Recovering memories forever forgotten, sometimes due to neurodegenerative diseases such as Alzheimer's, is one of the greatest medical challenges facing humanity. An experiment on mice published this Wednesday in Nature shows memory improvements in old mice given cerebrospinal fluid (CSF) from younger animals.
CSF bathes the mammalian brain and spinal cord. The brain improvement detected, the researchers shuffle, can be attributed to growth factors – certain proteins – that have been shown to restore the function of neuronal cells. The results demonstrate the potential rejuvenating properties of young CSF for the aging brain, the publication notes in a press release.
As the brain ages, cognitive decline increases along with the risk of dementia and neurodegenerative diseases. Understanding how growth factors affect the brain throughout life has shed light on potential treatments to slow brain aging.
CSF is part of the immediate environment of the brain, providing brain cells with nutrients, signaling molecules, and growth factors, but its role in brain aging is poorly understood.
Old mice regain memory
To test the possible rejuvenating properties of CSF, Tony Wyss-Coray and colleagues infuse CSF from young mice (10 weeks old) into the brains of old mice (18 months old). The treatment improves the memory function of old animals, the authors report.
CSF from young mice increases the stimulation of cells called oligodendrocyte precursors – which have the potential to regenerate oligodendrocytes (a type of neuronal cell) and myelin (a fatty material that protects nerve cells) – within the hippocampus, the center of brain memory.
The authors conclude that these results identify the protein FGF17 (short for 'fibroblast growth factor 17') as a potential rejuvenation factor for the aging brain.
"The study not only implies that FGF17 has potential as a therapeutic target, but also suggests that drug delivery routes that allow direct access to the CSF could be beneficial for the treatment of dementia," the researchers note.