Conventional wisdom tells us that a mammal brain dies minutes after it stops receiving oxygen. But a recent study, published in Nature on Wednesday, brings into question our current definitions of life and death.
Researchers from the Yale School of Medicine successfully revived cellular activity in the brains of pigs slaughtered for meat. The brains did not regain consciousness, but the blood vessels resumed functioning and certain cells restarted metabolic activities, including absorbing oxygen and producing carbon dioxide. The researchers also measured electrical activity, although it was not a pattern that signifies consciousness.
“It is not a living brain, but it is a cellularly active brain,” neuroscientist Nenad Sestan, who led the study, told The New York Times.
To conduct the experiment, researchers removed the brains of 32 pigs four hours after they had been slaughtered for meeat. In a move that may seem straight out of science fiction, they then hooked the organs up to a system called BrainEx, which circulated a synthetic blood through the brains for a total of six hours.
Carrying oxygen and other nutrients, the solution also contained chemicals meant to block nerve signals, which served two purposes. First, it helped protect the cells from deteriorating, a process called excitotoxicity. And second, as an extra precaution, the researchers wanted to eliminate the (very small) possibility of a brain regaining consciousness. They were ready to end the experiment and administer anesthesia in the event such activity was detected.
As news coverage made clear, the work is preliminary and has no direct implications for medicine. But it does present new possibilities for understanding how to treat patients who have suffered massive strokes or other traumatic brain injuries.
It also raises unsettling ethical questions. Currently, a person is legally dead if they lose all brain function. The possibility of reviving a brain-dead patient might have a big impact on organ donations. If a person has a heart attack, for example, medics may face more complicated decisions on whether they should continue trying to revive the patient or if they should prepare for organ donation.
Also in the news:
• A new type of gene-therapy for infants born without a functioning immune system has successfully treated eight babies in a clinical trial at St. Jude Children’s Research Hospital and the University of California, San Francisco (UCSF) Benioff Children’s Hospital. The treatment uses a modified version of HIV to deliver a gene that restores immunity in infants born with a form of severe combined immunodeficiency, called SCID—X1. Fewer than 100 children, mostly boys, are born with the rare fatal disease in the U.S. each year. Since the 1990s, bone marrow transplant has been the standard treatment for SCID, but it requires a donor match, lifelong monthly infusions, and puts the recipient at risk for leukemia. The new St. Jude treatment is expected to be permanent and to carry less risk of developing blood cancer. Study results were published in the New England Journal of Medicine on Wednesday. Since the paper was prepared for publication, two more infants have also successfully undergone the new treatment, and St. Jude has penned a licensing agreement with the small gene therapy company Mustang Bio in the hopes of commercializing the procedure. (NPR)
• Astrochemists announced this week the observation of our universe’s most ancient type of molecule — helium hydride — in a 600-year-old planetary nebula about 3,000 light years away. First born as the hot ions produced during the Big Bang began to cool and form bonds, helium hydride had been synthesized in the lab nearly a century ago, but its detection in the wild proved elusive, leading some researchers to believe it had been lost to space. According to a paper published Wednesday in the journal Nature, the team detected the characteristic frequencies of light emitted by the molecule using a specialized lab built into a Boeing 747SP aircraft known as the Stratospheric Observatory for Infrared Astronomy. Flying at an altitude of 45,000 feet, the spectrometer onboard the plane could detect light emissions that would be obscured from ground-based detectors by water vapor in the Earth’s atmosphere. The light emission associated with helium hydride was spotted coming from a young planetary nebula known as NGC 7027 with a hot, dense central star. “The lack of evidence of the very existence of helium hydride in the local universe has called into question our understanding of the chemistry in the early universe,” Rolf Güsten, an astronomer at the Max Planck Institute for Radio Astronomy and the study’s lead author, told The Guardian. “The detection reported here resolves such doubts.” (The Guardian)
