Day Lila

Mind & Body · Monday, 5 October 2026

01 Briefing what happened

Tau threads from Alzheimer's brains turned a mouse's own tau into the same shape, the way prions spread

Mind & Body 33 sources

Scientists in Cambridge injected tau threads from patients' brains into ordinary mice, and the mice's own tau folded into the patients' shape, which backs the idea that the disease spreads by copying.

9 months

after the injection, the mice had built tau threads from their own protein

A stain that marks only human tau found none of the injected protein left. [1]

20+

brain diseases are marked by threads of tau

Alzheimer's is the most common of them, and different tau diseases have different folds. [1]

57.4m to 152.8m

people with dementia, 2019 and the forecast for 2050

Alzheimer's causes 60% to 80% of cases. [4]

The lead story — what happened

  • Scientists at the MRC Laboratory of Molecular Biology in Cambridge, UK, injected threads of tau protein taken from the brains of people with Alzheimer's disease into the brains of ordinary mice. [1]
  • Tau normally helps build and hold up the inner scaffolding of nerve cells. [3] In Alzheimer's and more than 20 other brain diseases it folds wrongly and stacks into long threads. [1]
  • Nine months later the mice had tau threads that had spread from the injection site to other parts of the brain. [1] They were made of the mouse's own tau, and a stain that only marks human tau found none. [1]
  • Under a microscope powerful enough to show how the protein is folded, the new mouse threads had the same fold as the human seeds. [1] That a tau fold keeps its shape as it passes on had not been shown before. [1][2]
  • The team repeated it with tau from corticobasal degeneration, a rarer brain disease that also damages the brain's support cells. [1] The mice got that disease's fold and its pattern of damage, in support cells as well as nerve cells. [1]
  • This is how prions work. A misfolded prion protein makes normal copies of the protein fold the same wrong way, and those copies then do the same to others. [1] Prions cause Creutzfeldt-Jakob disease, a rare illness that leaves the brain full of holes. [6]
  • Sporadic Creutzfeldt-Jakob disease, the kind with no known cause, strikes about one or two people in a million each year. [5]
  • Earlier mouse models built tau threads with a different shape from the ones in human brains. [1] The authors say ordinary mice can now be used to study how each disease's fold does its damage. [1]
  • Alzheimer's causes 60% to 80% of dementia, which a 2022 study expects to grow from 57.4 million people in 2019 to 152.8 million by 2050. [4]
  • Drugs aimed at tau are already in trials, and some have slowed its build-up on brain scans. [9]
  • How much this copying drives the illness forward in people, rather than in injected mice, is still argued over. [7]
The mouse built the new threads from its own tau, and they came out in the patient's fold.

Who is involved

  • Sofia Lovestam, Michel Goedert and Sjors Scheres

    scientists at the MRC Laboratory of Molecular Biology in Cambridge, UK; they ran the mouse study [1]

  • Kayleigh Mason-Chalmers and Jose Rodriguez

    chemists at the University of California, Los Angeles; they wrote Nature's commentary on the study [2]

How it unfolded

  1. 2021 Microscope studies of human brains show different tau diseases have different folds [1]
  2. 2025 Lovestam, Scheres and Goedert build lab cells whose tau copies the Alzheimer's fold [8]
  3. 30 Sep 2026 The mouse study is published in Nature [2]

Where this points

The next test is whether a drug or antibody that blocks one disease's fold can stop it spreading in these mice, which now copy the fold found in patients' brains. [1][9]

What is pushing on the whole day

The bar and the word are our reading of how hard each one is pushing today. The arrow is where it is heading. The evidence is in the stories below.

Mental health care under strain High↑

A public inquiry into more than 2,000 deaths under Essex mental health care opened new hearings on 5 October. [10] In Israel, children's visits to psychiatric emergency rooms rose 121% in three years of war. [12] Three AI models tested on mental health worries almost never told users to see a clinician. [26]

Health claims running ahead of proof Building↑

Flu jab numbers in Zhejiang, a Chinese province, slowed or fell after two safety scares spread online. [17] Experts told the Guardian there is no such thing as resetting the nervous system, despite the products sold to do it. [21] Herbal eye washes sold in Nigeria held arsenic far above safe limits. [22]

Faster answers from scans and tests Building↑

An NHS genetic test can name a brain tumour's type in under two hours, during surgery. [13] A free program called DeepDisco maps the brain wiring a stroke has cut in under a second. [33]

The rest of the day

20 more stories on this beat.

Each with its own sources. None of these is a link to the story above.

