This is a good piece, readers: When Europeans Were Slaves: Research Suggests White Slavery Was Much More Common Than Previously Believed Editor’s note (3/21/20): For an update on this story, visit: Why is a 16-year-old book on slavery so popular now? A new study suggests that a million or more European Christians were enslaved by […]
Every day, the human body replaces billions of cells, flushing out the old and generating the new, healthy ones. The average lifespan of a red blood cell is just under four months, while skin cells last about a month, and those in the intestinal lining exist for just a few days. This turnover is the default, but there’s one part of the body in which humans and other mammals don’t seem geared toward generating new cells: the brain.
Aging and damaged brain cells, or neurons, can cause memory problems and limit the brain’s ability to recover from illnesses. Some scientists have posited that if we could just turn on the ability to make new neurons in the brain—a process called neurogenesis—some of these deleterious changes might be reversed. But a new study suggests neurogenesis may be more destructive than we thought, adding weight to a countertheory that our brain’s apparent limitation is actually an evolved protection.
“Birds, reptiles, fish: they all have widespread neurogenesis throughout their forebrains throughout life,” says Benjamin Scott, the study’s senior author and an assistant professor at Boston University. “It’s really in mammals where we see this restricted.”
In the new paper, published today in Current Biology, Scott and his colleagues analyzed the brains of Zebra Finches, small songbirds that undergo neurogenesis throughout their life. The researchers wanted to know how adult neurogenesis affected surrounding brain tissue, so they used an electron microscope to watch how new neurons reach their destination in the brain. Researchers had previously assumed neurons might follow structures in the brain called glial scaffolds, which guide neurons to the right place during development. But Scott and his team observed that the new neurons tunneled straight through older neural pathways and that the new brain cells were more rigid than “squishy” mature neurons.
“They’re just sort of everywhere in the tissue,” Scott says of the new neurons. “They’re touching all the mature cells. They’re right in the middle of all of the action.”
Because adult brains are done growing, they don’t have room for new structures, so the tunneling wasn’t a complete surprise to researchers. Still, understanding the destructive side of neurogenesis—doing away with older paths through the brain to make new connections—could help researchers understand why mammals limit this ability in adults.
“One of the things that this study has revealed to us is that, as the new neurons move through the brain, they seem to be pushing or deforming the tissue,” Scott says. “You could imagine that they might be altering the circuit, breaking connections that are the basis of stored memories.”
Humans and other mammals might have evolved to limit adult neurogenesis to preserve important long-term memories, he and his colleagues speculate. But because mammals and birds are so different, it’s hard to know if the same tunneling process happens in mammalian brains, too.
“The human and bird forebrains have different organization patterns…, so some caution is called for in extending parallels to the level of brain circuits and cells,” says Eliot Brenowitz, a neurobiologist at the University of Washington, who was not involved in the new study.
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Scientists have long studied songbirds, such as Zebra Finches, to understand the brain. Chris Ison/Alamy
After a rare disease diagnosis left her partially paralyzed, Marion Jones worked her way back from being reliant on a wheelchair to running marathons.
Jones credits her recovery to the doctors and therapists in Boston who helped her relearn how to walk — and eventually run again.
Now, she is running the Boston Marathon as a full-circle tribute to the hospital that treated her, and in support of the rare disease community.
In 2020, Marion Jones was living in Boston working for a green energy company, when she decided it was time to see a doctor. For about a year, she had been experiencing nagging health problems.
“For me, it started to show up as this burning sensation in various parts of my body. It would maybe last for 10 seconds, and then it would migrate to another part of my body,” she said.
When she began to have excruciating back pain, she made an appointment.
The first doctor she saw couldn’t explain the symptoms, but a second doctor suspected multiple sclerosis, or MS. An MRI quickly ruled MS out, and Jones returned to her normal life.
But after developing a headache that lasted for several months, a friend convinced her to visit the emergency room. A doctor prescribed a muscle relaxer and released her, but just 72-hours later, Jones found herself back in the hospital — this time with difficulty moving the right side of her body.
It was there at Beth Israel Lahey that Jones received news that would change her life forever. She was diagnosed with neuromyelitis optica, or NMO — a rare, autoimmune disorder that primarily affects the optic nerves and the spinal cord.
Sometimes referred to as the “cousin of MS”, NMO typically causes severe, rapid, and destructive attacks on the optic nerves and spinal cord, and can lead to permanent vision loss or paralysis.
Things quickly spiraled for Jones. A flare-up caused her to experience partial paralysis, and doctors admitted her to the intensive care unit of the hospital.
Jones was admitted into the ICU after a rare disease diagnosis left her temporarily paralyzed.
