Super-Agers - Tadpole Parenting - Evolving Neurotoxins - Timothy Disease

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Apr 30, 2024, 8:23:19 AMApr 30

https://www.nytimes.com/2024/04/29/well/mind/super-agers-study.html

A Peek Inside the Brains of ‘Super-Agers’

By Dana G. Smith

When it comes to aging, we tend to assume that cognition gets worse as we get older. Our thoughts may slow down or become confused, or we may start to forget things, like the name of our high school English teacher or what we meant to buy at the grocery store.

But that’s not the case for everyone.

For a little over a decade, scientists have been studying a subset of people they call “super-agers.” These individuals are age 80 and up, but they have the memory ability of a person 20 to 30 years younger.

Most research on aging and memory focuses on the other side of the equation — people who develop dementia in their later years. But, “if we’re constantly talking about what’s going wrong in aging, it’s not capturing the full spectrum of what’s happening in the older adult population,” said Emily Rogalski, a professor of neurology at the University of Chicago, who published one of the first studies on super-agers in 2012.

A paper published Monday in the Journal of Neuroscience helps shed light on what’s so special about the brains of super-agers. The biggest takeaway, in combination with a companion study that came out last year on the same group of individuals, is that their brains have less atrophy than their peers’ do.

The research was conducted on 119 octogenarians from Spain: 64 super-agers and 55 older adults with normal memory abilities for their age. The participants completed multiple tests assessing their memory, motor and verbal skills; underwent brain scans and blood draws; and answered questions about their lifestyle and behaviors.

The scientists found that the super-agers had more volume in areas of the brain important for memory, most notably the hippocampus and entorhinal cortex. They also had better preserved connectivity between regions in the front of the brain that are involved in cognition. Both the super-agers and the control group showed minimal signs of Alzheimer’s disease in their brains.

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https://knowablemagazine.org/content/article/living-world/2024/the-amphibians-that-evolved-parental-care

The tender art of tadpole parenting

By Tim Vernimmen

Most amphibians aren’t exactly doting parents — they just find a partner and release as many eggs or sperm as possible, in hopes that viable larvae will hatch from at least some fertilized eggs, and at least some of those larvae will survive to adulthood.

Yet in as many as one in five amphibian species, one or both parents stick around to care for their offspring, using a staggering variety of strategies.

The most well-known amphibian parents are the brightly colored poison frogs, a group of around 200 species that will repeatedly be leaping into view in this article. Yet their parenting skills may not be as exceptional as once thought, says biologist Jennifer Stynoski of the University of Costa Rica, who decided to study this group when she spotted them on a field trip as a student years ago. “I think they’ve just received a lot of attention because they’re so beautiful. They’re very cute to study.”

So — what makes an exemplary amphibian parent? Much remains to be discovered, but some common principles have emerged.
Stay away from the water

Unlike reptiles and the birds that evolved from them, the ancestors of today’s amphibians never developed eggs with tough, watertight shells. This means their eggs need water to survive, as do the gilled larvae that usually come wriggling out.

Yet the ponds in which many amphibians deposit their eggs are full of other animals, many eager to supplement their diet by slurping up a mouthful of eggs. “This must be one reason why so many species have evolved ways to lay their eggs away from the water,” says behavioral ecologist Eva Ringler of the University of Bern in Switzerland.

https://nautil.us/the-animals-that-turn-bodily-fluids-into-weapons-564464/?_sp=2cf1f786-fbc5-4634-b698-48a6c0c04a09.1714478730355

The Animals That Turn Bodily Fluids into Weapons

By Kristen French

Combat in nature is often a matter of tooth and claw, fang and talon. But some creatures have devised devious and dramatic ways to weaponize their bodily fluids, expelling them in powerful streams for the purposes of attack or self-defense.

Researcher Elio Challita became fascinated by fluid ejections in nature when he began studying an insect called the sharpshooter, which pees one droplet at a time using a method called superpropulsion. These insects consume 300 times their own body weight per day in xylem sap, a watery solution of minerals and other nutrients found in the roots, stems, and leaves of plants. To efficiently expel the resulting waste, they use a kind of internal catapult that helps overcome the surface tension in the droplets.

Challita and a team of researchers from the Bhamla Lab at Georgia Tech decided to survey the biomechanics and fluid dynamics that govern fluid ejections across the animal kingdom to see what commonalities they could find. Among others, they identified a number of creatures that use bodily fluids as powerful weapons in the fight for survival. These fluid ejections defy gravity and rebel against traditional notions of predator-prey tactics.

The team’s review, “Fluid Ejections in Nature,” is forthcoming in the Annual Review of Chemical and Biological Engineering.

