BBB Cells - Pain Puzzles - Body Awareness - Biorhythms & Hair

[Breedlove, S]

https://www.thetransmitter.org/choroid-plexus/newly-identified-barrier-cells-seal-off-choroid-plexus-from-csf-rest-of-brain/

Newly identified barrier cells seal off choroid plexus from CSF, rest of brain

By Claudia López Lloreda

A previously unrecognized population of fibroblasts seals off the base of the choroid plexus—the network of blood vessels and cerebrospinal-fluid-producing epithelial cells that line the ventricles—from the cerebrospinal fluid (CSF) and the rest of the brain, a new study in mice shows. 

The newly identified barrier provides an added layer of protection that is distinct from the well-known blood-brain barrier and the one that the epithelial cells form between the blood and the CSF. 

The findings help settle a long-standing debate about whether there was a blind spot in the choroid plexus that gave the periphery access into the brain, says Britta Engelhardt, professor of immunobiology at the University of Bern, who was not involved in the work. “Some [scientists] speculated that there is a leak, like an opening, a secret window into the brain, and others said, ‘No, there must be a barrier that we have overlooked.’ And it’s very obvious now.” 

Fibroblasts at the base of the choroid plexus, connected by adherens and tight junction proteins, cluster together around blood vessels and form a sealed barrier in mice, the researchers found. This structure represents a crucial component of compartmentalization in the choroid plexus, Engelhardt says. The cells were also present in human postmortem brain samples. 

Similar to other barriers, the seal becomes leaky in response to inflammation triggered by lipopolysaccharide, a component of the bacterial cell wall, and it may coordinate immune cell crossing from the blood into the brain, the study also showed. The work was published in February in Nature Neuroscience.

© 2026 Simons Foundation

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https://www.npr.org/2026/04/04/nx-s1-5699477/pain-science-sanjay-gupta

 Dr. Sanjay Gupta explains what we do — and still don't — know about pain

Marielle Segarra

When neurosurgeon and journalist Dr. Sanjay Gupta set out to write a book about pain, it wasn't because he felt like he had all the answers. It was because he was still so often mystified by it.

"Most of my patients come to me for pain. Head pain, back pain, neck pain, whatever it might be," he says. "If that's what the majority of your professional life is, you should understand it as best you can."

His 2025 book, It Doesn't Have to Hurt: Your Smart Guide to a Pain-Free Life, gathers the latest developments in pain science, based on his own experience with patients and conversations with researchers and doctors.

What he found may challenge your own understanding of pain and even give you the tools to help you feel better. There's evidence, for example, that just learning about pain and how it works "seems to be pain relieving" for those with chronic pain conditions, he says.

Gupta, who also serves as the chief medical correspondent for CNN, explains what we still don't know about pain and shares a few effective new treatments. This interview has been edited for length and clarity.

In your book, you say that one of the most significant developments emerging in pain treatment is the fact that the brain is at the center of any pain experience. Can you tell us more about why that matters?

What I think has become clear — and I'm not the first person to say this — is the idea that if the brain doesn't decide you have pain, then you don't have pain.

   © 2026 npr


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https://www.sciencenews.org/article/mind-wander-body-mental-health

When our minds wander to the body, it may affect mental health

By Diana Kwon

Human minds often wander. Whether we’re busy at work, doing chores or exercising, our thoughts frequently shift away from the task at hand. These spontaneous thoughts sometimes turn toward sensations in the body, such as our heartbeat or breath, and that could affect our immediate emotional state and long-term mental health, researchers report March 25 in Proceedings of the National Academy of Sciences.

Many studies focus on thinking about memories, events and other people, what scientists consider the cognitive aspects of mind wandering, says Micah Allen, a neuroscientist at Aarhus University in Denmark. This research suggests that mind wandering plays an important role in planning, learning, creativity and other important mental processes. It has also been linked to negative emotions and some, such as obsessively ruminating on past mistakes, may contribute to depression, attention-deficit/hyperactivity disorder and other mental illnesses.
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But how the mind might drift to bodily sensations, what some researchers call “body wandering,” and its effects have largely been overlooked, Allen says. 

He and colleagues had 536 people lie still in a magnetic resonance imaging scanner and then complete a questionnaire about what was on their minds during that time. In addition to the typical content of daydreams, such as memories, plans or social interactions, participants reported paying attention to sensations in their body, such as their breathing, heartbeats and bladder. The team also found evidence of this in the MRI scans: Body wandering appeared to have a distinct brain signature from that of “cognitive” mind wandering.

© Society for Science & the Public 2000–2026. 
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https://nautil.us/your-biological-clock-can-be-measured-with-a-hair-sample-1279506

Your Biological Clock Can be Measured With a Hair Sample

By Jake Currie

Ever wonder why jet lag is such a horribly uncomfortable experience? It’s because your biological clock doesn’t just regulate your sleep cycle, it affects a whole host of other bodily functions, like hormone levels, metabolism, your immune activity, and more. 

That means when your circadian rhythms get disrupted, it can throw a wrench into a variety of systems. It also means that time of day can be an important factor when considering medical treatments. For example, aortic valve replacements performed in the afternoon are associated with fewer adverse side effects. 

Unfortunately determining what “time” your internal clock reads is a little more difficult than glancing at a watch, in part because everyone’s biological clock ticks at a slightly different pace. Right now, the single most accurate test involves repeatedly measuring the levels of melatonin in the saliva during the hours leading up to bedtime, which is difficult to do outside of a laboratory or hospital environment. 

Now, according to new research published in the Proceedings of the National Academy of Sciences, chronobiologists have developed a way to get an accurate read of your biological clock from a simple hair sample. By measuring the transcriptional activity of clock genes in hair follicle cells and performing an analysis using artificial intelligence, they’ve been able to accurately pinpoint the biological clock’s time.

“In these cells, we measure the activity of 17 genes that are part of the molecular clock or are controlled by it,” study author Achim Kramer of Charité—Universitätsmedizin Berlin explained in a statement. “Using machine learning, this pattern can be used to calculate at what point in the daily rhythm the person is currently at. A single sample is sufficient for this.” 
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