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Investigating Critical Period Effects in Language Acquisition through Neural Language Models

Ionut Constantinescu, Tiago Pimentel, Ryan Cotterell, Alex Warstadt ETH Zurich 2024 https://arxiv.org/abs/2407.

Children are better at learning a…


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Hydrogen Sulfide and Gut Microbiota: Their Synergistic Role in Modulating Sirtuin Activity and Potential Therapeutic Implications for Neurodegenerative Diseases

The intricate relationship between hydrogen sulfide (H2S), gut microbiota, and sirtuins (SIRTs) can be seen as a paradigm axis in maintaining cellular homeostasis, modulating oxidative stress, and promoting mitochondrial health, which together play a pivotal role in aging and neurodegenerative diseases. H2S, a gasotransmitter synthesized endogenously and by specific gut microbiota, acts as a potent modulator of mitochondrial function and oxidative stress, protecting against cellular damage. Through sulfate-reducing bacteria, gut microbiota influences systemic H2S levels, creating a link between gut health and metabolic processes. Dysbiosis, or an imbalance in microbial populations, can alter H2S production, impair mitochondrial function, increase oxidative stress, and heighten inflammation, all contributing factors in neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

First data emerges from ‘direct-to-brain’ Alzheimer’s stem cell therapy trial

The small-scale FDA-cleared trial is designed to evaluate both the safety and initial efficacy of RB-ADSCs in nine patients with Alzheimer’s. Regeneration Biomedical’s CTAD presentation focused on the first three enrolled patients, who each received a single dose of RB-ADSCs delivered directly into the lateral ventricles of the brain using an “Ommaya reservoir” – a device implanted under the scalp to bypass the blood-brain barrier, a major obstacle in Alzheimer’s treatments.

Biomarker analysis at the 12-week mark demonstrated reductions in both p-Tau and amyloid-beta – two proteins strongly associated with Alzheimer’s disease progression. In cerebrospinal fluid (CSF) samples from the three patients, p-Tau levels decreased to “normal” levels, while amyloid PET scans also showed a reduction in amyloid buildup.

Regeneration Biomedical also reported its treatment produced signs of cognitive improvement, with two of the three patients showing increased Mini-Mental State Examination (MMSE) scores, a common measure of cognitive function.

Your brain is constantly working to “predict” what’s happens next

Ever noticed how you catch a falling glass before it even registers that it’s slipping? That’s because your brain is constantly making predictions, keeping you one step ahead of reality.

As difficult as it may be to believe, our minds don’t just process what’s happening — they anticipate what’s about to happen next.

This intriguing concept comes from researchers Christian Keysers and Valeria Gazzola of the Netherlands Institute for Neuroscience, along with Giorgia Silani from the University of Vienna.

Space-Born Stem Cells: A New Frontier in Regenerative Medicine

Dr. Abba Zubair, MD: “Our hope is to study these space-grown cells to improve treatment for age-related conditions such as stroke, dementia, neurodegenerative diseases and cancer.”


What can microgravity teach us about stem cell growth? This is what a recent study published in NPJ Microgravity hopes to address as a pair of researchers from the Mayo Clinic investigated past research regarding the growth properties of stem cells, specifically regeneration, differentiation, and cell proliferation in microgravity and whether the stem cells can maintain these properties after returning to Earth. This study holds the potential to help researchers better understand how stem cell growth in microgravity can be transitioned into medical applications, including tissue growth for disease modeling.

“The goal of almost all space flight in which stem cells are studied is to enhance growth of large amounts of safe and high-quality clinical-grade stem cells with minimal cell differentiation,” said Dr. Abba Zubair, MD, who is a faculty at the Mayo Clinic and the sole co-author on the study. “Our hope is to study these space-grown cells to improve treatment for age-related conditions such as stroke, dementia, neurodegenerative diseases and cancer.”

For the study, the researchers examined past research that launched stem cell cultures to the International Space Station (ISS) to have astronauts onboard evaluate the stem cells’ growth patterns and behavior under microgravity conditions. Dr. Zunair has launched stem cells to the ISS on three occasions and the various types of stem cells examined on the ISS in previous research include mesenchymal stem cells, hematopoietic stem cells, cardiovascular progenitor stem cells, and neural stem cells.

Physics for excited neurons

“Badass”. That was the word Harvard University neuroscientist Steve Ramirez used in a Tweet to describe research published online by fellow neuroscientist Ali Güler and colleagues in the journal Nature Neuroscience last March. Güler’s group, based at the University of Virginia in the US, reported having altered the behaviour of mice and other animals by using a magnetic field to remotely activate certain neurons in their brains. For Ramirez, the research was an exciting step forward in the emerging field of “magnetogenetics”, which aims to use genetic engineering to render specific regions of the brain sensitive to magnetism – in this case by joining proteins containing iron with others that control the flow of electric current through nerve-cell membranes.

