A mammal which can shrink and regrow its brain could unlock future treatments for human brain conditions like Alzheimer’s.
European researchers are studying the shrew which shrinks its brain in winter, then grows it back in summer.
Study first author Cecilia Baldoni, a postdoctoral researcher from Germany’s Max Planck Institute of Animal Behaviour, said brain shrinkage in humans was typically a sign of disease, like Alzheimer’s.
“But shrews can shrink their brain without compromising function or causing damage,” Dr Baldoni said.
“Shrews could become a model system for exploring potential pathways for medical treatment of human brain disease.”
She said common shrews were one of only a handful of mammals known to flexibly shrink and regrow their brains.
Dr Baldoni said their study, using non-invasive MRI, scanned the brains of shrews undergoing shrinkage, and identified water as a key molecule involved in the phenomenon.
“Our shrews lost nine percent of their brains during shrinkage, but the cells did not die. The cells lost water.”
She said, normally, brain cells that lost water became damaged and ultimately died, but in shrews the opposite happened.
“The cells remained alive and even increased in number.”
Associate John Nieland, an expert in human brain disease at Aalborg University, Denmark, said the findings opened up potential pathways for the treatment of human brain disease.
“We see that brain shrinkage in shrews matches closely what happens in patients suffering from Alzheimer’s, Parkinson’s and other brain diseases,” Dr Nieland said.
He said the study also showed that a specific protein known for regulating water, aquaporin 4, was likely involved in moving water out of the brain cells of shrews.
“We see this same protein present in higher quantities in the diseased brains of humans too.”
Read the full study: Programmed seasonal brain shrinkage in the common shrew via water loss without cell death.
