Urination Signals - Misinformed Tongue - Inside-Out Alzheimer's - Metallic Woodpeckers

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Jun 2, 2024, 7:25:16 AMJun 2

https://knowablemagazine.org/content/article/health-disease/2024/how-do-we-sense-the-need-to-urinate

To pee or not to pee? That is a question for the bladder — and the brain

By Emily Underwood

You’re driving somewhere, eyes on the road, when you start to feel a tingling sensation in your lower abdomen. That extra-large Coke you drank an hour ago has made its way through your kidneys into your bladder. “Time to pull over,” you think, scanning for an exit ramp.

To most people, pulling into a highway rest stop is a profoundly mundane experience. But not to neuroscientist Rita Valentino, who has studied how the brain senses, interprets and acts on the bladder’s signals. She’s fascinated by the brain’s ability to take in sensations from the bladder, combine them with signals from outside of the body, like the sights and sounds of the road, then use that information to act — in this scenario, to find a safe, socially appropriate place to pee. “To me, it’s really an example of one of the beautiful things that the brain does,” she says.

Scientists used to think that our bladders were ruled by a relatively straightforward reflex — an “on-off” switch between storing urine and letting it go. “Now we realize it’s much more complex than that,” says Valentino, now director of the division of neuroscience and behavior at the National Institute of Drug Abuse. An intricate network of brain regions that contribute to functions like decision-making, social interactions and awareness of our body’s internal state, also called interoception, participates in making the call.

In addition to being mind-bogglingly complex, the system is also delicate. Scientists estimate, for example, that more than 1 in 10 adults have overactive bladder syndrome — a common constellation of symptoms that includes urinary urgency (the sensation of needing to pee even when the bladder isn’t full), nocturia (the need for frequent nightly bathroom visits) and incontinence. Although existing treatments can improve symptoms for some, they don’t work for many people, says Martin Michel, a pharmacologist at Johannes Gutenberg University in Mainz, Germany, who researches therapies for bladder disorders. Developing better drugs has proven so challenging that all major pharmaceutical companies have abandoned the effort, he adds.

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https://www.nytimes.com/2024/05/29/science/taste-buds-tongue-map.html

The Textbooks Were Wrong About How Your Tongue Works

[Ahem some textbooks—Ed. Note]

By Joanne Silberner

Think for a minute about the little bumps on your tongue. You probably saw a diagram of those taste bud arrangements once in a biology textbook — sweet sensors at the tip, salty on either side, sour behind them, bitter in the back.

But the idea that specific tastes are confined to certain areas of the tongue is a myth that “persists in the collective consciousness despite decades of research debunking it,” according to a review published this month in The New England Journal of Medicine. Also wrong: the notion that taste is limited to the mouth.

The old diagram, which has been used in many textbooks over the years, originated in a study published by David Hanig, a German scientist, in 1901. But the scientist was not suggesting that various tastes are segregated on the tongue. He was actually measuring the sensitivity of different areas, said Paul Breslin, a researcher at Monell Chemical Senses Center in Philadelphia. “What he found was that you could detect things at a lower concentration in one part relative to another,” Dr. Breslin said. The tip of the tongue, for example, is dense with sweet sensors but contains the others as well.

The map’s mistakes are easy to confirm. If you place a lemon wedge at the tip of your tongue, it will taste sour, and if you put a bit of honey toward the side, it will be sweet.

The perception of taste is a remarkably complex process, starting from that first encounter with the tongue. Taste cells have a variety of sensors that signal the brain when they encounter nutrients or toxins. For some tastes, tiny pores in cell membranes let taste chemicals in.

Such taste receptors aren’t limited to the tongue; they are also found in the gastrointestinal tract, liver, pancreas, fat cells, brain, muscle cells, thyroid and lungs. We don’t generally think of these organs as tasting anything, but they use the receptors to pick up the presence of various molecules and metabolize them, said Diego Bohórquez, a self-described gut-brain neuroscientist at Duke University. For example, when the gut notices sugar in food, it tells the brain to alert other organs to get ready for digestion.

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https://www.thetransmitter.org/alzheimers-disease/reviving-inside-out-hypothesis-of-amyloid-beta-to-explain-alzheimers-mysteries/

Reviving ‘inside-out’ hypothesis of amyloid beta to explain Alzheimer’s mysteries

By Elissa Welle

The traditional story of Alzheimer’s disease casts two key proteins in starring roles—each with clear stage directions: Plaques of sticky amyloid beta protein accumulate outside neurons as the condition unfolds, and tangles of tau protein gum up the insides of the cells.

But it may be time for a rewrite. Amyloid beta, too, coalesces inside neurons and seems to mark them for early death, according to research posted on a preprint server last November. In brain slices from people with Alzheimer’s, but not in those from age-matched controls, cells containing intracellular amyloid beta decreased in number as the disease progressed.

At first, the result appeared to be a mistake, says study investigator Alessia Caramello, a postdoctoral researcher in the UK Dementia Research Institute. Intracellular amyloid beta is “nowhere to be found” in most discussions of Alzheimer’s disease, she says. “It’s never mentioned. Never ever.” Instead, the field has long focused on the buildup of amyloid beta outside the cell.

But even before those plaques form, there seems to be another pathological event, she says—namely intracellular amyloid—“Why not look at it?”

The work from Caramello and her colleagues is not the first to suggest that amyloid beta, or Abeta for short, wreaks havoc inside neurons, not just in the extracellular space between them. This “inside-out” hypothesis, as it has been called, has implications for how scientists understand Alzheimer’s disease. In particular, it could help to account for some big mysteries around the condition—such as why the extent of amyloid beta plaques in the brain doesn’t always correlate with symptoms, why neurons die and why treatments to lessen plaques marginally slow down, but do not halt, the disease.