Marion Jones
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But Jones, who had a limited ability to walk and care for herself, needed more specialized care and was eventually admitted to the Encompass Rehabilitation Hospital of New England, a hospital that specializes in inpatient rehab.
For Jones, who was an avid runner prior to her diagnosis, it was a particularly devastating blow.
“In 2019, I had run 35 five Ks in 35 weeks … to not being able to walk or get myself to the bathroom. It was just something that I had never thought would happen to me,” Jones said.
Jones, who had no family in Boston, said the doctors and therapists at Encompass set her on a path towards recovery from day one.
“They really became family for me. In the absence of my family. They were so patient,” Jones said.
Dr. Daniel Lyons, the medical director of Encompass Rehabilitation Hospital of New England, was a member of that team.
“Marion had a situation where her autoimmune illness affected the cervical spinal cord injury. So essentially … she had a spinal cord injury. She had lost her strength in her arms, her legs. There was sensory loss. She also had a lot of pain and muscle tightness from the spinal injury,” Lyons said.
Jones was forced to use a wheelchair after she lost her ability to walk following a diagnosis of NMO. Marion Jones
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Jones’ rehab schedule was grueling — three hours of intense therapy every day. But Lyons said the work paid off. “She made an incredible amount of progress from the time she came into the rehab hospital, she was using a wheelchair, non ambulatory. [In] a relatively short time, she had progressed through walking in parallel bars to a walker, and she was able to walk short distances with a walker when she left inpatient rehab hospital.”
Outpatient therapy continued for Jones, and it was during one of those sessions that her therapist challenged her to run on a treadmill. It was difficult for Jones, and she says she could only run for about 30 seconds, but it reawakened her desire to run again.
“After that session, I got home and I got on the bike path and I said, ‘I’m going to see if I can run for a minute,’” Jones said. “As the weeks progressed, the minute became a half a mile, and that half a mile became a mile. And so that’s where I started, really just getting in the mindset of running again.”
Eventually, she regained her form. Jones says she never set out to run a marathon, but that’s where her path led her. Since her diagnosis, Jones has run in six marathons.
On the surface, it appeared as though Antoinette Del Rio was a successful 20-something. She had a flourishing career in advertising, took frequent vacations, and enjoyed an active social life.
But Ms. Del Rio was drinking too much, using weed as a coping mechanism, and spending weekends holed up in her New York City apartment. She had also fallen into debt from impulsive overspending and frequently fought with her friends.
Soon she began to notice a troubling pattern in all of her relationships: They felt either euphoric or devastating, with no middle ground. A seemingly small conflict could cause her to “completely lash out without thinking of any of the consequences,” said Ms. Del Rio, now 33. Sometimes she was so angry that she would pull out her hair or dig her nails into her skin “as hard as possible.”
In 2022, her primary care doctor pieced it all together: Ms. Del Rio was showing telltale symptoms of borderline personality disorder, or B.P.D., a condition characterized by volatile relationships and emotions, alongside reckless behavior and an empty sense of self.
B.P.D. is challenging to effectively treat, which can “scare the pants off therapists,” said Dr. Lois W. Choi-Kain, director of the Gunderson Personality Disorders Institute at McLean Hospital in Belmont, Mass. But people can — and do — get better, she added, even those with additional issues like substance use and disordered eating.
Dr. Choi-Kain said that she had seen people who were very ill develop the skills to “feel good about themselves, and then be able to manage a relationship differently,” she said.
What is a borderline personality?
Mental health practitioners define borderline personality disorder as a pattern of instability in someone’s relationships, self-image, and emotions.
People with B.P.D. have a tendency to do things without thinking, sometimes engaging in activities like reckless sex, substance abuse, or self-harm, which is often what leads them to treatment.
It is estimated that B.P.D. affects 1.6 percent of the population; it isn’t considered by mental health professionals to be rare, yet the disorder is often misdiagnosed at first because some of its symptoms can be mistaken for other conditions, such as bipolar disorder, depression, and attention-deficit hyperactivity disorder.
These conditions can also overlap with B.P.D., which further complicates the diagnosis. In fact, in 1938, B.P.D. was initially described as “borderline” by the psychoanalyst Adolph Stern because it borders on other conditions.
What are the signs and symptoms?
B.P.D. symptoms can include inappropriate outbursts of anger, feelings of emptiness, and desperate efforts to avoid feeling abandoned — for example, continually seeking reassurance or “testing” people to see if they will stay, said Sara Masland, an associate professor of psychological science at Pomona College and an expert in personality disorders.
