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Published14 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy Nick TriggleHealth correspondentEnd-of-life care has not become worse in countries which have allowed assisted dying, MPs say.The House of Commons’ Health and Social Care Select Committee said there is even evidence it has led to better support with more money being invested.But the cross-party group of MPs did not rule in favour or against a change in the law in England, saying it only wanted to inform debate.It said hospices here needed extra money as access to care was patchy.Currently hospices only receive a third of their funding from the NHS, despite providing the majority of the palliative care.What is assisted suicide and euthanasia?Starmer supports assisted dying law change The committee’s review looked at places where assisted dying for the terminally ill is allowed, including parts of the US, as well as Australia, Switzerland and New Zealand.In England and Wales, the 1961 Suicide Act makes it an offence to encourage or assist someone to take their own life.Separate laws in Scotland and Northern Ireland prevent dying people asking for medical help to die.Despite some expressing concern that a change in the law would lead to poorer support at the end of life, the committee’s report said, if anything, it was linked to improvement in the countries which have taken the step, with evidence showing the alterations resulted in extra investment in palliative care.The issue has been in the spotlight in recent months, with Dame Esther Rantzen revealing she has joined the Dignitas assisted dying clinic in Switzerland.The 83-year-old Childline founder and broadcaster, who has stage four cancer, has called for a free vote for MPs in Parliament.She told BBC Breakfast people should have a choice about “the way we want to end our lives”.”We don’t want our families memories to be overwhelmed by the memory of us in pain, suffering.”She added she had a “very narrow choice” as if she wanted to end her life and go to Dignitas she would have to do it without her family there as they could be accused of conspiring to bring about her death.Over the last eight years, more than 250 people have travelled to Dignitas to end their lives, according to the clinic.’Law change would give dying control’Sophie Blake was diagnosed with stage four breast cancer in 2020 when she was 49. The cancer has spread to her lungs, liver, abdominal lymph nodes and pelvis and is incurable.She has always supported people’s choice to end their lives after seeing friends and family die in pain.”I always thought that’s so cruel, why would we subject people to end up in so much untreatable pain when the meds can’t even touch the sides because we’re not allowed to help them [end their lives]?”Since her diagnosis, Sophie says she is hoping for the best, while preparing for the worst. A priority for her is that her 16-year-old daughter Maya does not see her suffer.”I don’t want that to be her lasting memories, seeing her mum in horrendous pain,” she says.Sophie says knowing there was a choice to end life would help many terminal patients.”So many people would benefit psychologically knowing that there would be a form of help when the time comes if needed,” she said.”It would give you that final control at the very end, to have a good death rather than a death of suffering.”The committee also highlighted problems and confusion with the way the current system works for doctors, saying it was not clear whether they could provide medical evidence for people who wanted to go abroad to die.Guidance from the General Medical Council says providing access to patient records is allowable under the Data Protection Act.But the British Medical Association (BMA) advises doctors against producing medical reports to facilitate assisted suicide.It also said the government needed to consider how it would handle changes in the law in places such as the Isle of Man and Jersey, which are currently considering the issue.Select Committee chairman Steve Brine said he wanted the report to have a “lasting legacy” by providing evidence for future debates on the law.But he said assisted dying was the “most complex” issue at which the committee had looked.The report pointed out that even what term to use is contested, with the committee referring to it as assisted dying/assisted suicide. It defined this as doctor-assisted deaths, including self-administration of a lethal drug as well as where the doctor gives it, which is often referred to as euthanasia.Both the BMA and Royal College of Nursing have neutral positions on assisted dying.The government says any change is a matter for Parliament – and has indicated it would allow a free vote on it. Numerous attempts have been made to alter the law over the years – the most recent in 2021. The law has also been challenged in the courts, with a number of people with terminal and life-limiting illnesses putting their case for a right to die.Dr Gordon Macdonald, of anti-assisted dying campaign group Care Not Killing, said he was disappointed the committee did not come out against assisted dying.He said he believed there were “many problems” with changing the law, including that limits on who qualifies could in time be lifted to include people with disabilities, those with non-terminal health conditions and problems such as dementia and depression.The MPs should have “firmly shut the door” on “state-sanctioned killing”, he added.

