Alzheimer’s brain disease is the most common form of dementia worldwide, accounting for two out of three cases.
In patients, the brain cells gradually die, causing mental functions such as memory, orientation and judgment to deteriorate until the patient dies.
Until now, medicine was mainly concerned with developing drugs to slow down the damage to the brain.
But now researchers at Stanford University in the US may have found a way to prevent people with dementia from losing their memory.
By injecting spinal fluid from young mice into older mice, the scientists were able to slow down the memory loss that usually occurs as the rodents approach the end of their lives.
Spinal fluid pumped into brain
The research has been published in the scientific journal Nature and is based on a 2014 study, when the same team proved that old mice get better memory and orientation when they inject blood from young mice.
This time they want to know whether a dose of young spinal fluid in older mice would have a similar positive effect on memory.
To do this, they collected a total of 10 microliters of spinal fluid (about a fifth of a water droplet) from hundreds of ten-week-old mice.
They did this by making a hole in the necks of the mice and sucking a microscopic amount of fluid from a cavity near the brain.
The researchers then drilled a hole in the skulls of the older mice and transferred the young spinal fluid to the brain via an implanted pumping mechanism.
Mice hear a beep
A few weeks after the procedure, the mice were exposed to a number of stimuli (a beep and a flash of light), which they had learned to associate a few weeks earlier with an electric shock.
Younger animals store memories of these painful experiences, which last for weeks or months, but older mice cannot.
Unlike the younger mice, the untreated, older mice did not react to the sound and light announcing a shock by stiffening.
But the older mice that had been given the young spinal fluid did. When they saw the flash of light or heard the beep, they instantly stiffened.
According to the researchers, this proves that the treated mice preserved the memories of the shocks much better than the untreated mice.
Genetic tests of the mice showed afterwards that the young spinal fluid mainly had a positive influence on a number of specialized cells in the brain, so-called oligodendrocytes, which are important for memory.
Furthermore, it appeared that the oligodendrocytes reacted particularly positively to the protein FGF17 from the spinal fluid, which normally disappears with age.
Usable medicine is still a long way off
Success in improving memory with the protein FGF17 could become very important for treating dementia.
If a synthetic substance similar to FGF17 can be produced, the memory loss associated with the dreaded disease may be inhibited or prevented.
However, it will take some time before this eventually becomes a reality. Tests have only been done on mice, and there are no tests on humans yet.
In addition, the researchers still have to find out how the drug can get to the right place in the brain in a safe way.