Musings: 2026 (current posts)

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Musings: 2026 (current posts)

Musings is an informal newsletter mainly highlighting recent science. It is intended as both fun and instructive. See the Introduction, listed below and in the navigation bar at the top, for more information.

In mid-2023, Musings transitioned to a new format, for a semi-retirement phase. With some adjustments, it is now similar to the earlier "briefly noted" format. The format is flexible, and contributions can be in various formats by agreement.

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Current posts -- 2026
   New items
   January

Older items are on the archive pages, listed below.

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New items

Can a person get both cancer and Alzheimer's disease?

February 18, 2026

An odd question! Why did it even come up?

Actually, there have long been reports suggesting that cancer patients have a reduced incidence of Alzheimer's disease (AD).

A new article provides evidence for how this might work. It's an interesting -- and complex -- finding. But it could offer a path to a drug against AD.

The authors of the current article use the term 'peripheral cancer'. That is, there is a brain effect of a cancer at a distant site. (I don't know if brain cancer was included in any of the background work reporting a connection.)

Most of the work here is with mice. At least some points that were checked seem to hold also for humans.

A simple version of the story is that mice with tumors show reduced levels of the amyloid plaque that is so characteristic of AD.

Testing of secretions from the tumors led to identifying a particular protein responsible for the effect. That protein is called cystatin-c (Cyst-C). Tumor-free mice injected with Cyst-C show loss of amyloid plaque -- and improvement on a mental test. Obviously, identifying a specific protein as central to the effect is a key point.

What does Cyst-C do? It clearly travels to the brain, via the bloodstream. There, two effects have been shown. One, it activates the microglia to attack amyloid plaque; sounds useful. Two, it binds to amyloid plaque. It may be that these two effects work together to deliver plaque protein to the microglia.

Back to the title question... Indeed there is an unexpected connection. The current article begins to explore how that connection works -- how having cancer could reduce AD. Fascinating -- and maybe even a lead for drug development.

* News story: Cancer tumors may protect against Alzheimer's by cleaning out protein clumps. (Paul Arnold, Medical Xpress, January 24, 2026.)
* The article: Peripheral cancer attenuates amyloid pathology in Alzheimer's disease via cystatin-c activation of TREM2. (Xinyan Li et al, Cell 189:853, February 5, 2026.) (The pdf file, including supplemental material is 51 pages.) If you get the pdf, I encourage you to read the authors' Limitations section, p 16.

More microglia: Anxiety. 2. An immune system connection (February 4, 2026). Also notes a post about a connection of AD and microglia.

This post is listed on my page for Biotechnology in the News (BITN) -- Other topics under both Alzheimer's disease and Cancer.

Do earthquakes enhance algal blooms?

February 11, 2026

One way to think about the title question might be... Sure, why not? Earthquakes shake things up. They may shake up the sea floor, leading to an upwelling of nutrients. Or the quakes may crack the sea floor, allowing release of nutrients from below.

The better question might be... Is there any evidence on the matter? And the answer to that is that a new article reports that phytoplankton blooms in one well-studied part of the ocean are larger when there has been a recent earthquake in the area.

The scene is the Southern Ocean, near Antarctica. Scientists have long observed that the algal blooms that appear each summer vary widely in size from one year to the next. Recently, the size of the algal blooms was connected to varying levels of a key nutrient: iron.

The new finning is that summers with large algal blooms were preceded (by a few months) by significant earthquakes under the ocean floor. The scientists suggest that the quakes cause deep sea vents to release iron, which -- surprisingly rapidly -- makes its way to the surface waters. The story is incomplete at this point, but a fair amount of data seems consistent with it.

I use the terms algal bloom and phytoplankton bloom interchangeably, for simplicity. What was actually measured was "net primary production", a measure of photosynthesis. That photosynthesis was due largely to tiny organisms -- commonly called phytoplankton, and consisting largely of algae

A possible big-picture implication... Larger algal blooms mean there is more photosynthesis -- and hence more removal of CO₂ from the air. That leads to the possibility that earthquakes could significantly affect the level of atmospheric CO₂ -- and hence climate. More information on the global distribution of the effect would be needed to evaluate the importance of this idea.

* News stories:
- The Strange Link Between Winter Earthquakes and Massive Summer Algae Blooms The Size of California -- Seafloor tremors appear to shape summer plankton blooms and carbon uptake. (Tudor Tarita, ZME Science, January 15, 2026.)
- Deep ocean earthquakes drive Southern Ocean's massive phytoplankton blooms, study finds. (Adam Hadhazy, Doerr School of Sustainability, Stanford University, December 17, 2025.)
* The article: Southern Ocean net primary production influenced by seismically modulated hydrothermal iron. (Casey M S Schine et al, Nature Geoscience 19:106, January 2026.)