A new study analyzed several years of surveys on increases in marijuana and cannabis consumption.People who frequently smoke marijuana have a higher risk of heart attack and stroke, according to a study published on Wednesday.The article, published in The Journal of the American Heart Association, is an analysis of responses to the U.S. government’s annual survey on behavioral risk from 2016 to 2020.The respondents answered health questions, including reporting their own health problems related to heart disease.About 4 percent of the respondents reported daily marijuana use, which the researchers suggested raised the chance of a heart attack by 25 percent and of a stroke by 42 percent. Among those who never smoked tobacco, daily use was tied to a 49 percent higher risk of heart attack and a more than doubled risk of stroke, the study indicated.About three-quarters of the respondents said that smoking was their main method of using weed. The other quarter consumed it by vaping, through edibles or drinking it.“Cannabis smoke releases the same toxins and particulate matter that tobacco does,” said the study’s first author, Abra M. Jeffers, a data analyst at Massachusetts General Hospital in Boston. She conducted the analysis during her post-doctoral fellowship at the University of California, San Francisco.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

People with long Covid symptoms scored slightly lower on a cognitive test than people who had recovered. But patients who had recovered scored as well as those who had only short-term Covid symptoms.Long Covid may lead to measurable cognitive decline, especially in the ability to remember, reason and plan, a large new study suggests.Cognitive testing of nearly 113,000 people in England found that those with persistent post-Covid symptoms scored the equivalent of 6 I.Q. points lower than people who had never been infected with the coronavirus, according to the study, published Wednesday in The New England Journal of Medicine.People who had been infected and no longer had symptoms also scored slightly lower than people who had never been infected, by the equivalent of 3 I.Q. points, even if they were ill for only a short time.The differences in cognitive scores were relatively small, and neurological experts cautioned that the results did not imply that being infected with the coronavirus or developing long Covid caused profound deficits in thinking and function. But the experts said the findings are important because they provide numerical evidence for the brain fog, focus and memory problems that afflict many people with long Covid.“These emerging and coalescing findings are generally highlighting that yes, there is cognitive impairment in long Covid survivors — it’s a real phenomenon,” said James C. Jackson, a neuropsychologist at Vanderbilt Medical Center, who was not involved in the study.He and other experts noted that the results were consistent with smaller studies that have found signals of cognitive impairment.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

A collaborative research endeavor by scientists in the Departments of Radiology, Neurology, and Psychology and Neuroscience at the UNC School of Medicine have demonstrated the deleterious effects of chronic cocaine use on the functional networks in the brain.
Their study titled “Network Connectivity Changes Following Long-Term Cocaine Use and Abstinence,” was highlighted by the editor of Journal of Neuroscience in “This Week in The Journal.” The findings show that continued cocaine use affects how crucial neural networks communicate with one another in the brain, including the default mode network (DMN), the salience network (SN), and the lateral cortical network (LCN).
“The disrupted communication between the DMN and SN can make it harder to focus, control impulses, or feel motivated without the drug,” said Li-Ming Hsu, PhD, assistant professor of radiology and lead author on the study. “Essentially, these changes can impact how well they respond to everyday situations, making recovery and resisting cravings more challenging.”
Hsu led this project during his postdoctoral tenure at the Center for Animal MRI in the Biomedical Research Imaging Center and the Department of Neurology. The work provides new insights into the brain processes that underlie cocaine addiction and creates opportunities for the development of therapeutic approaches and the identification of an imaging marker for cocaine use disorders.
The brain operates like an orchestra, where each instrumentalist has a special role crucial for creating a coherent piece of music. Specific parts of the brain need to work together to complete a task. The DMN is active during daydreams and reflections, the SN is crucial for attentiveness, and the CEN, much like a musical conductor, plays a role in our decision-making and problem-solving.
The research was motivated by observations from human functional brain imaging studies suggesting chronic cocaine use alters connectivity within and between the major brain networks. Researchers needed a longitudinal animal model to understand the relationship between brain connectivity and the development of cocaine dependence, as well as changes during abstinence.
Researchers employed a rat model to mimic human addiction patterns, allowing the models to self-dose by nose poke. Paired with advanced neuroimaging techniques, the behavioral approach enables a deeper understanding of the brain’s adaptation to prolonged drug use and highlights how addictive substances can alter the functioning of critical brain networks.