1. Ringnecked Spitting Cobra

Cobras of the Naja genus defend against threats by spitting venom with extreme precision toward the eyes of an enemy, up to 6.5 feet away. These snakes release the venom through hollow microscopic fangs and can adjust the distribution of their spit with rapid movements. Spitting cobras have a venom discharge orifice that is more circular in shape than non-spitting species, which gives the venom more forward force. Contraction in the venom gland also helps. A 90-degree bend near the lip of the orifice gives the snake more precise control over venom flow. Naja pallida cobras can spit venom at average speeds of 1.27 milliliters per second.

https://www.npr.org/sections/health-shots/2024/04/30/1247900797/timothy-syndrome-genetic-disorder-brain-cells-restored

Scientists restore brain cells impaired by a rare genetic disorder

Jon Hamilton

Scientists have found a way to restore brain cells impaired by a rare and life-threatening genetic disorder called Timothy syndrome.

A type of drug known as an antisense oligonucleotide allowed clusters of human neurons to develop normally even though they carried the mutation responsible for Timothy syndrome, a team reports in the journal Nature.

The approach may help researchers develop treatments for other genetic conditions, including some that cause schizophrenia, epilepsy, ADHD, and autism spectrum disorder.

"It's immensely exciting because we now have the tools," says Dr. Sergiu Pasca, a professor of psychiatry and behavioral sciences at Stanford University and the study's senior author.

"It's the beginning of a new era for many of these diseases that we first thought were untreatable," says Dr. Huda Zoghbi, a professor at Baylor College of Medicine who was not involved in the research.

But most of these conditions involve multiple genes, not just one — and scientists don't yet know enough about these multiple gene disorders to effectively treat them with antisense oligonucleotides, Zoghbi says.

Timothy Syndrome has been diagnosed in fewer than 100 people worldwide. Children born with it often have heart problems, autism, epilepsy, developmental delay, and intellectual disability.

But because Timothy syndrome is caused by a mutation in a single gene, it offers scientists a way to study changes that affect brain development.

"Rare syndromes that are very clearly defined genetically are sort of like windows, or Rosetta Stones, into understanding other, more common conditions," Pasca says.

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https://nautil.us/how-whales-could-help-us-speak-to-aliens-559443/?_sp=2cf1f786-fbc5-4634-b698-48a6c0c04a09.1714478720492

How Whales Could Help Us Speak to Aliens

By Claire Cameron

On Aug. 19, 2021, a humpback whale named Twain whupped back. Specifically, Twain made a series of humpback whale calls known as “whups” in response to playback recordings of whups from a boat of researchers off the coast of Alaska. The whale and the playback exchanged calls 36 times.

On the boat was naturalist Fred Sharpe of the Alaska Whale Foundation, who has been studying humpbacks for over two decades, and animal behavior researcher Brenda McCowan, a professor at the University of California, Davis. The exchange was groundbreaking, Sharpe says, because it brought two linguistic beings—humans and humpback whales—together. “You start getting the sense that there’s this mutual sense of being heard.”

In their 2023 published results, McGowan, Sharpe, and their coauthors are careful not to characterize their exchange with Twain as a conversation. They write, “Twain was actively engaged in a type of vocal coordination” with the playback recordings. To the paper’s authors, the interspecies exchange could be a model for perhaps something even more remarkable: an exchange with an extraterrestrial intelligence.

Sharpe and McGowan are members of Whale SETI, a team of scientists at the SETI Institute, which has been scanning the skies for decades, listening for signals that may be indicative of extraterrestrial life. The Whale SETI team seeks to show that animal communication, and particularly, complex animal vocalizations like those of humpback whales, can provide scientists with a model to help detect and decipher a message from an extraterrestrial intelligence. And, while they’ve been trying to communicate with whales for years, this latest reported encounter was the first time the whales talked back.

It all might sound far-fetched. But then again, Laurance Doyle, an astrophysicist who founded the Whale SETI team and has been part of the SETI Institute since 1987, is accustomed to being doubted by the mainstream science community.

https://www.nytimes.com/2024/04/25/well/mind/antidepressants-side-effects-anxiety-stress.html

What You Really Need to Know About Antidepressants

By Christina Caron

Antidepressants are among the most prescribed medications in the United States. This is, in part, because the number of people diagnosed with depression and anxiety has been on the rise, and prescriptions jumped sharply among some age groups during the pandemic.

Despite the prevalence of these medications, some patients have “significant misconceptions” about how the drugs work, said Dr. Andrew J. Gerber, a psychiatrist and the president and medical director of Silver Hill Hospital in New Canaan, Conn.

About 80 percent of antidepressants are prescribed by primary care doctors who have not had extensive training in managing mental illness.

Dr. Paul Nestadt, an associate professor of psychiatry at the Johns Hopkins School of Medicine, said patients tell him, “‘You know, Doc, I’ve tried everything.’” But often, he said, “they never got to a good dose, or they were only on it for a week or two.”

Here are some answers to frequently asked questions about antidepressants.
How do antidepressants work?

There are many types of antidepressants, and they all work a bit differently.

In general, they initiate a change in the way brain cells — and different regions of the brain — communicate with one another, said Dr. Gerard Sanacora, a professor of psychiatry at the Yale School of Medicine.

Clinical trials have shown that antidepressants are generally more effective with moderate, severe and chronic depression than with mild depression. Even then, it’s a modest effect when compared with placebo.