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Our memory comes from an ancient virus, neuroscientists say
This study is radically changing how we view the process of evolution.
The particulars surrounding how our memory works has baffled neuroscientists for decades. Turns out, it’s a very sophisticated process involving several brain systems. What about on the molecular level? Inside the brain, proteins don’t stick around longer than a few minutes. And yet, our memories can hang on for our entire lifetime.
Recently, an international collaboration of researchers from the University of Utah, the University of Copenhagen, and the MRC Laboratory of Molecular Biology in the UK, discovered something strange about a protein called Arc. This is essential to long-term memory formation. What they found was that it has very similar properties to how a virus infects its host. Their findings were published in the journal Cell.
In it researchers write, “The neuronal gene Arc is essential for long-lasting information storage in the mammalian brain, mediates various forms of synaptic plasticity, and has been implicated in neurodevelopmental disorders.” They go on to say, “little is known about Arc’s molecular function and evolutionary origins.”
As a result of the study, researchers now believe that a chance encounter occurring hundreds of millions of years ago, led to Arc’s centrality in our memory function today. Assistant professor of neurobiology Jason Shepherd, Ph.D. of the University of Utah, led this research project. He’s dedicated himself to the study of the protein for the last 15 years.
A protein in our memory behaves like a virus. Pictured: the Simian virus 40. Credit: Phoebus87, Wikimedia Commons.
“At the time, we didn’t know much about the molecular function or evolutionary history of Arc,” Dr. Shepherd said in a press release. “I had almost lost interest in the protein, to be honest. After seeing the capsids, we knew we were onto something interesting.” Using electro-microscopy, Shepherd and colleagues studied the protein closely. They realized from an image they’d taken, that the way that Arc assembles itself looks a lot like how the HIV retrovirus operates.
Researchers were intrigued by the idea that a protein could behave like a virus and serve as the platform through which neurons communicate. What Arc does is open a window through which memories can become solidified. Without Arc, the window cannot be opened.
Previous work had shown that Arc is required for long-term memory formation. In one study, mice lacking Arc had little plasticity in their brains and couldn’t recall what happened to them, just 24 hours before. But no one suggested a mechanism mimicking a foreign entity at work, until now.
Shepherd and colleagues now believe that 350-400 million years ago, the ancestor to the retrovirus, the retrotransposon, injected its genetic material into a land-based, four-limbed creature. This led to the development of the Arc protein, as it operates in our neurochemistry today. According to a recent University of Massachusetts study, the same process developed in fruit fries, independently, sometime later, around 150 million years ago.
An HIV capsid. Credit: Thomas Splettstoesser, Wikimedia Commons.
Shepherd and colleagues found that Arc acts like a viral capsid. Capsids are a hard, outer shell which are hollow inside and carry a virus’s genetic information. A virus uses the capsid to spread its genetic material from one cell to another, causing an infection.
How Arc mimics this is, it encapsulates its RNA in order to transfer it from one neuron to another. Elissa Pastuzyn, Ph.D. is a postdoctoral fellow and the lead author of this study. She said in a press release, “We went into this line of research knowing that Arc was special in many ways, but when we discovered that Arc was able to mediate cell-to-cell transport of RNA, we were floored.” She added, “No other non-viral protein that we know of acts in this way.”
The study is changing how we view the evolutionary process. Rather than random mutations, it suggests that organisms may borrow from one another in order to develop. To test the theory, Shepherd and colleagues devised a number of experiments to see whether or not Arc operates like a virus.
What they found was, the protein replicates several copies of itself in capsids, which carry its mRNA inside. They then took these capsids and placed them into petri dishes containing mouse neurons, where they observed Arc transferring its mRNA from one to the next. It appears that activating a neuron triggers more Arc, which causes the release of more capsids, and so a domino effect occurs.
To learn more about this study, click here:
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Construction of the $500 billion dollar tech city-state of the future is moving ahead.
- The futuristic megacity Neom is being built in Saudi Arabia.
- The city will be fully automated, leading in health, education and quality of life.
- It will feature an artificial moon, cloud seeding, robotic gladiators and flying taxis.
The Red Sea area where Neom will be built:
Saudi Arabia Plans Futuristic City, "Neom" (Full Promotional Video)<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="c646d528d230c1bf66c75422bc4ccf6f"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/N53DzL3_BHA?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Frequent shopping for single items adds to our carbon footprint.
- A new study shows e-commerce sites like Amazon leave larger greenhouse gas footprints than retail stores.
- Ordering online from retail stores has an even smaller footprint than going to the store yourself.
- Greening efforts by major e-commerce sites won't curb wasteful consumer habits. Consolidating online orders can make a difference.
A pile of recycled cardboard sits on the ground at Recology's Recycle Central on January 4, 2018 in San Francisco, California.
Photo by Justin Sullivan/Getty Images<p>A large part of the reason is speed. In a competitive market, pure players use the equation, <em>speed + convenience</em>, to drive adoption. This is especially relevant to the "last mile" GHG footprint: the distance between the distribution center and the consumer.</p><p>Interestingly, the smallest GHG footprint occurs when you order directly from a physical store—even smaller than going there yourself. Pure players, such as Amazon, are the greatest offenders. Variables like geographic location matter; the team looked at shopping in the UK, the US, China, and the Netherlands. </p><p>Sadegh Shahmohammadi, a PhD student at the Netherlands' Radboud University and corresponding author of the paper, <a href="https://www.cnn.com/2020/02/26/tech/greenhouse-gas-emissions-retail/index.html" target="_blank">says</a> the above "pattern holds true in countries where people mostly drive. It really depends on the country and consumer behavior there."</p><p>The researchers write that this year-and-a-half long study pushes back on previous research that claims online shopping to be better in terms of GHG footprints.</p><p style="margin-left: 20px;">"They have, however, compared the GHG emissions per shopping event and did not consider the link between the retail channels and the basket size, which leads to a different conclusion than that of the current study."</p><p>Online retail is where convenience trumps environment: people tend to order one item at a time when shopping on pure player sites, whereas they stock up on multiple items when visiting a store. Consumers will sometimes order a number of separate items over the course of a week rather than making one trip to purchase everything they need. </p><p>While greening efforts by online retailers are important, until a shift in consumer attitude changes, the current carbon footprint will be a hard obstacle to overcome. Amazon is trying to have it both ways—carbon-free and convenience addicted—and the math isn't adding up. If you need to order things, do it online, but try to consolidate your purchases as much as possible.</p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
Building a personal connection with students can counteract some negative side effects of remote learning.
- Not being able to engage with students in-person due to the pandemic has presented several new challenges for educators, both technical and social. Digital tools have changed the way we all think about learning, but George Couros argues that more needs to be done to make up for what has been lost during "emergency remote teaching."
- One interesting way he has seen to bridge that gap and strengthen teacher-student and student-student relationships is through an event called Identity Day. Giving students the opportunity to share something they are passionate about makes them feel more connected and gets them involved in their education.
- "My hope is that we take these skills and these abilities we're developing through this process and we actually become so much better for our kids when we get back to our face-to-face setting," Couros says. He adds that while no one can predict the future, we can all do our part to adapt to it.
Chronic irregular sleep in children was associated with psychotic experiences in adolescence, according to a recent study out of the University of Birmingham's School of Psychology.