Hsu’s research team used functional MRI scans to explore the changes in brain network dynamics on models that self-administrated cocaine. Over a period of 10 days followed by abstinence, researchers observed significant alterations in network communication, particularly between the DMN and SN.
These changes were more pronounced with increased cocaine intake over the 10 days of self-administration, suggesting a potential target for reducing cocaine cravings and aiding those in recovery. The changes in these networks’ communication could also serve as useful imaging biomarkers for cocaine addiction.
The study also offered novel insights into the anterior insular cortex (AI) and retrosplenial cortex (RSC). The former is responsible for emotional and social processing; whereas, the latter controls episodic memory, navigation, and imagining future events. Researchers noted that there was a difference in coactivity between these two regions before and after cocaine intake. This circuit could be a potential target for modulating associated behavioral changes in cocaine use disorders.
“Prior studies have demonstrated functional connectivity changes with cocaine exposure; however, the detailed longitudinal analysis of specific brain network changes, especially between the anterior insular cortex (AI) and retrosplenial cortex (RSC), before and after cocaine self-administration, and following extended abstinence, provides new insights,” said Hsu.

Scientific advisers to the C.D.C. recommended boosters for Americans ages 65 and older.Americans ages 65 and older should receive an additional dose of the latest Covid vaccine this spring, scientific advisers to the Centers for Disease Control and Prevention said on Wednesday.The spring shot would be a second dose of the most recent iteration of the Pfizer-BioNTech, Moderna or Novavax vaccines introduced in the fall. The recommendation now goes to the C.D.C. director, Dr. Mandy Cohen, who is likely to accept it.At a meeting of the agency’s Advisory Committee on Immunization Practices, federal researchers presented preliminary data showing that the latest vaccines have an effectiveness of about 40 to 50 percent against symptomatic infection or hospitalization, although estimates against currently circulating variants were based on small numbers.In October and November, adults who received a fall dose accounted for 4 percent of Covid-related hospitalizations. Those who got a booster in the fall of 2022, but not the updated vaccine this fall, accounted for 25 percent.Still, a second dose this spring would not be cost-effective for adults 18 to 64 years old, who are at lower risk of severe illness and hospitalization than older adults, according to modeling presented at the meeting. Older adults and those with weakened immune systems because of illnesses or medications would benefit the most from a spring dose, the advisers concluded.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

Neuroscientists at Fred Hutchinson Cancer Center have found that an often-overlooked type of brain cell called glia has more of a role in brain function than previously thought.
In the journal Cell Reports, Fred Hutch neuroscientist Aakanksha Singhvi, PhD, and her team report that a single glial cell uses different molecules to communicate with different neurons. Careful clustering of these molecules ensures that the glial cell can conduct a distinct “conversation” with each neuron. Through these molecular facilitators, glia can influence how neurons respond to environmental cues like temperature and smell.
Cell Reports published the study online Feb. 27.
“It’s the first very clear indication that a glial cell is going to put specific molecules to specific contact sites to regulate those neurons, at the single-cell level, with consequences to how the animal will behave,” said Singhvi, who is an assistant professor in the Basic Sciences Division at Fred Hutch.
Glial cells make up about half of the cells in the brain, but the other half of the cells — neurons — typically get the most of our attention for their central role in our thoughts, sensations and behaviors. Less glitzy than neurons that literally pulse with electricity, glia seemed to play a purely supporting role. Neuroscientists dismissed them a mere “glue” that help neurons stick together, or “nursemaids” that provide neurons sustenance but not guidance.
Singhvi is among the cadre of neuroscientists leading the charge to reevaluate the importance of glia.
“In the last few years there has been growing appreciation that glial cells may contribute to many diseases of the brain, from epilepsy to Alzheimer’s,” Singhvi said. “To have a more holistic and clinically-relevant picture of brain function, we need to go back to basics and more fully understand how glia and neurons work together.”
To unearth glial cells’ basic biology, Singhvi helped develop the use of Caenorhabditis elegans, which are tiny, transparent worms (also called nematodes). Each worm has exactly the same number of cells, including 302 neurons per animal, and only 56 glia. While we may seem to have little in common with worms, their neurons and glia work much like ours.

