The brains of socially isolated animals make less myelin, the critical material that wraps the axons of neurons.The researchers say the findings, reported in the journal Nature Neuroscience, indicate that neurons aren’t the only brain structures that undergo changes in response to an individual’s environment and experience.
The paper notes that changes in the brain’s white matter, or myelin, have been seen before in psychiatric disorders, and demyelinating disorders have also had an association with depression. Recently, myelin changes were also seen in very young animals or adolescents responding to environmental changes.
“This research reveals for the first time a role for myelin in adult psychiatric disorders,” says Karen Dietz, a research scientist in pharmacology and toxicology in the University at Buffalo School of Medicine and Biomedical Sciences. “It demonstrates that plasticity in the brain is not restricted to neurons, but actively occurs in glial cells, such as the oligodendrocytes, which produce myelin.”
Myelin allows neurons to signal effectively. Normal nerve function is lost in demyelinating disorders, such as multiple sclerosis (MS) and the rare, fatal, childhood disease, Krabbe’s disease.
This paper reveals that the stress of social isolation disrupts the sequence in which the myelin-making cells, the oligodendrocytes, are formed.