Meteorites and algal blooms... A major algal bloom associated with the dinosaur extinction event? (May 13, 2016).

Among many posts about earthquakes... Earthquakes induced by human activity: oil drilling in Los Angeles (February 12, 2019). Links to more.

Anxiety. 2. An immune system connection

February 4, 2026

We now look at our second anxiety article, which finds a connection between certain cell types in the brain and anxiety disorders. (The previous post, just below, found a correlation between the level of the chemical choline in the brain and anxiety disorders.)

It's a complicated article. The two cell types are two types of microglia. These are immune system cells involved in cleaning up neurons. The big idea here is that these two types of microglia have opposite effects on anxiety responses. One type enhances the anxiety response, the other type reduces it. One might refer to them as accelerator and brake; in fat, those are the terms used by the authors.

To study this, the scientists needed to be able to manipulate the levels of these cell types. For example, in one set of experiments, they first made mutant mice lacking microglia. They could them add back one or another type of microglia, as desired for each experiment. The big picture result is that the two types of microglia had those opposite effects.

At this point, there is no understanding of how these effects occur. Nevertheless, the work suggests an important role for cells of the immune system in what we would usually call a psychiatric disorder. That in itself makes the work intriguing.

General comment on the pair of posts about anxiety...

Both posts offer some clue about what is going on. But both are small steps, and need follow-up.

The previous post focused on a nutrient (choline). That could lead to a trial to see if feeding the nutrient as a supplement affects anxiety. But we must remember that the reported effect is, for now, just a correlation. We really don't know why this is happening, and thus do not know that manipulating the choline level would have any effect.

The current post looks at the cell level. It may be a step in understanding how anxiety is modulated. But for now, it is not obvious what to do about it, except to study it more.

* News stories. The article here is complicated; both news stories here do reasonable job of guiding you through the basics. Still, don't be surprised if you get a bit overwhelmed at times.
- Scientists Discover Brain Immune Cells That Control Anxiety and Compulsive Behavior -- The study, which was carried out on mice, is a paradigm shift. (Mihai Andrei. ZME Science, November 17, 2025.) Delightful use of metaphor, along with a good overview of the work itself.
- Researchers find the "gas pedal" and "brake" for anxiety, and they aren't neurons. (Karina Petrova, PsyPost, November 18, 2025.)
* The article (open access): Defective Hoxb8 microglia are causative for both chronic anxiety and pathological overgrooming in mice. (Donn A Van Deren et al, Molecular Psychiatry 31:915, February 2026.)

Previous post about anxiety, just below: Anxiety. 1. A choline connection (January 28, 2026).

More about microglia and disease:
* Added February 18, 2026. Can a person get both cancer and Alzheimer's disease? (February 18, 2026).
* Alzheimer's disease: a role for inflammation? (January 18, 2020). The post doesn't mention microglia, but one of the news stories listed there does.

My page for Biotechnology in the News (BITN) -- Other topics includes a section on Brain. It includes an extensive list of brain-related Musings posts.

January 2026

Anxiety. 1. A choline connection

January 28, 2026

We have two recent articles on anxiety -- on the biology behind the phenomenon. One reason for the interest is that some people have excessive anxiety responses, which can interfere with normal life. These articles could be steps toward a better understanding of anxiety, including excessive responses. One of them directly leads to considering a common biochemical to see if it might usefully modulate the anxiety response. We'll discuss that article in this post, and the other in the next post, in a few days.

The first article suggests a connection between the nutrient choline and anxiety. The basic finding is that people with anxiety disorders have lower levels of choline in the brain than typical.

That observation is based on magnetic resonance spectroscopy (MRS) measurements of the choline level in the brain. It is a complex measurement. (MRS is related to the more familiar MRI (magnetic resonance imaging).) The article is actually a review of 25 studies on the matter -- with a total of only about 350 people in each group: test and control.

This may be an interesting finding. But the authors stress that the reason for the connection is unknown. It could be an accidental correlation, with minimal functional significance. Scientists will follow up the current work, both trying to understand the connection, and testing whether choline supplements might be of benefit. They do caution that taking chorine supplements at this point would be premature, unless with medical supervision. Choline has complex roles in the body, and is not without risk.

* News story: Low Choline Could Be a Hidden Driver of Anxiety. (Neuroscience News (Lisa Howard, University of California Davis), November 10, 2025.)
* The article (open access): Transdiagnostic reduction in cortical choline-containing compounds in anxiety disorders: a 1H-magnetic resonance spectroscopy meta-analysis. (Richard J Maddock & Jason Smucny, Molecular Psychiatry 30:6020, December 2025.) Review article.

