The brains become stiff with age, just like muscles and joints, scientists say.
New studies show that increasing brain stiffness with age causes brainstem dysfunction.
But scientists are demonstrating ways to restore older stem cells to a younger, healthier condition that may affect future treatment for multiple sclerosis (MS).
The team, based at the Wellcome-MRC Stem Cell Institute at Cambridge (University of Cambridge), studies the brains of old and young rats to understand the effects of age-related hardening on oligodendrocyte progenitor cells (OPC).
These cells are vital for maintaining normal brain function and for the regeneration of myelin, a fatty tissue that surrounds the nerves and is damaged by multiple sclerosis (MS). [1
Dr. Kevin Chal, who led the study, said: "We were fascinated when we grew young, functioning rat brain stem cells on solid material, the cells became dysfunctional and lost their ability to regenerate and actually began to function as aged cells.
"What was particularly interesting, however, was that when old brain cells are grown on soft material, they begin to function as young cells – in other words, they are rejuvenated. ”
In a study published in the journal Nature, researchers transplanted older OPCs from adult rats into the soft, spongy brains of younger animals.
They discovered that older brain cells were rejuvenated and began to behave like younger, more energetic cells.
The researchers then developed new materials in the laboratory with varying degrees of stiffness and used them to grow and examine rat brain stem cells in a controlled environment.
The materials are designed to have a similar softness to both young and old brains.
To understand fully why the softness and stiffness of the brain affect cell behavior, researchers tested Piezo1, a protein found on the cell surface that informs the cell whether the environment is soft or hard.
"When we removed Piezo1 from the surface of an aged brain stem cell, we were able to entice the cells to adopt a soft environment, even when growing on solid material," says Professor Robin Franklin, who leads the study.
Dr. Susan Colhaas, Director of Research The MS Society, which funds part of the study, stated: "MS is ruthless, painful and disabling, and treatments that can delay and prevent the accumulation of damage over time are desperately needed.
"The findings of the Cambridge team on how the brain ages stem cells and how this process can be altered have important implications for future treatment as it gives us a new purpose to address aging and MS issues, including how to potentially regain lost function in the brain. “