University of California-Irvine neurobiologists have discovered a protein complex in neurons that is essential to long-term memory formation and is also corrupted in the brains of people with some developmental disabilities such as autism.

This complex is corrupted by the mutation of a specific protein molecule, and replacing that mutated molecule in laboratory mice restores their long-term memory — suggesting a possible gene therapy for humans, the researchers reported. Protein complexes access genes — portions of DNA — and turn them on and off at the right time to enable neurons in the brain to work properly, said Marcelo Wood, associate professor at UCI’s Center for the Neurobiology of Learning and Memory and director of the Interdepartmental Neuroscience Program.

Wood’s lab has identified nBAF as the protein complex needed for long-term memory. That protein complex is found only in neurons. When nBAF is corrupted by a mutation of its gene-encoding molecule baf53b, it can no longer perform the role of “nucleosome remodeling,” the means by which nBAF accesses genes.

When UCI researchers replace mutated baf53b with non-mutated baf53b in lab mice, it leads to a functioning gene-accessing nBAF ­protein complex and results in the return of their long-term memory, Wood said.

This research furthers the science of epigenetics, which has to do with gene access and gene function without a change to DNA coding. Cognitive impairments in learning and memory and neurodevelopmental disorders once thought to be genetic may be epigenetic. The emerging field of epigenetics — changes to the expression of genes without any changes in their underlying DNA coding — suggests that the environment and the things we’re exposed to can alter our gene function without changing our genetics. Epigenetics is why one twin, in a set of identical twins who share the same DNA, might get autism, cancer or another disorder, while the other one doesn’t, Wood said.

Science Now

First engineered blood vessel is implanted

A 62-year-old Virginia man with kidney failure received the first genetically engineered blood vessel in the United States, a vein that may improve his dialysis treatments and pave the way for future tissue transplants.

The operation at Duke University Hospital in Durham, N.C., marked the first time doctors have implanted an “off-the-shelf” tissue graft in the United States. The vessel, grown with human cells on a mesh tube, has the potential to be widely used since it was cleansed of any lingering cells that may trigger an immune reaction, said the doctors who performed the surgery.

The vessel was implanted into the arm, giving doctors easier access when performing dialysis. If the procedure is successful, man-made human veins may be used in heart-bypass surgery.

“A blood vessel is really an organ — it’s complex tissue,” said Jeffrey Lawson, a vascular surgeon at Duke Medicine who helped develop the approach and performed the implant. “We start with this, and one day we may be able to engineer a liver or a kidney or an eye.”

Bloomberg News

Many parents aren’t sweating screen time

Among the zillions of decisions that parents make, it might seem that determining the appropriate amount of time young children can spend watching TV and playing on tablets and smartphones might be a big one.

But it turns out that’s not the case. Most parents of children younger than 8 don’t give the matter much thought, researchers from Northwestern University found. Just 31 percent of the 2,300 parents surveyed expressed concern about their children’s media and technology use, while more than 55 percent of parents said they are not worrying about the amount of time their children spend staring at screens much at all.

“It was completely surprising to me,” said Ellen Wartella, director of Northwestern University’s Center on Media and Human Development and the lead researcher on the study in an interview with the Los Angeles Times. “It’s a generational shift. What we are seeing is a generation of parents who recognize that what kind of content you are exposing your kids to matters more than how much.”

Los Angeles Times