Singhvi and Sneha Ray — first author of the Cell Reports study and a graduate student in Singhvi’s lab — focused on one of these glial cells called amphid sheath (AMsh) to see how they interacted with a sensory neuron called AFD, which senses temperature for C. elegans.
Using high-powered microscopes to zero in on individual neurons and glia, the researchers looked for a protein called KCC-3 that Singhvi had previously discovered helps with signaling across cell membranes. The researchers quickly saw that KCC-3 was not distributed equally along the glial cell’s membrane. Instead, the protein clustered in one spot along the interface between the glial cell (AMsh) and the sensory neuron (AFD).
“We realized it’s sitting next to the temperature-sensing neuron — but not any of the others — which is essentially the glial cell knowing a half a micron [millionth of a meter] difference between the two neurons,” Singhvi said.
The team detected at least three types of molecular clusters that connect the AMsh glia to different sensory neurons.
Ray and Singhvi also found that even though every neuron enveloped by AMsh senses a different environmental cue, the glial cell can help integrate information across circuits and allow neurons within one sensory circuit (like temperature) to influence the function of neurons within a different circuit (like those that smell specific odors). In this way, a single glial cell can help the worm respond to the bigger environmental picture, instead of merely helping neurons relay individual external cues.
“When you think about what it takes to be a nematode, it’s very complicated,” Singhvi said.

What does a worm do when it encounters a tantalizing scent that signals food — right when its environment starts getting dangerously warm? It must balance these different inputs and make a decision.
“The worm won’t burn — it’s too smart to burn,” Singhvi said.
And the compartmentalization that she and Ray uncovered is likely critical to a nematode’s — or human’s — ability to weigh important factors like heat and smell, she said. This allows the animal to have multiple circuits working properly at the same time without confusing cross connections.
For possible applications to human brain health, Singhvi noted that the same KCC-3 protein she studies in nematodes is also essential for brain function in humans. Disruptions of KCC-3 is linked to a severe brain development disorder called agenesis of the corpus callosum or Anderman Syndrome, and to seizure susceptibility and neurodegeneration. Differences in brain circuits is linked to conditions such as autism, epilepsy and schizophrenia.
“Our brains routinely process multiple inputs or sensory cues in parallel,” Singhvi said. “Our research showing that glia can be conduits between brain circuits will help us understand the different ways that the circuits can be disrupted.”
This work was funded by the National Institute of Neurological Disorders and Stroke, the Simons Foundation, Barbara Stephanus, George Brown, the Van Sloun Foundation, the Esther A. & Joseph Klingenstein Fund, the Glenn Foundation for Medical Research, the American Federation for Aging Research and the Brain Research Foundation.