  1. 02

    Essex deaths inquiry hears the regulators

    The Lampard Inquiry is examining the deaths of more than 2,000 people who died under the care of mental health services in Essex, England, between 2000 and the end of 2023. [10] It is an independent inquiry set up under law. [11] New hearings began on 5 October in Chelmsford, with evidence from NHS England, the Care Quality Commission, which inspects care, and the medicines regulator until 15 October. [10] One subject is Oxevision, a camera system that films patients' rooms and records breathing and pulse. [10]

    Why it matters — The chair, Baroness Kate Lampard, said she would make early recommendations on resuscitation and patient monitoring if she found an urgent risk. [10] She said those issues are not specific to Essex, so any recommendation would reach mental health wards across England. [10]

  2. 03

    War doubles PTSD diagnoses in Israel

    Children and teenagers in Israel made 121% more visits to psychiatric emergency departments in the three years after the 7 October 2023 attack than in the two years before, a report by Clalit, Israel's largest health provider, found. [12] Across the population, anxiety diagnoses rose 45.5% and diagnoses of post-traumatic stress disorder (PTSD), lasting distress after a terrifying event, doubled. [12] Among people evacuated from towns near Gaza, PTSD diagnoses were 18 times the pre-war level in the first year and six times in the third. [12]

    PTSD diagnoses among people evacuated from near Gaza, as a multiple of the pre-war level.

    Why it matters — Clalit's mental health director, Yarden Levinsky, said people who were in distress two years ago are still in distress, so the load on clinics is not falling. [12] Evacuees from the north also saw a 60% rise in new high-cholesterol diagnoses. [12]

  3. 04

    A brain tumour named in two hours

    NHS England began a pilot of a fast genetic test for brain tumours on 25 September, starting in five specialist hospitals. [13][14] A small piece of tumour goes into a shoebox-sized machine made by Oxford Nanopore, which reads its DNA as it passes through a tiny hole. [14] The result can reach the surgeon in under two hours, during the operation, instead of the up to eight weeks a microscope diagnosis can take. [14] There are more than 100 types of brain tumour, and each responds to treatment differently. [13]

    The genetic test can name the tumour while the patient is still in the operating theatre.

    Why it matters — Knowing the type during surgery helps the surgeon decide how much tumour to remove while sparing healthy brain. [13] It also lets some patients join trials that require the tumour's genetic make-up. [13]

  4. 05

    Online scares cut flu jabs in China

    Researchers studied every flu jab given in Zhejiang, a province in eastern China, from January 2020 to April 2025, and lined the weekly numbers up against three scares on social media. [17] After rumours in 2022 that a Sinovac vaccine caused lung nodules, weekly growth in jabs slowed from 4.8% to 1.8%. [17] After a 2024 story about a recalled batch of Sanofi Pasteur flu vaccine, jabs went from rising 7.3% a week to falling 9%. [17] A 2024 corruption case against a former Sinopharm engineer changed nothing. [17]

    Weekly change in flu jabs in Zhejiang around a 2024 story about a recalled vaccine batch.

    Why it matters — Free government-funded jabs, which the province gives to older adults, fell in both safety scares. [17] The study shows the timing lined up, which is a link rather than proof that the scares caused the drop. [17]

  5. 06

    Kratom: student deaths and 36,000 comments

    Two students at the University of Mississippi died in September with synthetic kratom-related products found at the scene, though authorities have not said kratom played a part. [19] Kratom is a leaf sold for pain, anxiety and opioid withdrawal; 7-OH is a stronger chemical made from it. [19] In July the US Drug Enforcement Administration proposed listing strong 7-OH in Schedule I, its strictest class. [19] The public comment period closed on 10 September with nearly 36,000 submissions. [19]

    Why it matters — The agency has not said when it will decide, and some states and towns have issued their own bans. [19] A study of US poison centre reports found kratom exposures rose from 19 in 2010 to 1,242 in 2023, with smaller rises in states that ban it. [20]

  6. 07

    Keeping immune cells out slowed brain loss

    Researchers at Washington University in St. Louis treated mice bred to build up tau with an antibody that blocks CXCR3, a molecule T cells use to find damaged tissue. [15] T cells are immune cells, and the antibody kept them from gathering in the brain. [15] Treated mice lost 40% less brain tissue in memory areas and did better on memory tests, though their tau levels were similar. [15] A separate mouse study found the T cells are first switched on outside the brain, in the body's lymph tissue. [16]

    Why it matters — If it holds in people, it would point to a treatment that does not have to get into the brain, as current Alzheimer's drugs must. [15] So far it is only in mice. [15]

