Scientists talked about the role of the white matter of the brain in the development of neurodegeneration

Researchers at the University of Cambridge have found that local damage to the white matter of the brain can trigger a chain reaction in the gray matter, forming signs of neurodegenerative diseases. This was reported on April 22 in the journal Medical Xpress.

Until now, the medical community has been dominated by the idea that Alzheimer's and Parkinson's diseases are primarily associated with changes in gray matter, a collection of neural information processing centers. The white matter forming the pathways between these centers was considered as a passive component. A new study refutes this view.

A group led by Ragnhildur Tora Karadottir, a professor from the Cambridge Institute of Stem Cells, reproduced local damage to myelin, the main component of white matter, in a strictly limited neural circuit. Observation of the consequences yielded unexpected results: even a small lesion of myelin caused a pronounced response in a remote area of gray matter — a decrease in neural activity, activation of microglia (immune cells of the brain) and loss of interneuronal connections.

It is crucial that these changes are reversible. After the restoration of myelin, neural activity returned to normal, interneuronal connections returned, and the inflammatory response subsided. This means that inflammation of the gray matter — traditionally considered harmful — is actually part of the repair process.

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When the researchers artificially blocked the regeneration of myelin, the gray matter response did not resolve and the inflammation became chronic. According to the authors, it is the unsuccessful regeneration of myelin that may be one of the key mechanisms of sluggish inflammation characteristic of neurodegenerative diseases.

"Focal lesion of white matter is not only a local event. It is able to trigger a coordinated response in the associated gray matter, and this response is not just damage, but an attempt by the brain to recover," Karadottir said.

Alasdair Coles, Professor of Clinical Neuroimmunology, added that therapy aimed at enhancing myelin regeneration can slow the progression of a wide range of brain diseases.

On April 15, Science Daily magazine reported on the association of mental activity with the risk of Alzheimer's disease. According to the study, continuous learning, including reading, writing and learning foreign languages, is associated with a 38% reduction in the risk of developing the disease.