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.
Ellen Goldbaum | EurekAlert!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine