A peek inside human brain shows a way it cleans out waste

A unique peek inside the human brain may help explain how it clears away waste like the kind that leads to Alzheimer's disease

By LAURAN NEERGAARD AP Medical Writer

October 7, 2024, 5:57 PM ET

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WASHINGTON – A unique peek inside the human brain may help explain how it clears away waste like the kind that can build up and lead to Alzheimer’s disease.

Brain cells use a lot of nutrients which means they make a lot of waste. Scientists have long thought the brain has special plumbing to flush out cellular trash, especially during sleep – they could see it happening in mice. But there was only circumstantial evidence of a similar system in people.

Now researchers have finally spotted that network of tiny waste-clearing channels in the brains of living people, thanks to a special kind of imaging.

“I was skeptical,” said Dr. Juan Piantino of Oregon Health & Science University, whose team reported the findings Monday. “We needed this piece to say this happens in humans, too.”

The study was published in the journal Proceedings of the National Academy of Sciences.

The brain is remarkably active during sleep. One reason seems to be that's the time it does a deep clean. And that's gotten attention because while losing a good night’s sleep muddles people’s thinking, chronic sleep deprivation also is considered a risk factor for dementia.

So how does the brain cleanse itself?

Over a decade ago, scientists at the University of Rochester first reported finding a network they dubbed the “glymphatic system." Cerebrospinal fluid uses channels surrounding blood vessels to get deep into tissue and move waste until it exits the brain. When mice were injected with a chief Alzheimer’s culprit named beta-amyloid, it cleared away faster when the animals were sleeping.

It’s not clear exactly how that network works although some research has shown the pulsing of the blood vessels helps move the waste-clearing fluid where it needs go.

But it’s been hard to find that system in people. Regular MRI scans can spot some of those fluid-filled channels but don't show their function, Piantino said.

So his team in Oregon injected a tracer into five patients who were undergoing brain surgery and needed a more advanced form of MRI. The tracer “lit up” under those scans and sure enough, 24 to 48 hours later, it wasn’t moving randomly through the brain but via those channels just like prior research had found in mice.

It’s a small but potentially important study that Rochester’s Dr. Maiken Nedergaard predicted will increase interest in how brain waste clearance connects to people’s health.

But to test if better sleep or other treatments might really spur waste clearance and improve health, “I have to be able to measure glymphatic function in people,” added Dr. Jeff Iliff of the University of Washington, who helped pioneer waste-clearance research. The question is whether the new study might point to ways of measuring.

Sleep isn’t the only question. For example, animal studies show an old blood pressure drug now used to treat PTSD may improve glymphatic function, and Iliff and colleague Dr. Elaine Peskind are about to study it in certain patients.

Additional larger studies in healthy people are needed and Piantino, whose lab focuses on sleep health, wants to find an easier, more noninvasive test.

“We cannot study all these questions by injecting people,” he said.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

https://abcnews.go.com/amp/Health/wireStory/peek-inside-human-brain-shows-cleans-waste-114579188

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Ghost Guns, Trans Surgeries, and P*rn Access: Some of the Major Cases SCOTUS Will Hear This Term.. 1/2

The United States Supreme Court, coming off of possibly its most historic and impactful term in United States history earlier this year, is set to consider a new docket of cases that could have significant impacts when the court issues a new round of rulings next year.While most of the new cases before the high court lack the explosive political nature of —setting major precedent regarding presidential immunity (Trump v. United States), rolling back the Biden-Harris Department of Justice’s aggressive January 6 prosecutions (Fischer v. United States) or undoing decades of federal regulatory procedure (Loper Bright Enterprises v. Raimondo) several cases still carry significant legal and constitutional weight.Before the court in its new term are cases dealing with so-called “ghost guns,” discretionary immigration actions, a Tennessee sex-change ban, and even a lawsuit filed by the Mexican government alleging U.S. gun manufacturers are trafficking firearms to cartels.Additionally, the Court will hear a case on the constitutionality of Texas’s ageverification requirements for pornographic websites. and a case regarding workplace discrimination and whether workers representative of demographic majorities have a higher bar to prove bias.

GHOST GUNS.

One of the most anticipated cases of the term is Garland v. VanDerStok. The case revolves around a 2022 rule issued by the Bureau of Alcohol, Tobacco, Firearms, and Explosives, which would effectively extend licensing and serial number provisions required under the Gun Control Act of 1968 (GCA) to so-called ghost guns—firearms produced at home often through the use of 3D printing.The respondents in the case are challenging the agency’s regulatory authority to unilaterally redefine the definition of “frame or receiver” and “firearm” under the GCA. Garland v. VanDerStok marks the first significant challenge to federal regulatory authority after the Supreme Court struck down much of the long-standing Chevron Deference legal doctrine, which granted federal agencies broad regulatory powers, in its Loper decision earlier this year.

IMMIGRATION VISA APPEALS.

A case that could have major implications for U.S. immigration policy is Bouarfa v. Mayorkas. The high court is being asked to determine whether immigration visa applicants are entitled to legal appeal and judicial review over discretionary application decisions.The case stems from a lawsuit brought by Amina Bouarfa, a U.S. citizen, regarding her attempt to obtain an immigrant visa for her husband, Ala’a Hamayel. In 2014, Bouarfa submitted a Form I-130 seeking to classify Hamayel as her immediate relative under U.S. immigration law. While the petition was initially approved a year later, it was later revoked under the discretionary authority of the Secretary of Homeland Security after it was discovered that Hamayel had previously attempted to evade U.S. immigration laws by entering into a sham marriage.Subsequently, Bouarfa filed suit in a Florida federal District Court challenging the Secretary’s discretionary authority. However, the court dismissed the lawsuit, claiming it had no authority to review a discretionary action by the executive branch. The U.S. Eleventh Circuit later upheld the dismissal.

TRANS SURGERIES FOR MINORS.

In United States v. Skrmetti, the Supreme Court will hear arguments as to whether laws enacted by Tennessee and Kentucky that restrict access to sex-change surgeriesfor minors constitute a violation of the 14th Amendment’s equal protection clause and its incorporation of due process rights. Under the 2023 laws passed by Tennesee and Kentucky, minors are prohibited from receiving puberty blockers, hormone replacement treatments, or sex-change surgeries from healthcare providers operating in either respective state.The plaintiffs in the case contend that both state laws violate 14th Amendment protections and were initially successful in securing injections against the prohibitions from taking effect. However, the injunctions were later lifted by the Sixth Circuit Court of Appeals—meaning the laws have since been allowed to go into effect.

https://thenationalpulse.com/analysis-post/ghost-guns-trans-surgeries-and-prn-access-some-of-the-major-cases-scotus-will-hear-this-term/

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MEXICO SUES GUN MAKERS.

In a case with international repercussions, the court will hear Smith & Wesson Brands v. Estados Unidos Mexicanos. In this case, the government of Mexico is suing U.S. gun manufacturers, alleging the companies have been complicit in trafficking firearms across the southern border to Mexican drug cartels.The question before the court is whether the lawsuit brought by Mexico can proceed under the conditions set out by the Protection of Lawful Commerce in Arms Act (PLCAA). Initially, the lawsuit was halted after a U.S. District Court in Massachusetts found the Mexican government’s legal claims against the gun makers were barred under the PLCAA. However, the First Circuit Court of Appeals reversed the determination on several of Mexico’s claims—citing the PLCAA’s “predicate exception.”Justices will decide whether Mexico’s claims of arms trafficking and injury to its citizens violate U.S. law and trigger the exception to legal protection for the gun manufacturers under the PLCAA.

TEXAS AGE VERIFICATION.

A prominent First Amendment case before the court is Free Speech Coalition, Inc. v. Paxton, which revolves around a Texas law requiring the implementation of age verification procedures for pornographic websites. The court is being asked to determine whether the Texas regulations violate the free speech right of pornographic websites and whether specific provisions run afoul of Section 230 of the Communications Decency Act.An earlier holding by a federal District Court resulted in a preliminary injunction against the Texas law. The District Court determined that Texas’s age verification requirements failed the strict scrutiny test, meaning it was not sufficiently tailored in a narrow scope to achieve the government’s compelling interest. Additionally, the lower court, in issuing the injections, held that the plaintiffs were likely to prevail on First Amendment grounds against Texas upon further appeal.However, the Fifth Circuit Court of Appeals vacated the injunction and reversed the District Court’s holding in part, determining the rational basis review test was more appropriate for the case.

STRAIGHT DISCRIMINATION?

The most peculiar case of the Supreme Court term is Ames v. Ohio Department of Youth Services, which revolves around a reverse discrimination claim. Last Friday, the high court granted certiorari, meaning review, regarding a federal appeals court decision rejecting a reverse discrimination claim brought by a former Ohio Department of Youth Services employee.At the heart of the case is whether reverse discrimination lawsuits brought by those lacking status as a protected class—or demographic majorities—require a higher evidentiary burden. The lawsuit was brought by an Ohio woman who claims she was passed over for a state government job due to her heterosexual orientation.Marlean Ames contends she was denied a promotion by her supervisor, a lesbian woman. Instead, the job went to another lesbian woman, though Ames argues the selected applicant was unqualified. Subsequently, Ames was removed from her position and replaced by a gay man.The plaintiff’s lawsuit was thrown out by a federal court, which found she failed to demonstrate a statistically significant pattern of discrimination against demographic majorities by her employer. The Sixth Circuit Court of Appeals concurred with the lower court decision, resulting in the final appeal to the Supreme Court.Image by Phil Roeder.

https://thenationalpulse.com/analysis-post/ghost-guns-trans-surgeries-and-prn-access-some-of-the-major-cases-scotus-will-hear-this-term/