  7. 08

    Off their pills, some Parkinson's tests improved

    At Vanderbilt University Medical Center in the US, 19 people with early Parkinson's disease, a brain illness that slows movement, stopped their dopamine medicines for a week. [18] All were aged 50 to 75 and had been treated for one to four years. [18] Off the drugs, they scored better on two harder tests, one of planning and one of thinking speed. [18] Memory, attention and the other tests did not change. [18]

    Why it matters — The authors call the result a lead to test, not a finding, and say a study that varies the order of testing is needed. [18] If it holds, the medicines that help movement may slow some kinds of thinking early in the illness. [18]

  8. 09

    Arsenic in Nigerian herbal eye washes

    Pharmacy researchers at David Umahi Federal University of Health Sciences in Nigeria tested herbal eye cleansers sold for eye irritation and infection. [22] One remedy showed strong antioxidant activity in the lab, a sign it holds active plant compounds. [22] The remedies carried arsenic and cadmium far above the amounts considered safe to take in each day. [22] The arsenic put the cancer risk many times over the accepted limit. [22]

    Why it matters — Lead and copper were within safe limits and no mercury was found, so the danger came from two metals in particular. [22] The authors call for regulation and quality checks on traditional eye remedies. [22]

  9. 10

    There is no nervous system reset

    Tapping, humming, cold plunges and spiky acupressure mats are sold online as ways to reset the nervous system, the Guardian reported on 2 October. [21] Every expert it spoke to said there is no such reset, and nobody should want one. [21] The body needs its fight-or-flight branch to exercise and concentrate, and trouble starts when it does not settle once the demand has passed. [21] Slow breathing at about six breaths a minute is among the best-tested ways to move heart rate variability, a measure of the calming branch's control. [21]

    Why it matters — Cold water first sets off the stress response and calms the body only afterwards. [21] The evidence for acupressure mats is thin, and cheaper, better-tested ways to relax exist. [21]

  10. 11

    AI mental health answers skip the doctor

    Researchers in Canada put 1,350 questions about moderate mental health worries to three open-source AI models, LLaMA, Mistral and DeepSeek. [26] The questions were written as people from a national health survey, using a First Nations mental wellness framework. [26] Crisis-line advice appeared in about 99.6% of answers from two models and 71.3% from DeepSeek. [26] Almost none said they were not medical advice or suggested seeing a clinician. [26]

    Share of answers that included crisis-line advice, out of 450 answers per model.

    Why it matters — Cutting DeepSeek's answers to 180 words dropped its crisis advice to 30%, because the advice came late in the reply. [26] The answers were also written at a harder reading level than is advised for patient leaflets. [26]

  11. 12

    Is a bond with a chatbot attachment?

    Psychologists define an attachment by six conditions set out by Mary Ainsworth: it lasts, the other cannot be replaced, it matters, you want to stay close, separation hurts, and you turn to it for comfort when threatened. [27] An article in Scientific American asks whether bonds with AI companion apps meet them. [27] A survey of 7,027 people in four countries said at least a third of chatbot users showed attachment behaviour. [27] Its three questions never asked whether people turn to the chatbot for comfort when truly distressed. [27]

    Why it matters — The author says the honest answer is that nobody knows yet. [27] The word matters because it shapes how clinicians, parents and regulators read heavy use of these apps. [27]

  12. 13

    Older-looking brains and gut bacteria

    UCLA Health researchers estimated how old the brains of nearly 1,500 adults looked, from scans of how brain areas signal to each other at rest. [23] People whose brains looked older than their age did worse on memory and planning tests and reported more symptoms of depression. [23] In one group, older-looking brains went with particular gut bacteria and their chemical products, including lower levels of a hormone called estetrol. [23] The study was published in eBioMedicine. [23]

    Why it matters — The senior author, Arpana Church, said these signals may show up decades before memory problems appear. [23] The study found a link and did not test whether changing the gut changes the brain. [23]

  13. 14

    Gut bacteria and cancer risk, by genes

    Researchers pooled 39 Mendelian randomisation studies, which use the gene variants people are born with as a natural experiment, to ask whether gut bacteria affect cancer. [28] More Ruminococcaceae bacteria went with about double the risk of urinary-tract cancers and 24% higher cancer risk overall. [28] The same family went with lower lung cancer risk. [28] More Bifidobacteriaceae went with 47% higher bowel cancer risk. [28]

    Why it matters — The authors say so few studies exist that every link needs checking. [28] If the links hold, they may help guide cancer screening in future. [28]

  14. 15

    Cataract and heart disease share genes

    A genetic study compared gene data for cataract, the clouding of the eye's lens, with four kinds of heart disease. [29] It found shared genetic risk with irregular heartbeat, blocked heart arteries and heart failure. [29] There were 924 shared gene variants in 79 places in the genome. [29] Genes such as APOE pointed to how the body handles cholesterol. [29]

    Why it matters — It offers one reason these two illnesses of ageing turn up in the same people. [29] The authors call the genes candidates to test, not proven causes. [29]

  15. 16

    Tuberculosis keeps moving in South Sulawesi

    Researchers mapped reported tuberculosis, a lung infection, across 24 districts of South Sulawesi, a province of Indonesia, from 2018 to 2023. [30] Reported cases rose overall, and the gap between districts widened. [30] The worst-hit districts kept changing from year to year instead of staying the same. [30] Districts with more years of schooling and higher unemployment reported more cases. [30]

    Why it matters — A list of high-burden districts drawn one year could be wrong the next. [30]

  16. 17

    A 20-minute walk got the gut moving

    At Fujita Health University in Japan, 21 healthy young adults walked on a treadmill for 20 minutes at their own pace. [24] Researchers recorded their bowel sounds with an electronic stethoscope, because the sounds come from gas and fluid being pushed along the gut. [24] Within one to two minutes of stopping, the loudness of the sounds nearly doubled and they came more often. [24] The effect faded within two to three minutes. [24]

    Why it matters — It may help explain why walking is often recommended for constipation. [24] The volunteers were healthy, so the study did not test people who are constipated. [24]

  17. 18

    What marathon training does to a body

    NPR reporter Elissa Nadworny had a bone scan, blood tests and a treadmill test at Ball State University's Human Performance Lab before training for the New York City Marathon in November. [25] Scott Trappe, who runs the lab, said training raises blood volume and improves heart and muscle health over about three months. [25] A UK study NPR cited scanned marathon runners' knees and found cartilage and bone improved during four months of training. [25] Cartilage behind the kneecap was worse just after the race and recovered by six months. [25]

    Why it matters — About a million people try a marathon each year, NPR says. [25] The risk Trappe named was overuse injury, and her bone scan showed strong bones. [25]

  18. 19

    Mapping stroke damage in a second

    Researchers released DeepDisco, a free program that estimates which brain wiring a stroke or other injury has cut, from an outline of the damage. [33] It takes under a second per injury, where the usual method needs heavy computing, special scans and expertise many places lack. [33] Its maps matched the usual method well across the whole brain, less exactly for single kinds of fibre. [33] Used to predict recovery, it explained up to 64% of the differences in movement scores. [33]

    Why it matters — Which wiring an injury cuts helps explain what a person loses, such as movement or thinking. [33] The program is free and runs on any common computer system. [33]

  19. 20

    One gut parasite subtype and IBS

    Blastocystis is a common gut parasite in people, and it has been linked to irritable bowel syndrome (IBS), a long-lasting gut disorder. [31] Researchers in Hamadan, western Iran, typed it in 28 stool samples, 14 from people with IBS and 14 without. [31] Subtype 3 was found in 12 of the 14 people with IBS. [31] Subtype 1 was most common in the people without it. [31]

    Why it matters — The authors call the result preliminary, because only 28 of 80 samples could be typed. [31] Every sample in the study carried the parasite, so the difference lay in the subtype. [31]

  20. 21

    Knowing about obesity did not track weight

    A study of 123 adults aged 30 to 60 measured body mass index, waist and hip size, and asked about awareness of obesity. [32] None of the body measures tracked overall awareness. [32] People with overweight scored higher on one part of the test than people with obesity. [32] Having a family member with obesity, and a person's job, went with awareness. [32]

    Why it matters — In this small sample, knowing about obesity and having it were separate things. [32] The study was a single snapshot, so it cannot say which came first. [32]

02 Lesson why it matters

A misfolded protein passes on its shape, with no gene involved

A wrong-shaped protein presses healthy copies into its own fold, so a brain disease can spread from cell to cell without changing.

The twist

The mouse made its tau from its own genes, yet the new threads matched the patient's threads. What set them was the thread the tau touched, not the gene that made it.

The picture

The same kind of mouse got two different patterns of damage, because the two seeds had two different folds.

How it works

  1. Tau normally helps hold up the inside of nerve cells
  2. In disease it folds wrongly and stacks into threads
  3. The end of a thread works like a mould for normal tau
  4. Each new piece joins and takes the same fold
  5. Threads break and reach nearby cells, starting new moulds
  6. So the disease spreads and keeps its own fold

Where you've seen this

Mad cow disease

a misfolded prion protein in cattle feed made the cows' own prion protein fold wrongly too

Rock candy

sugar from a syrup builds onto a seed crystal in the crystal's own pattern

Frost on a window

ice spreads out from the first crystals and copies their pattern across the glass

The catch

The mice were given a dose of ready-made threads; in people, what starts the first wrong fold, and how much the copying drives the illness forward, is still unknown.

