First we need to know from our doctors if we have lost myelin as part of our stroke. If so then make sure you get a prescription for social interaction.
http://www.eurekalert.org/pub_releases/2012-11/uab-nfo110912.php
Animals that are socially isolated for prolonged periods make less
myelin in the region of the brain responsible for complex emotional and
cognitive behavior, researchers at the University at Buffalo and Mt.
Sinai School of Medicine report in Nature Neuroscience online.
The research sheds new light on brain plasticity, the brain's
ability to adapt to environmental changes. It reveals that neurons
aren't the only brain structures that undergo changes in response to an
individual's environment and experience, according to one of the paper's
lead authors, Karen Dietz, PhD, research scientist in the Department of
Pharmacology and Toxicology in the UB School of Medicine and Biomedical
Sciences.
Dietz did the work while a postdoctoral researcher at Mt. Sinai
School of Medicine; Jia Liu, PhD, a Mt. Sinai postdoctoral researcher,
is the other lead author.
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," Dietz says. "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 is the crucial fatty material that wraps the axons of neurons
and allows them to signal effectively. Normal nerve function is lost in
demyelinating disorders, such as MS and the rare, fatal, childhood
disease, Krabbe's disease.
T
his paper reveals that the stress of social isolation disrupts
the sequence in which the myelin-making cells, the oligodendrocytes, are
formed.
In the experiment, adult mice, normally social animals, were isolated
for eight weeks to induce a depressive-like state. They were then
introduced to a "novel" mouse, one they hadn't seen before; while mice
are normally highly motivated to be social, those who had been socially
isolated did not show any interest in interacting with the new mouse, a
model of social avoidance and withdrawal.
Brain tissue analysis of the socially isolated animals revealed
significantly lower than normal levels of gene transcription for
oligodendrocyte cells in the prefrontal cortex, a brain region
responsible for emotional and cognitive behavior.
"This research provides the first explanation of the mechanism
behind how this brain plasticity occurs," says Dietz, "showing how this
change in the level of social interaction of the adult animal resulted
in changes in oligodendrocytes."
The key change was that cellular nuclei in the prefrontal cortex
contained less heterochromatin, a tightly packed form of DNA material,
which is unavailable for gene expression.
"This process of DNA compaction is what signifies that the
oligodendrocytes have matured, allowing them to produce normal amounts
of myelin," says Dietz. "We have observed in socially isolated animals
that there isn't as much compaction, and the oligodendrocytes look more
immature. As adults age, normally, you would see more compaction, but
when social isolation interferes, there's less compaction and therefore,
less myelin being made."
She adds, however, that the research also showed that myelin
production went back to normal after a period of social integration,
suggesting that environmental intervention was sufficient to reverse the
negative consequences of adult social isolation.
The new paper, together with a report published earlier this year by
another group showing myelin changes triggered by social isolation
early in life will broaden investigations into brain plasticity, says
David Dietz, PhD, one of the paper's co-authors, an assistant professor
of pharmacology and toxicology at UB.
In addition, adds Karen Dietz, the work has implications for
future questions regarding MS and other myelin disorders. "This research
suggests that maybe recovery from an MS episode might be enhanced by
social interaction," she says. "This opens another avenue of
investigation of how mood and myelin disorders may interact with one
another."
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