“It just puts a totally different spin on how you need to address this,” says Gunnar Gouras, professor of experimental neurology at Lund University and a proponent of the inside-out hypothesis. “It’s really a cell biological, neurobiological issue that is a bit more complex. And we need to also study this instead of just saying, ‘Abeta is bad; we’ve got to get rid of it.’”

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https://www.nytimes.com/2024/05/31/business/economy/alzheimers-disease-personal-finance.html

Alzheimer’s Takes a Financial Toll Long Before Diagnosis

By Ben Casselman

Long before people develop dementia, they often begin falling behind on mortgage payments, credit card bills and other financial obligations, new research shows.

A team of economists and medical experts at the Federal Reserve Bank of New York and Georgetown University combined Medicare records with data from Equifax, the credit bureau, to study how people’s borrowing behavior changed in the years before and after a diagnosis of Alzheimer’s or a similar disorder.

What they found was striking: Credit scores among people who later develop dementia begin falling sharply long before their disease is formally identified. A year before diagnosis, these people were 17.2 percent more likely to be delinquent on their mortgage payments than before the onset of the disease, and 34.3 percent more likely to be delinquent on their credit card bills. The issues start even earlier: The study finds evidence of people falling behind on their debts five years before diagnosis.

“The results are striking in both their clarity and their consistency,” said Carole Roan Gresenz, a Georgetown University economist who was one of the study’s authors. Credit scores and delinquencies, she said, “consistently worsen over time as diagnosis approaches, and so it literally mirrors the changes in cognitive decline that we’re observing.”

The research adds to a growing body of work documenting what many Alzheimer’s patients and their families already know: Decision-making, including on financial matters, can begin to deteriorate long before a diagnosis is made or even suspected. People who are starting to experience cognitive decline may miss payments, make impulsive purchases or put money into risky investments they would not have considered before the disease.

“There’s not just getting forgetful, but our risk tolerance changes,” said Lauren Hersch Nicholas, a professor at the University of Colorado School of Medicine who has studied dementia’s impact on people’s finances. “It might seem suddenly like a good move to move a diversified financial portfolio into some stock that someone recommended.”

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https://www.npr.org/2024/05/31/g-s1-1606/woodpeckers-bang-metal-homes-loud-urban-noise-mating

'Chimney caps, vent pipes, gutters': Why some woodpeckers are major metal heads

Sacha Pfeiffer

A few weeks ago, at about 6:45 in the morning, I was at home, waiting to talk live on the air with Morning Edition host Michel Martin about a story I'd done, when I suddenly heard a loud metallic hammering. It sounded like a machine was vibrating my house.

It happened again about 15 seconds later. And again after that.

This rhythmic clatter seemed to be coming from my basement utility closet. Was my furnace breaking? Or my water heater? I worried that it might happen while I was on the air.

Luckily, the noise stopped while I spoke with Michel, but restarted later. This time I heard another sound, a warbling or trilling, possibly inside my chimney.

Was there an animal in there? I ran outside, looked up at my roof — and saw a woodpecker drilling away at my metal chimney cap.

I've seen and heard plenty of woodpeckers hammer on trees. But never on metal. So to find out why the bird was doing this, I called an expert: Kevin McGowan, an ornithologist at the Cornell Lab of Ornithology who recently created a course called "The Wonderful World of Woodpeckers."

McGowan said woodpeckers batter wood to find food, make a home, mark territory and attract a mate. But when they bash away at metal, "what the birds are trying to do is make as big a noise as possible," he said, "and a number of these guys have found that — you know what? If you hammer on metal, it's really loud!"

Woodpeckers primarily do this during the springtime breeding season, and their metallic racket has two purposes, "basically summarized as: All other guys stay away, all the girls come to me," McGowan said. "And the bigger the noise, the better."

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https://www.nytimes.com/2024/05/31/health/mdma-fda-ptsd-treatment.html

F.D.A.’s Review of MDMA Cites Health Risks and Study Flaws

By Andrew Jacobs and Christina Jewett

The Food and Drug Administration on Friday raised concerns about the health effects of MDMA as a treatment for post-traumatic stress disorder, citing flaws in a company’s studies that could pose major obstacles to approval of a treatment anticipated to help people struggling with the condition.

The agency said that bias had seeped into the studies because participants and therapists were readily able to figure out who got MDMA versus a placebo. It also flagged “significant increases” in blood pressure and pulse rates that could “trigger cardiovascular events.”

The staff analysis was conducted for an independent advisory panel that will meet Tuesday to consider an application by Lykos Therapeutics for the use of MDMA-assisted therapy. The agency’s concerns highlight the unique and complex issues facing regulators as they weigh the therapeutic value of an illegal drug commonly known as Ecstasy that has long been associated with all-night raves and cuddle puddles.

Approval would mark a seismic change in the nation’s tortuous relationship with psychedelic compounds, most of which the Drug Enforcement Administration classifies as illegal substances that have “no currently accepted medical use and a high potential for abuse.”

Research like the current studies on MDMA therapy have corralled the support of various groups and lawmakers from both parties for treatment of PTSD, a condition affecting millions of Americans, especially military veterans who face an outsize risk of suicide. No new therapy has been approved for PTSD in more than 20 years.

“What’s happening is truly a paradigm shift for psychiatry,” said David Olson, director of the U.C. Davis Institute for Psychedelics and Neurotherapeutics. “MDMA is an important step for the field because we really lack effective treatments, period, and people need help now.”