Scientists have extensively researched the structure and sequence of genetic material and its interactions with proteins in the hope of understanding how our genetics and environment interact in diseases. This research has partly focused on ‘epigenetic marks’, which are chemical modifications to DNA, RNA, and the associated proteins (known as histones).
Epigenetic marks influence when and how genes get switched on or off. They can also instruct cells about how to interpret and use genetic information, influencing various cellular processes. Changes in epigenetic marks therefore significantly impact gene regulation and cellular functions, which means they might contribute to disease. By studying epigenetic marks, researchers can clarify their role in health and disease and potentially discover new avenues for treatment.
While researchers can identify and compare epigenetic marks, understanding the correlation between specific modifications and how genes work has remained challenging. To help overcome this, Dr Dan Ohtan Wang and Dr Kandarp Joshi have created a new tool called epidecodeR. The user-friendly tool, published in Briefings in Bioinformatics, enables biologists to quickly check if a modification affects how a gene responds in specific situations.
“If a positive correlation is found, this could motivate scientists to confirm the findings, helping them understand the role of these gene modifications in various conditions, including cancer and neurological disorders,” explains Joshi, a researcher at the Institute for Integrated Cell-Material Sciences (iCeMS).
The team used statistical methods to categorize groups of genes based on how many modifications they had. They showed that EpidecodeR can predict the role of specific modifications, such as altering certain proteins or using drugs, and how these could impact gene activity.
“We used epidecodeR to successfully predict how a protein called histone deacetylase affects the activity of genes,” says Wang, a visiting professor at iCeMS who led the study. “We also found epidecodeR to be effective in identifying substances that can block another protein, called RNA demethylase, and we explored how changes in proteins called histones might be related to drug abuse.”
The researchers plan to conduct further studies to improve epidecodeR’s accuracy and specificity. “We want to include more details concerning where, how, and how many modifications occur in genes,” says Joshi. “As the data becomes more complex, we also aim to provide users with various statistical tests to enhance the capabilities of the tool.”

New research from the University of British Columbia reveals a safe path to overcoming food allergies for older children and others who can’t risk consuming allergens orally to build up their resistance.
It’s called sublingual immunotherapy (SLIT), and it involves placing smaller amounts of food allergens under the tongue.
A study conducted by UBC clinical professor and pediatric allergist Dr. Edmond Chan and his team at BC Children’s Hospital Research Institute found SLIT to be as safe and effective for high-risk older children and adolescents as oral immunotherapy is for preschoolers.
“Our work confirms the safety and effectiveness of SLIT for older children and adolescents with multiple food allergies at higher risk of severe reaction,” said Dr. Chan. “These are patients for whom oral immunotherapy would typically be denied because it’s felt to be too risky, so this could be the best approach for that population.”
Previously published research from Dr. Chan’s team has shown that preschool oral immunotherapy is safe and effective in the real world. The protocol involves a “build-up phase” of several months, when patients visit a clinic every two weeks to ingest a higher dose of an allergen under medical supervision before continuing the same daily dose between visits. When they reach a certain dose — usually around 300 mg of protein — they enter a “maintenance phase” during which they take that target daily dose at home. After a year of maintenance doses, approximately four out of five patients are able to pass an oral challenge test in which they tolerate a much higher dose of 4,000 mg of protein.
However, the build-up phase is risky for older children and those with a history of severe reactions. Dr. Chan’s group has been looking for a safer way to get this at-risk group of patients to the maintenance phase.
They recruited about 180 such patients between the ages of four and 18, most with multiple food allergies. The SLIT protocol (started when COVID-19 pandemic restrictions were in place) required patients to have virtually supervised appointments 3-5 times over several months to build up to a small dose — in most cases, just 2 mg of protein — which is absorbed through the membranes under the tongue rather than swallowed and ingested.

The patients’ caregivers learned how to mix and administer these doses at home using novel recipes based on products you can buy at the grocery store, developed with the team’s research dietitian. A wide variety of allergens were treated, including peanut, other legumes, tree nuts, sesame, other seeds, egg, cow’s milk, fish, wheat, shrimp, and other allergens. Patients took these doses daily for 1-2 years.
“It takes up to twice as long as oral immunotherapy, but we wouldn’t have had it any other way, because we needed the superior safety of SLIT for these older kids that are felt to be more severe,” said Dr. Chan.
While most patients had mild symptoms during the build-up phase, none had severe reactions during either build-up or maintenance. Seventy per cent of those tested at the end of the protocol could tolerate 300 mg of their allergen — a success rate nearly as high as that for oral immunotherapy.
The results were encouraging for a therapy that any family can undertake at home with guidance from professionals.
“Besides safety considerations in older children, allergists are often quite burdened by the oral immunotherapy build-up phase, where a patient may require 11 or more visits to the clinic. They just don’t feel they have the capacity to offer that many visits in their office,” said Dr. Chan. “In our clinic, we are starting to do more home-based approaches because the demand for medical appointments that would allow supervision far outstrips the supply. We are trying to develop an approach, based on data, that matches a patient’s risk level with the appropriate amount of supervision. Our SLIT data suggests that home-based SLIT build-up is safe.”
Ultimately, the trial highlights an alternative that allergists should now consider for patients who cannot safely undertake oral immunotherapy. The trade-off for greater safety is simply a longer timeline, but it comes with the benefit of keeping clinics free for those who need them most.
The study was published this week in The Journal of Allergy and Clinical Immunology.