By allowing neurons deep in the brain to be switched on and off quickly and accurately as well as non-invasively, Ramirez says that magnetogenetics could potentially be a boon for our basic understanding of behaviour and might also lead to new ways of treating anxiety and other psychological disorders. Indeed, biologist Kenneth Lohmann of the University of North Carolina in the US says that if the findings of Güler and co-workers are confirmed then magnetogenetics would constitute a “revolutionary new tool in neuroscience”

The word “if” here is important. In a paper posted on the arXiv preprint server in April last year and then published in a slightly revised form in the journal eLife last August, physicist-turned-neuroscientist Markus Meister of the California Institute of Technology laid out a series of what he describes as “back-of-the-envelope” calculations to check the physical basis for the claims made in the research. He did likewise for an earlier magnetogenetics paper published by another group in the US as well as for research by a group of scientists in China positing a solution to the decades-old problem of how animals use the Earth’s magnetic field to navigate – papers that were also published in Nature journals.

Robert Sapolsky: “The Brain, Determinism, and Cultural Implications” | The Great Simplification #88

On this episode, neuroscientist and author Robert Sapolsky joins Nate to discuss the structure of the human brain and its implication on behavior and our ability to change. Dr. Sapolsky also unpacks how the innate quality of a biological organism shaped by evolution and the surrounding environment — meaning all animals, including humans — leads him to believe that there is no such thing as free will, at least how we think about it today. How do our past and present hormone levels, hunger, stress, and more affect the way we make decisions? What implications does this have in a future headed towards lower energy and resource availability? How can our species manage the mismatch of our evolutionary biology with our modern day challenges — and navigate through a ‘determined’ future?

About Robert Sapolsky:

Robert Sapolsky is professor of biology and neurology at Stanford University and a research associate with the Institute of Primate Research at the National Museum of Kenya. Over the past thirty years, he has divided his time between the lab, where he studies how stress hormones can damage the brain, and in East Africa, where he studies the impact of chronic stress on the health of baboons. Sapolsky is author of several books, including Why Zebras Don’t Get Ulcers, A Primate’s Memoir, Behave: The Biology of Humans at Our Best and Worst, and his newest book coming out in October, Determined: Life Without Free Will. He lives with his family in San Francisco.

For Show Notes and More visit: https://www.thegreatsimplification.co

00:00 — Episode highlight.
00:15 — Guest introduction.
03:10 — When did Robert know he wanted to study animal behavior?
04:40 — When was his last research trip?
05:46 — Challenges that come from differences from modern and ancestral environments.
07:20 — Physiology and our emotions.
09:37 — Divide in evolutionary beliefs.
12:13 — Behavioral science and religion.
14:40 — Past students’ impacted by Robert.
16:48 — Testosterone.
21:07 — Dopamine.
29:02 — Oxytocin.
32:19 — Hormones affecting social behavior.
38:21 — Changing the environmental stimuli of pregnant people to positively impact fetus’ development.
41:55 — Free will.
57:24 — Science of attractiveness.
58:55 — Do people have free will?
1:13:12 — Emergence.
1:18:17 — Quantum and indeterminacy.
1:19:18 — Complexity of free will.
1:23:46 — Difference between free will and agency.
1:26:43 — How to use Robert’s work to change policies around the world in a positive way.
1:29:15 — What’s the difference between a deterministic world and a fatalistic one?
1:34:39 — Robert’s thoughts on his newest book, Determined: Life Without Free Will.
1:40:48 — Key components in a new systems society understanding this science.
1:45:30 — What should listeners take away from this podcast?
1:47:32 — Robert’s recommendations for the polycrisis.
1:52:20 — What Robert cares most about in the world.
1:53:00 — Robert’s magic wand.
1:54:36 — Future topics of conversations.

#natehagens #thegreatsimplification #neuroscience #dopamine #freewill #testosterone

Is There Free Will? The Unsettling Science Behind Our Everyday Decisions | Dr. Robert Sapolsky

In a world where choices seem endless, could it be that our ‘free will’ is nothing more than an illusion?

When it comes to things like choosing a morning run over an extra hour of sleep, opting for an apple instead of that enticing pint of ice cream, or quitting your job on a whim…

…What’s truly guiding these decisions? Is it willpower, biology, environment, or perhaps a unique strength of character we’ve built over time?

Or… could it be something else entirely, something beyond our control?

Here’s where our guest, Dr. Robert Sapolsky — a renowned Professor of Biology, Neurology and Neurosurgery at Stanford University — offers us a slightly unsettling, yet eye-opening, perspective.

He suggests that every decision we make — from the podcasts we tune into, to judges making a case verdict, to choosing our life partner — isn’t shaped by any sort of conscious control or free will. Instead, he believes our actions are driven by factors beyond our grasp and influence.

China: Liver helps revive dead pig’s brain after 50 mins of no oxygen

Scientists in China have managed to revive brain activity in pigs nearly an hour after circulation ceased, thanks to the surprising involvement of the liver.

If translatable to humans, this finding could have significant implications for extending the critical window in which doctors can resuscitate patients following sudden cardiac arrest.

The research team, led by Dr. Xiaoshun He at Sun Yat-Sen University, experimented with the brains of 17 Tibetan minipigs to investigate how the liver might influence brain recovery.