• A new study suggests that even in the far reaches of the seemingly pristine Pyrenees mountain range, microplastics — lots of them — are blowing in the wind. At a meteorological station in southwestern France, 4,500 feet above sea level and 60 miles from the nearest city, researchers collected an average of more than 350 pieces of plastic per day on a surface just one square meter in area. “The number is astounding,” said Steve Allen, who contributed to the work. The collected plastic — worn down bits of packaging materials, plastic bags, cloth fibers, and similar materials — is thought to have originated in cities up to hundreds of miles away. Assuming such particles rain down at comparable rates in other parts of the country, France may be blanketed with some 2,000 tons of microplastics every year. Although the tiny particles are known to be pervasive in soil, oceans, and bodies of fresh water, Allen sees the windborne microplastics as “a brand new [type of] pollution” that could present new threats: They can probably be inhaled by humans, he says, and once they get into the atmosphere, they are virtually impossible to clean up. (NPR)
• For thousands of years, the Cofan people of Ecuador have made their home in the rainforest, relying on its resources for food, shelter, and medicine. According to the United Nations Declaration on the Rights of Indigenous Peoples, their ability to continue this way of life should be protected. With their territory now falling within a national park, however, the Cofan in reality lack autonomy over their land. As their community faces increasing threats from illegal mining, logging, and poaching, they and other indigenous peoples are taking action. Working with various non-governmental and indigenous organizations, the Cofan two years ago began using GPS devices, along with a drone and hidden cameras, to monitor and map the forest with the goal of using the data they collect to apply for an official title to their land. Already in 2018, they gathered enough evidence to prove that miners granted legal concessions by the government were operating outside of their permitted zones, resulting in water pollution and other environmental damage. “Today, we feel stronger and more powerful and able to say that the Cofan are warriors,” said Edison Lucitante, the president of the community of Sinangoe. “We won the trial. We beat the government. We’re going to keep going.” (Pacific Standard)
• As political and trade tensions continue to percolate between China and the administration of U.S. President Donald J. Trump, the research and academic communities are finding themselves increasingly affected by the fallout. In some cases, U.S.-based universities have been nudged to take punitive actions against foreign scientists described by the journal Nature as “breaking rules” related to projects that receive funding from the National Institutes of Health. The sanctions are being undertaken in response to a letter from NIH chief Francis Collins earlier this year, which called on American universities to be on the lookout for “foreign entities” interfering in NIH-funded research. Other federal agencies have been scrutinizing and updating rules surrounding interactions with foreign researchers, and the State Department has revised rules for issuing visas to Chinese students seeking to undertake graduate studies in the U.S. — and even the issuing of visas to Chinese nationals looking to attend scientific conferences have been stymied or slowed recent months. The moves prompted a concerned letter to Nature last month from groups representing Chinese-American researchers, who argued that scientists of Chinese descent working in the U.S. were in real danger of “scape-goating, stereotyping, and racial profiling.” (Nature)
• And finally, the comparatively sleepy realm of archaeology is still reeling from a #MeToo controversy that erupted last Thursday during an annual professional meeting in New Mexico, and continued into this week with angry letters and charges of failed leadership. At the center of the dustup was David Yesner, a former archaeologist at the University of Alaska in Anchorage (UAA), whose recent retirement was accompanied by multiple charges of “sexual discrimination, assault, and harassment,” according to Science magazine. After a subsequent investigative report commissioned by the university and published last month found nine of the charges to be credible, Yasner was banned from the UAA campus, and when he showed up at the Society for American Archeology meeting in Albuquerque — a meeting also being attended by some of his accusers — discord ensued. Yesner was eventually ejected from the proceedings not by SAA organizers, but by a freelance journalist who was scheduled to speak at the conference about, yes, sexual harassment. The SAA’s initial response: banning the journalist from the rest of the meeting. A series of open letters, public resignations, and Twitter disputes followed, and while the SAA had begun a more earnest effort at apology and self-reflection by mid-week this week, critics suggested the organization was still waffling over details related to what had transpired at the conference — and what it would do to reform itself going forward. (Science, KTVA)