Published10 minutes agoShareclose panelShare pageCopy linkAbout sharingImage source, Getty ImagesBy Michelle RobertsDigital health editorFewer smokers in England now see vaping as less harmful than cigarettes, despite evidence tobacco is far worse for health and e-cigarettes can help smokers quit, data suggests.Perceptions are shifting, according to survey responses from more than 28,000 current smokers between 2014 and 2023.The latest round of results found 57% thought vaping just as harmful as smoking or more so.Ideally, people should neither vape nor smoke, the NHS says. NHS: Is vaping harmful?Vaping exposes users to far fewer toxins and at lower levels than smoking cigarettes.Cigarettes release thousands of different chemicals when they burn. Many are poisonous and up to 70 cause cancer. They also cause other serious illnesses, including lung disease, heart disease and stroke. Most of the harmful chemicals in tobacco smoke, including tar and carbon monoxide, are not in vape aerosol.But vaping is not risk-free. And the NHS advises non-smokers and young people under the age of 18 not to start.Common side effects of vaping include:coughing, dry mouth and throatmouth and throat irritationshortness of breathheadachesThe data, published in the journal JAMA Network Open comes from a Cancer Research UK-funded weekly survey running since 2006 to track national smoking patterns and inform stop-smoking policies. In November 2014:44% of smokers thought vaping less harmful than smoking11% more so30% equally harmful15% did not knowBut by June 2023:only 27% thought vaping less harmful23% more so34% equally harmful16% did not knowIt’s not clear what is behind the trends – the study didn’t look at that. But stop smoking experts are concerned.One of the researchers, Dr Sarah Jackson, from University College London (UCL), said: “These findings have important implications for public health. “The risks of vaping are much lower than the risks of smoking – and this isn’t being clearly communicated to people.”This misperception is a health risk in and of itself, as it may discourage smokers from substantially reducing their harm by switching to e-cigarettes. “It may also encourage some young people who use e-cigarettes to take up smoking for the first time, if they believe the harms are comparable.”Better communication about the health risks is needed so that adults who smoke can make informed choices about the nicotine products they use.”How dangerous is vaping?Vape safety message luring in children, says expertHow do you quit vaping?Prof Jamie Brown, also from UCL, said: “E-cigarettes are novel and so have attracted much attention in the media, with news articles often overstating their risks to health compared with smoking. “There is relatively little reporting about deaths caused by smoking, even though 75,000 people die as a result of it in England each year.”The government plans to offer one million smokers a free vaping starter kit alongside behavioural support to help them quit. “This initiative may be undermined if many smokers are unwilling to try e-cigarettes because they wrongly believe them to be just as harmful as cigarettes or more so.”Action on Smoking and Health (Ash) chief executive Deborah Arnott said “scare stories” about young people vaping could be causing the growing misconception among adult smokers that vaping was at least as risky as smoking. “There are millions of smokers who may, as a result, never try the most effective and easily available quitting aid, the e-cigarette,” she said.”The tragedy is that as a result many smokers may carry on smoking when they could have quit, continuing to put themselves at serious risk of cancers, respiratory and heart disease, followed by premature death.” More on this storyHow do you quit vaping?Published24 May 2023How dangerous is vaping and what is the disposable vape ban?Published1 day agoRelated Internet LinksVaping to quit smoking – NHSJAMA Network OpenThe BBC is not responsible for the content of external sites.

