Study explores how brain disruption may foster schizophrenia

Yale University researchers have discovered an innovative way to study how large brain systems are organized, an advance that has already provided insights into diseases such as schizophrenia.

The Yale team used a combination of neuroimaging, computational neurobiology, and pharmacological techniques to reveal functioning at both the cellular level and across larger brain regions.

In a paper in Proceedings of the National Academy of Sciences the week of Sept. 24, Yale scientists use this approach to show that a disruption of a particular signaling mechanisms within larger neural systems may be contribute to schizophrenia symptoms.

Understanding how salamanders grow new limbs provides insights into the potential of human regenerative medicine

By studying a real lizard-like amphibian, which can regenerate missing limbs, the Salk researchers discovered that it isn’t enough to activate genes that kick start the regenerative process. In fact, one of the first steps is to halt the activity of so-called jumping genes.

In research published August 23 in Development, Growth & Differentiation, and July 27 in Developmental Biology, the researchers show that in the Mexican axolotl, jumping genes have to be shackled or they might move around in the genomes of cells in the tissue destined to become a new limb, and disrupt the process of regeneration.

They found that two proteins, piwi-like 1 (PL1) and piwi-like 2 (PL2), perform the job of quieting down jumping genes in this immature tadpole-like form of a salamander, known as an axolotl - a creature whose name means water monster and who can regenerate everything from parts of its brain to eyes, spinal cord, and tail.

"What our work suggests is that jumping genes would be an issue in any situation where you wanted to turn on regeneration," says the studies’ senior author, Tony Hunter, a professor in the Molecular and Cell Biology Laboratory and director of the Salk Institute Cancer Center.

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Human Brains Develop Wiring Slowly, Differing from Chimpanzees

Research comparing brain development in humans and our closest nonhuman primate relatives, chimpanzees, reveals how quickly myelin in the cerebral cortex grows, shedding light on the evolution of human cognitive development and the vulnerability of humans to psychiatric disorders. Myelin is the fatty insulation surrounding axon connections of the brain.

Recent research by Chet Sherwood, associate professor of anthropology in Columbian College of Arts and Sciences, along with Daniel Miller, a former GW graduate student, and other colleagues, reveals this key difference in brain development between human and chimpanzee. The findings were recently published in the September 24th edition Proceedings of the National Academy of Sciences (PNAS).

In the article, Dr. Sherwood and co-authors write that the development of myelin from birth to adulthood in humans is protracted in comparison to chimpanzees. In humans, myelin develops slowly during childhood, followed by a delayed period of maturity beyond adolescence and into early adulthood. In contrast, in chimpanzees, the development of myelin already starts at a relatively more mature level at birth and ceases development long before puberty.

“These observations indicate that a marked delay in the development schedule of the human neocortex may play an important role in the growth of connections that contribute to our species-specific cognitive abilities,” wrote Dr. Sherwood and co-authors.

The developmental timing of myelination is important because it establishes connectivity among parts of the growing brain, which is essential to higher-order cognitive functions, such as decision-making and emotional regulation. These cognitive functions are known to mature relatively late in humans, after the time of adolescence. Also, this period of persistent myelin development during early adulthood in humans is a time of particular vulnerability to neuropsychiatric diseases, including schizophrenia, bipolar disorder, and depression.

(SD)

Georgia Tech Creating High-Tech Tools to Study Autism

Researchers in Georgia Tech’s Center for Behavior Imaging have developed two new technological tools that automatically measure relevant behaviors of children, and promise to have significant impact on the understanding of behavioral disorders such as autism.

One of the tools—a system that uses special gaze-tracking glasses and facial-analysis software to identify when a child makes eye contact with the glasses-wearer—was created by combining two existing technologies to develop a novel capability of automatic detection of eye contact. The other is a wearable system that uses accelerometers to monitor and categorize problem behaviors in children with behavioral disorders.

Both technologies already are being deployed in the Center for Behavior Imaging’s (CBI) ongoing work to apply computational methods to screening, measurement and understanding of autism and other behavioral disorders.

JoVE Article Shows Steps to Isolate Stem Cells from Brain Tumors

A new video protocol in Journal of Visualized Experiments (JoVE) details an assay to identify brain tumor initiating stem cells from primary brain tumors. Through flow cytometry, scientists separate stem cells from the rest of the tumor, allowing quick and efficient analysis of target cells. This approach has been effectively used to identify similar stem cells in leukemia patients.

"Overall, these tumors are extremely rare, with only around one in 100,000 people being diagnosed with a primary brain cancer," Dr. Sheila Singh, co-author and neurosurgeon from McMaster University, explains. "However, these tumors are the second most common malignancy in the pediatric population, and are behind only leukemia as the cancer with the highest mortality rate."

This publication is significant because it allows scientists to identify, purify, and study brain tumor initiating cells rapidly and without sample loss. Because these stem cells allow scientists to grow films in a petri dish, they serve as an effective model of a tumor expanding in the brain of a patient.

Making it easier to make stem cells

The process researchers use to generate induced pluripotent stem cells (iPSCs)—a special type of stem cell that can be made in the lab from any type of adult cell—is time consuming and inefficient. To speed things up, researchers at Sanford-Burnham turned to kinase inhibitors. These chemical compounds block the activity of kinases, enzymes responsible for many aspects of cellular communication, survival, and growth. As they outline in a paper published September 25 in Nature Communications, the team found several kinase inhibitors that, when added to starter cells, help generate many more iPSCs than the standard method. This new capability will likely speed up research in many fields, better enabling scientists around the world to study human disease and develop new treatments.

NYU Biologists Uncover Dynamic Between Biological Clock and Neuronal Activity

Biologists at New York University have uncovered one way that biological clocks control neuronal activity—a discovery that sheds new light on sleep-wake cycles and offers potential new directions for research into therapies to address sleep disorders and jetlag.

“The findings answer a significant question—how biological clocks drive the activity of clock neurons, which, in turn, regulate behavioral rhythms,” explained Justin Blau, an associate professor in NYU’s Department of Biology and the study’s senior author.

Their findings appear in the Journal of Biological Rhythms