Dr. Francis S. Collins here discusses the National Institutes of Health's new initiatives. Among the many efforts now poised to change the future of health are those to harness the power of gene editing, expand the reach of cancer immunotherapy, map the human brain, and build a solid foundation for a more individualized approach to health care, often called precision medicine. But along with the bright promise of preventing, treating, and curing some of humankind’s most feared diseases come some crucial questions about how to ensure such breakthroughs are applied both ethically and equitably.
The human brain has changed dramatically since humans diverged from a common ancestor shared with chimpanzees and the other great apes. However, the genetic and developmental processes responsible for this divergence are not understood. Now, brain-like tissues grown from stem cells in a dish—cerebral organoids—offer the possibility to study the evolution of early brain development in the laboratory. Researchers have analysed human cerebral organoids through their development from stem cells to explore the dynamics of gene expression and regulation side-by-side with macaque and chimpanzee organoids.
Despite their potential, brain organoids still have some critical limitations. In a study presented this week at SfN, stem cell biologist Arnold Kriegstein and his team demonstrated that human brain organoids do not accurately recapitulate all aspects of development. After comparing cells from organoids to those from normally developing tissue, the team reports that organoids have altered gene expression patterns and lack the cellular diversity in found in the human brain. In this Q&A, Kriegstein discusses different aspects of his team's study, including its origins, implications, and ethical considerations.
A trend in recent years has been to develop MRI systems with higher magnetic field strengths to boost the signal intensity. However, higher magnetic fields introduce image distortions and additional costs. They also limit what the machines can be used for. For example, certain metal devices, such as tools used during heart procedures, can’t be used with high-magnetic-field systems because they heat up. Now, a team of researchers has modified a commercial MRI system with a magnetic field strength of 1.5 T to operate at 0.55 T while maintaining all the components needed for high quality imaging.
Researchers have discovered in mice how one of the few genes definitively linked to schizophrenia, called SETD1A, likely confers risk for the illness. Mice genetically engineered to lack a functioning version of the enzyme-coding gene showed abnormalities in working memory, mimicking those commonly seen in schizophrenia patients. Restoring the gene’s function corrected the working memory deficit. Counteracting the gene’s deficiencies also repaired neuronal circuit deficits in adult mice—suggesting clues for potential treatment strategies.
Researchers trained two groups of young rats and then tested the driving prowess of each. One bunch was raised in an "enriched environment" with toys, ladders, balls and pieces of wood designed to spark mental stimulation; another was reared in a standard, unexciting lab cage. Once inside a custom rat-operated vehicle, the animals would try to collect a reward by propelling their tiny car to the end of an enclosure. Ultimately, the rats who played with ladders, balls and toys were more adept at operating and steering the ROV, thanks to the neuroplasticity triggered by the enriched environment.
Visa problems have become common enough that the Society for Neuroscience created a program called Science Knows No Borders for this year's meeting. The program is aimed at helping scientists present their research even though they cannot attend. The Society for Neuroscience says fewer than a dozen scientists from Iran, Mexico and India participated in the Science Knows No Borders program this year, but an informal survey of more than a dozen poster presenters found that nearly all of them knew at least one brain scientist who had been kept away by a visa delay or denial. And this number doesn't include scientists who never made travel plans at all because they hold passports from a banned country.
In the past, some fully-paralyzed patients have been able to communicate by using their thoughts to move a cursor and select letters onscreen. However, this process was slow: the operation only allowed users to communicate at a rate three times slower than natural handwriting (39 characters per minute). Now, in new experiments, a volunteer paralyzed from the neck down imagined not a visual cursor but rather the physical movement required to write each letter of the alphabet with his arm. Eventually, a neural network trained with information from this brain activity was able to communicate the volunteer’s imagined sentences much more quickly, at a speed of 66 characters per minute.
Researchers at the RIKEN Center for Biosystems Dynamics Research in Japan have developed a new system for keeping tissue viable for long-term study once transferred from an animal to a culture medium. The new system uses a microfluidic device that can keep tissue from both drying out and from drowning in fluid. A proof-of-concept experiment showed that tissue explanted from the mouse brain remained viable after almost one month in culture, much longer than is possible with other microfluidic culturing methods. The method promises to improve research into organogenesis through long-term culturing and observation which is necessary for growing tissue and organs.
Last year, consumers spent nearly $2 billion on brain training apps, some of which claim to improve cognitive skills. However, evidence suggests you’d be better off spending more time exercising and less time staring at your phone. This year the World Health Organization released evidence-based guidelines on reducing risks of cognitive decline and dementia. Although it pointed to some systematic reviews that reported positive cognitive effects of brain training, the W.H.O. judged the studies to be of low quality. Overall, there is no long-term evidence of general improvement in cognitive performance when using the apps.
You wouldn’t know it just by gazing at its yellowish veins of matter, but the blob (so-called) is perhaps the most cunning brainless organism on the planet. The single-cell slime mold, which lacks a nervous system, has long baffled scientists for its ability to learn, pass knowledge to other molds and repair itself in minutes. Those scientists still don’t know how exactly to categorize this organism. But after stupefying generations of researchers, Physarum polycephalum—“many-headed slime”—made its public debut last Saturday at the Paris Zoological Park.
Could a predictive-text technology named GPT-2 write an article for TheNew Yorker? What if the automated writer was fine-tuned on magazine's digital archive? How would it react to the millions of polished and fact-checked words, many written by masters of the literary art? In calibrating GPT-2, the neural network categorized distinctive aspects of New Yorker prose—the words its writers tended to favor, the magazine’s rhythms, its distinctive style of narrative rhetoric, its voice—and the learning algorithm used these data to automatically adjust the neural net’s settings, so that its predictions leaned toward the magazine's locutions.
Speaker: Zhixin Lu (University of Pennsylvania) Title: "A putative mechanism for implicit learning in biological and artificial neural systems" Date: Thursday, October 31, 2019 Time: 12:30 p.m. Location: 1207 Energy Research Facility More info
Speaker: Michael Reiser (Janelia Research Campus) Title: "Connecting vision to behavior in Drosophila" Date: Friday, November 1, 2019 Time: 10:15 a.m. Location: 1103 Bioscience Research Building More info
The Brain Research Foundation is inviting eligible US institutions to nominate one faculty member to submit a Letter of Intent for the Fay/Frank Seed Grant Program. BRF provides start-up money for new and innovative research projects that have the potential to become competitive for an NIH grant or other external funding sources. Applications must be submitted through the UMD VPR's office. Materials due November 4, 2019.