A previous post about the complexity of choline: The importance of choline as a dietary nutrient (April 15, 2023). Again, this is about work with mice.

Added February 4, 2026. Next post about anxiety, just above: Anxiety. 2. An immune system connection (February 4, 2026).

More about anxiety: Should you give Librium -- an anti-anxiety drug -- to crayfish? (October 6, 2014).

My page for Biotechnology in the News (BITN) -- Other topics includes a section on Brain. It includes an extensive list of brain-related Musings posts.

The oldest known RNA

January 14, 2026

A new article reports isolating RNA from a woolly mammoth sample, about 39,000 years old.

That is a surprise. Scientists have developed ways to isolate DNA and protein from very old samples; some examples reported in Musings are listed at the end. However, ancient RNA has been much more elusive. It has seemed likely that most RNA would be degraded by ubiquitous nucleases within hours after death.

It is not clear why the particular sample used here yielded meaningful RNA sequences. Unusually good preservation of the sample, especially immediately after death, is one likely factor. Some technical issues of the isolation procedure also may have contributed.

The work does provide some information about gene function in the woolly mammoth. Some of the RNA could be clearly identified as to the protein it encoded. For example, some of the genes that were active in the muscle sample were muscle genes. Not a very exciting finding, but a start. There was also evidence for expression of genes involved in stress response, suggesting that the animal had been injured.

The article may be of interest mainly for making the step, rather than for any particular findings at this point. It will give impetus to further work looking for RNA in ancient samples. The RNA reported here is more than twice as old than the previous record holder. But it is quite young compared to old DNA and protein that have been found.

* News stories:
- This 39,000-Year-Old Mammoth Holds the World's Oldest Preserved RNA -- An extinct animal's RNA reveals muscle stress in its final moments-after 39,000 years. (Tudor Tarita, ZME Science, November 24, 2025.)
- Scientists recover 40,000-year-old mammoth RNA still packed with clues -- Researchers decoded 40,000-year-old mammoth RNA, unlocking real-time biological secrets frozen since the Ice Age. (Science Daily (Stockholm University), November 15, 2025.)
* The article (open access): Ancient RNA expression profiles from the extinct woolly mammoth. (Emilio Mármol-Sánchez et al, Cell 189:52, January 8, 2026.)

Examples of posts on old molecules...
* Briefly noted... The oldest known sequenced DNA: another new record (December 13, 2022). DNA, two million years old. And the post links to an earlier one about a genome from a million-year-old mammoth.
* Evidence for dinosaur protein extended by a hundred million years (May 12, 2017). Protein, 190 million years old.

Using a tardigrade protein to reduce radiation damage during cancer treatment

January 7, 2026

The tiny animals known as tardigrades (or "water bears") are resistant to various stresses, including radiation. A specific protein has been identified that confers that radiation resistance. It is called Dsup, for damage-suppressor. It binds tightly to DNA, somehow leading to reduced DNA damage during radiation. It seems to be unique to tardigrades.

Previous work showed that human cells engineered to produce that Dsup protein were indeed radiation resistant. That is, the tardigrade protein that reduces radiation damage can function in human cells. No ill effects were seen.

A recent article takes another step toward making real-world use of that tardigrade protein.

The idea is to use the Dsup protein to reduce damage to nearby (healthy) areas when a cancer is being treated with radiation. To do this, the scientists have developed a way to deliver the messenger RNA (mRNA) for Dsup protein to cells in those nearby areas. It is something like an mRNA vaccine, delivered directly to the target area. The mRNA functions, providing radiation resistance to those areas -- without affecting the radiation treatment itself.

Tests in a model system of mouse cancer, reported in the current article, are very encouraging in showing reduced damage from the radiation treatment. Development of this system will continue, with the goal of using it safely in humans during radiation treatment of cancer.

* News story: A protein from tiny tardigrades may help cancer patients tolerate radiation therapy -- When scientists stimulated cells to produce a protein that helps "water bears" survive extreme environments, the tissue showed much less DNA damage after radiation treatment. (Anne Trafton, MIT News, February 26, 2025.)
* The article: Radioprotection of healthy tissue via nanoparticle-delivered mRNA encoding for a damage-suppressor protein found in tardigrades. (Ameya R Kirtane et al, Nature Biomedical Engineering 9:1240, August 2025.)

A recent post on another type of tardigrade resistance: Tardigrade resistance to stress -- how do they do it? (March 27, 2024). Links to more.

Older items are on the archive pages, starting with 2025.

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Last update: February 18, 2026