make an association between the lights and the shock.
The researchers then injected eight mice with the liquor from mice half their age.
A control group of ten old mice received an artificial cerebrospinal fluid.
The removal of the liquid proved to be difficult in this process, because any contamination with blood would have rendered the liquor unusable.
Then, after three weeks, the treated mice were exposed to the same sounds and lights, but without the shock.
Almost 40 percent of the mice given the brain fluid from young conspecifics remembered the shock and froze in fear.
This was the case for 18 percent of the mice with artificial CSF.
It is possible that the liquor of young conspecifics could restore some of the declining abilities of the aging brain.
"This means the brain is still malleable and there are ways to improve its function," says Tony Wyss-Coray, a neuroscientist at Stanford.
"All is not lost."
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