Other features of B.P.D. include volatile relationships, an unclear sense of self, a tendency to self-harm, recklessness, and suicidal behavior. (Studies have found that as many as 10 percent of people who had B.P.D. died by suicide — a number far greater than that of the general population.)
Patients must have at least five symptoms to be diagnosed, according to the diagnostic manual used by mental health practitioners.
One of the defining features of borderline personality disorder is hypersensitivity — most people swing back and forth between being anxious or fearful of being criticized or disliked, and angry or paranoid when they feel as though people are rejecting them, Dr. Choi-Kain said.
One minute a patient might feel fine, then depressed, then intensely angry. This can lead to relationships that are full of conflict and devoid of peace, harmony, consistency, or depth, said Dr. Frank Yeomans, clinical professor of psychiatry at Weill Cornell Medical College, who has focused on the treatment and research of personality disorders for decades.
When things seem perfect, “you’re in heaven,” Dr. Yeomans added. But “as soon as there’s any flaw in what was nice, you go from heaven to hell.”
Despite the chaos in their personal relationships, people with B.P.D. often find it difficult to be alone, the experts said. This is partly because they don’t have a sense of who they are independent of other people.
“Oftentimes people with B.P.D. will over-rely on relationships to understand who they are, and that can make the relationship instability even more tenuous,” Dr. Masland said.
They may take on the traits of the people who they’re surrounded by or continually look to those people for validation. But deep down, they may feel empty.
How is B.P.D. treated?
Antidepressants and other medications can address B.P.D. symptoms, but only therapy will get to the root of the problem, the experts said. Many patients benefit from a “life renovation,” not only to help them get back on track but also to “change their concept of themselves and their relationship to other people,” Dr. Choi-Kain said.
In the United States, the most common modality to treat B.P.D. is dialectical behavior therapy or D.B.T., which focuses on helping people develop mindfulness and practical skills to manage their emotions.
Other evidence-based methods of treating B.P.D. include mentalization-based treatment, a type of therapy that aims to help people reflect realistically about what goes on in the minds of themselves or others during social interactions; and transference-focused psychotherapy, which uses the relationship dynamic between the therapist and client to explore how the client perceives others.
Humans are creatures of Earth and, in turn, at the mercy of Earth’s gravity. When we leave the confines of our home planet and enter the microgravity environment of space, our brain and body change. Studies have shown how microgravity can affect astronauts: it can throw off their balance, blur their vision, change the shape of their heart, and nudge the position of their brain inside their skull. And now a new study shows that microgravity, colloquially referred to as zero g, affects astronauts’ motor skills, too. Understanding these changes is critical for the future of human space exploration.
“It’s so important to interact with our environment,” says Philippe Lefèvre, senior author of the new study and a professor of biomedical engineering at the Catholic University of Louvain in Belgium. Unlike on Earth, in space, if an astronaut lets an object slip from their grasp, the consequences are not just different (that object doesn’t drop to the floor) but also possibly dire.
“This study highlights the brain’s remarkable ability to adapt to its physical environment,” says Lionel Bringoux, a professor at Aix-Marseille University in France, who also researches the effects of gravity on motor ability but was not involved in the new paper.
The new research involved 11 astronauts who lived onboard the International Space Station for at least five months. While on the station, they performed a series of experiments that tested how their rhythm and grip changed while they manipulated objects in zero g. Lefèvre and his colleagues found that astronauts tended to move slower in weightlessness and to grip an object more firmly than they would on Earth, as if the object was heavier than they knew it to be.
That was a surprise, Lefèvre says: “The fact that we were exposed to gravity from early childhood for years and decades, we cannot forget it, even after five to six months.” The astronauts knew that the object would feel weightless in zero g, but their brain predicted that it would feel as heavy as it would on Earth. And if the object was moving at speed, the astronauts would grab it and grip it even more tightly, he adds.
Bringoux says that this finding suggests “astronauts tend to apply a larger safety margin” than is strictly necessary for holding on to and moving objects to prevent any unexpected slips. It also suggests that astronauts reach an “optimal” level of adaptation to their weightless surroundings—their sensorimotor skills change enough to ensure they can safely and accurately hold on to and move things around in microgravity but not more than that.
The team ran further experiments to see how the astronauts’ motor skills readapted to the planet’s gravitational force just a day after they returned to Earth—both their grip and ability to move an object at a steady rhythm recovered quickly. “The adaptation that we had to gravity for decades [means] we do not fully adapt to microgravity, but the advantage is that when we go back to Earth, we readapt that very quickly to the Earth’s environment,” Lefèvre says. All in all, the study, which was published on Monday in the Journal of Neuroscience, took about 20 years from when it was first proposed to be completed.