There lies a paradox in sleep. Its apparent tranquility juxtaposes with the brain’s bustling activity. The night is still, but the brain is far from dormant. During sleep, brain cells produce bursts of electrical pulses that cumulate into rhythmic waves — a sign of heightened brain cell function.
But why is the brain active when we are resting?
Slow brain waves are associated with restful, refreshing sleep. And now, scientists at Washington University School of Medicine in St. Louis have found that brain waves help flush waste out of the brain during sleep. Individual nerve cells coordinate to produce rhythmic waves that propel fluid through dense brain tissue, washing the tissue in the process.
“These neurons are miniature pumps. Synchronized neural activity powers fluid flow and removal of debris from the brain,” explained first author Li-Feng Jiang-Xie, PhD, a postdoctoral research associate in the Department of Pathology & Immunology. “If we can build on this process, there is the possibility of delaying or even preventing neurological diseases, including Alzheimer’s and Parkinson’s disease, in which excess waste — such as metabolic waste and junk proteins — accumulate in the brain and lead to neurodegeneration.”
The findings are published Feb. 28 in Nature.
Brain cells orchestrate thoughts, feelings and body movements, and form dynamic networks essential for memory formation and problem-solving. But to perform such energy-demanding tasks, brain cells require fuel. Their consumption of nutrients from the diet creates metabolic waste in the process.
“It is critical that the brain disposes of metabolic waste that can build up and contribute to neurodegenerative diseases,” said Jonathan Kipnis, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Pathology & Immunology and a BJC Investigator. Kipnis is the senior author on the paper. “We knew that sleep is a time when the brain initiates a cleaning process to flush out waste and toxins it accumulates during wakefulness. But we didn’t know how that happens. These findings might be able to point us toward strategies and potential therapies to speed up the removal of damaging waste and to remove it before it can lead to dire consequences.”
But cleaning the dense brain is no simple task. Cerebrospinal fluid surrounding the brain enters and weaves through intricate cellular webs, collecting toxic waste as it travels. Upon exiting the brain, contaminated fluid must pass through a barrier before spilling into the lymphatic vessels in the dura mater — the outer tissue layer enveloping the brain underneath the skull. But what powers the movement of fluid into, through and out of the brain?

Studying the brains of sleeping mice, the researchers found that neurons drive cleaning efforts by firing electrical signals in a coordinated fashion to generate rhythmic waves in the brain, Jiang-Xie explained. They determined that such waves propel the fluid movement.
The research team silenced specific brain regions so that neurons in those regions didn’t create rhythmic waves. Without these waves, fresh cerebrospinal fluid could not flow through the silenced brain regions and trapped waste couldn’t leave the brain tissue.
“One of the reasons that we sleep is to cleanse the brain,” Kipnis said. “And if we can enhance this cleansing process, perhaps it’s possible to sleep less and remain healthy. Not everyone has the benefit of eight hours of sleep each night, and loss of sleep has an impact on health. Other studies have shown that mice that are genetically wired to sleep less have healthy brains. Could it be because they clean waste from their brains more efficiently? Could we help people living with insomnia by enhancing their brain’s cleaning abilities so they can get by on less sleep?”
Brain wave patterns change throughout sleep cycles. Of note, taller brain waves with larger amplitude move fluid with more force. The researchers are now interested in understanding why neurons fire waves with varying rhythmicity during sleep and which regions of the brain are most vulnerable to waste accumulation.
“We think the brain-cleaning process is similar to washing dishes,” neurobiologist Jiang-Xie explained. “You start, for example, with a large, slow, rhythmic wiping motion to clean soluble wastes splattered across the plate. Then you decrease the range of the motion and increase the speed of these movements to remove particularly sticky food waste on the plate. Despite the varying amplitude and rhythm of your hand movements, the overarching objective remains consistent: to remove different types of waste from dishes. Maybe the brain adjusts its cleaning method depending on the type and amount of waste.”