And the whole of it

Every one of us carries tau in our nerve cells, so this is about a protein we all have. Families caring for someone with dementia see where the spread ends. The scientists can so far watch the copying only in mice.

03 Truth what's really going on

What is really going on

Scientists in Cambridge showed that tau threads from human brains turn a mouse's own tau into the same fold, which is new support for the idea that Alzheimer's spreads through the brain the way prions do. [1][2] Much of the rest of the day is about safety decided with poor information. The US drug agency is still weighing 7-OH after 36,000 comments, flu jabs in a Chinese province fell after online scares, and herbal eye washes sold in Nigeria held arsenic. [19][17][22]

Who gains

  • Researchers testing drugs against tau — Ordinary mice now build tau threads in the patient's own fold, which earlier mouse models did not, so a drug can be tested against one disease's fold in a mouse. [1]
  • Oxford Nanopore, a UK maker of DNA-reading machines — Its shoebox-sized sequencer is the machine inside the NHS brain tumour test now running in five hospitals. [14]
  • Sellers of milder kratom leaf products — The US proposal covers only 7-OH above a potency threshold, so milder natural kratom products would stay outside the strictest class. [19]
  • Sellers of acupressure mats, vibrating plates and similar gadgets — They are marketed online as ways to reset the nervous system, which every expert the Guardian asked said cannot be done. [21]

Who pays

  • Patients and families of Essex mental health services — More than 2,000 deaths from 2000 to 2023 are under examination, and the final report is not due until 2028. [10]
  • Children evacuated from southern Israel — Prescriptions for bed-wetting medicine rose 47.8%, and PTSD diagnoses among evacuees from near Gaza were still six times the pre-war level in the third year. [12]
  • People in Nigeria who use herbal eye cleansers — The remedies tested held arsenic and cadmium far above the amount considered safe to take in each day. [22]
  • Older people in Zhejiang who rely on free flu jabs — Government-funded jabs, which the province gives to older adults, fell during both safety scares. [17]
  • People dependent on 7-OH — Addiction experts told STAT that a Schedule I listing would leave them facing withdrawal if supply stops, or prosecution if it does not. [19]

What nobody knows yet

Open questions from across today’s stories — ours included.

  • 01

    Whether tau spreads this way inside people's brains.

    The study injected human tau into mice and looked nine months later. [1] A review argues it is still unclear how much this copying drives the common forms of these illnesses that are not inherited. [7]

  • 02

    What makes tau fold wrongly in the first place.

    The study shows how a wrong fold spreads once it exists, using threads taken from patients. It does not show what starts the first one. [1]

  • 03

    Whether the Lampard Inquiry will issue early recommendations.

    Baroness Lampard will decide after families give their views on 20 October, and the final report is not due until 2028. [10]

  • 04

    Whether camera monitoring like Oxevision makes mental health wards safer.

    LIO Health, which makes it, says it prevents serious incidents. The mother of Sophie Alderman, who died in 2022, told the inquiry it takes away human contact. [10]

  • 05

    When the US drug agency will decide on 7-OH.

    Public comments closed on 10 September with nearly 36,000 submissions, and no date for a decision has been given. [19]

  • 06

    Whether the online scares caused the fall in flu jabs in Zhejiang.

    The study shows the drops lined up in time with the scares, which the authors describe as an association. [17]

  • 07

    Whether stopping Parkinson's medicines really sharpens planning and speed.

    Only 19 people took part, and the authors say a study that varies the order of testing is needed before the result can be trusted. [18]

  • 08

    How much of Israel's rise in PTSD is new trauma and how much is people coming forward late.

    Clalit's Yarden Levinsky said a new PTSD diagnosis can relate to an event six months or five years earlier. [12]

  • 09

    Whether keeping T cells out of the brain would help people with Alzheimer's.

    The 40% smaller loss of brain tissue was seen in mice only. [15]

04 Hope carry this

A surgeon in England can now learn which kind of brain tumour a patient has in under two hours, during the operation, where a diagnosis used to take up to eight weeks. Five hospitals began using the genetic test in September.

Also true today

  • In a UK scanning study, marathon runners' knee cartilage and bone got better during four months of training. The strain seen just after the race was gone six months later.
  • Mice whose immune T cells were kept out of the brain lost 40% less brain tissue in their memory areas.

Across the beats