Knowing how human brains adapt to different gravitational environments will be crucial for future space missions—although it’s an open question whether future astronauts traveling to the moon or Mars will show the same adaptations, Lefèvre says. There is some gravity on these worlds, and that could introduce risks, he adds. “Maybe the astronaut will feel gravity, and they will just go back to Earth mode, which is not appropriate because gravitational force [on Mars] is reduced,” he says.
“Studying these differences helps us anticipate and better prepare astronauts for such conditions,” Bringoux agrees.
This week’s Star Gazing roundup features appearances across film, fashion, and culture, with artists and actors showing up for major moments and smaller gatherings alike. From red carpets to private events, the past few days reflect how active the calendar has been, with familiar faces stepping out in cities across the country.
In San Diego, Swizz Beatz and Alicia Keys brought their Dean Collection to the Museum of Contemporary Art for its West Coast debut, drawing out Kelly Rowland and Tim Witherspoon for the opening night celebration. Just up the coast in Los Angeles, the AFI honored Eddie Murphy with its Lifetime Achievement Award, bringing together Colman Domingo, Nia Long, Jaafar Jackson, Tracy Morgan, Spike Lee, Da’Vine Joy Randolph, and more for a night centered on his legacy.
In Los Angeles, Tina Knowles hosted a luncheon tied to a Mother’s Day campaign with Kurt Geiger London, joined by Vanessa Bell Calloway, Holly Robinson Peete, Lela Rochon, and Vivica A. Fox. Las Vegas stayed busy with CinemaCon, where Michael B. Jordan previewed his next project, Queen Latifah received the Cultural Impact in Film Award, and LaKeith Stanfield took the stage as one of the night’s honorees. Dwayne Johnson also made an appearance during studio presentations, keeping attention on upcoming releases.
Take a look at who was seen out and about this week.
Swizz Beatz, Alicia Keys, Kelly Rowland, and Tim Witherspoon
LA JOLLA, CALIFORNIA – APRIL 17: (L-R) Swizz Beatz, Alicia Keys, Kelly Rowland, and Tim Witherspoon attend the opening of the west coast showing of Giants- Art from The Dean Collection of Swizz Beatz and Alicia Keys at Museum Of Contemporary Art San Diego on April 17, 2026, in La Jolla, California. (Photo by Jerod Harris/Getty Images for ABA)
Karen Pittman arrives at 51st AFI Lifetime Achievement Award ceremony.
LOS ANGELES, CALIFORNIA – APRIL 18: Karen Pittman arrives at 51st AFI Lifetime Achievement Award: A Tribute Celebrating Eddie Murphy at Dolby Theatre on April 18, 2026, in Los Angeles, California. (Photo by Leon Bennett/Getty Images)
Spike Lee and Martin Lawrence
LOS ANGELES, CALIFORNIA – APRIL 18: (L-R) Spike Lee and Martin Lawrence arrive at 51st AFI Lifetime Achievement Award: A Tribute Celebrating Eddie Murphy at Dolby Theatre on April 18, 2026, in Los Angeles, California. (Photo by Leon Bennett/Getty Images)
Martin Lawrence, Eddie Murphy, and Tracy Morgan
HOLLYWOOD, CALIFORNIA – APRIL 18: (L-R) Martin Lawrence, Eddie Murphy, and Tracy Morgan attend the 51st AFI Life Achievement Award: A Tribute To Eddie Murphy at Dolby Theatre on April 18, 2026, in Hollywood, California. (Photo by Michael Kovac/Getty
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LAS VEGAS, NEVADA – APRIL 15: Michael B. Jordan speaks during CinemaCon 2026 – Amazon MGM Studios Invites you to an Exclusive Presentation of its Upcoming Slate at The Dolby Colosseum at Caesars Palace during CinemaCon, the official convention of Cinema United, on April 15, 2026, in Las Vegas, Nevada. (Photo by David Becker/Getty Images for CinemaCon)
Democrats maintained their electoral momentum on Tuesday by securing the passage of an aggressively gerrymandered House map in Virginia, which could deliver the party up to four extra seats as it tries to win back control of Congress.
National party leaders had been heavily invested in the outcome, with Representative Hakeem Jeffries of New York, the minority leader, helping orchestrate the statewide Virginia referendum with Democratic state legislators. Speaker Mike Johnson, hanging on to a slim majority, tried to rally the state’s Republicans.
Democrats sought to focus the campaign on President Trump, who instigated the nationwide redistricting fight last summer in Texas to help House Republicans in the midterms. A vote for a gerrymandered House map, Democrats argued, was a vote to help their party stop Mr. Trump’s agenda. The president stayed out of the contest until the final hours before Election Day, when he urged Virginians to block the map.
“Donald Trump tried to rig the midterm elections by gerrymandering the national congressional map,” Mr. Jeffries said in an interview on Tuesday night. “He has failed.”
Here are four takeaways from the election:
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Democrats have fought to a draw in the clash over maps — for now.
The vote in Virginia erased the small structural advantage that Republicans had built in the country’s redistricting battle.
Republicans could still seize back their edge, however, with the prospect of a new map in Florida. And the Supreme Court may well set off a political earthquake with a ruling that upends a key provision of the Voting Rights Act, which could lead to more Republican gains.
But for now, Democrats have averted their fears from the start of the gerrymandering fight that Republicans could gain an overwhelming cartographic advantage. And with the political environment shifting in their favor, they are increasingly optimistic about winning back the House.
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National party leaders were heavily invested in Virginia’s referendum, and tens of millions of dollars flowed in. Credit…Win McNamee/Getty Images
President Donald Trump’s recent executive order to accelerate research on psychedelic substances and their potential to treat mental health conditions could have wide-ranging science consequences. Experts say the directive could expedite studies on how psychedelic and hallucinatory drugs such as MDMA, psilocybin, LSD and ibogaine may be useful in medicine.
The executive order is “timely,” says Frederick Barrett, director of the Center for Psychedelic and Consciousness Research at Johns Hopkins University. “If this executive order can help us to really push forward promising therapies more quickly, then I think that is a good thing,” he says.
The order directs the administration to promptly evaluate and possibly approve psychedelics for medical purposes, which could also make it easier for researchers to study these substances. It also calls for allocating $50 million to support states’ psychedelic research, including on ibogaine, a compound found naturally in a Central African plant. Some early research suggests that ibogaine could help treat depression and substance use disorders in some people, but it has been shown to have serious side effects.
An estimated 15.4 million adults in the U.S. live with severe mental illness, according to the National Institutes of Health. Veterans are at particular risk: Research shows that suicide rates are nearly twice as high among veterans as they are in the general population. And existing drugs, such as selective serotonin reuptake inhibitors (SSRIs), that are designed to treat depression and other mental health conditions, aren’t always effective or accessible for everyone. An increasingly vocal cadre of researchers believe psychedelic substances could offer more effective treatments. And in some clinical trials, psilocybin, MDMA, and LSD have been found to have promising results in treating mental health conditions.
“We need better treatments,” says Alan Davis, director of the Center for Psychedelic Drug Research and Education at the Ohio State University. “We need to be able to help people, and I think psychedelic therapies will offer a new way in which to do that.”
But research into these drugs is slow and hard to do, not least because the U.S. government categorizes many psychedelics as Schedule I drugs, which means they are considered to be dangerous and to have a high potential for abuse and “no currently accepted medical use,” according to the definition in the Code of Federal Regulations. In most cases, the possession of such drugs is federally criminalized, and that adds significant hurdles for researchers who are trying to study their effects.
That’s part of the reason why very few therapies that use psychedelic drugs have been approved for use in the U.S. One of the most well studied psychedelics, MDMA, was set back in 2024 when, citing insufficient and flawed research, the Food and Drug Administration rejected a proposal to approve it as a treatment for post-traumatic stress disorder.
An FDA approval for one of these drugs would make further research “much less difficult” for scientists, Davis says. “You would change the requirements involved, which means we could do a lot more research for a lot less money on those treatments.”
He hopes that the executive order signals a change in the government’s approach. “It is really quite remarkable that a sitting president has made this statement as part of official executive orders,” Davis says.
“That act, in and of itself, is, I think, going to really escalate the research in this space,” he adds, “and hopefully make these treatments available to people that need them as quickly as possible.”
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Psilocybe mushrooms at a lab in British Columbia in 2021. James MacDonald/Bloomberg/Getty Images
Film and Writing Festival for Comedy. Showcasing best of comedy short films at the FEEDBACK Film Festival. Plus, showcasing best of comedy novels, short stories, poems, screenplays (TV, short, feature) at the festival performed by professional actors.
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Vanessa Saba
NASA
LAS VEGAS, NEVADA – APRIL 15: Michael B. Jordan speaks during CinemaCon 2026 – Amazon MGM Studios Invites you to an Exclusive Presentation of its Upcoming Slate at The Dolby Colosseum at Caesars Palace during CinemaCon, the official convention of Cinema United, on April 15, 2026, in Las Vegas, Nevada. (Photo by David Becker/Getty Images for CinemaCon)
National party leaders were heavily invested in Virginia’s referendum, and tens of millions of dollars flowed in. Credit…Win McNamee/Getty Images
James' World 2 