After 20 months, scientists find lab-dish brain cells matured at a similar rate to those of an actual infant.
- Scientists have found that cultures of embryonic brain cells mature at the same rate as a 20-month-old infant's.
- Researchers have looked to such cell structures, called "organoids," as potential models for understanding the human body's biological mechanisms.
- Their study validates the use of lab-dish organoids for research.
What organoids really are and aren't<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY4MzgzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1OTEzMjc5Mn0.R1KWf66xU7CYlT3CPthA2J-xJKjZP0h0W4vx2Quxiq8/img.jpg?width=980" id="60c18" class="rm-shortcode" data-rm-shortcode-id="a496d5eb7684457c09d0139882876a8f" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="1080" />
A brain organoid
Credit: NIH Image Gallery/Wikimedia<p>Organoids are tissue cultures comprised of human embryonic stem cells. They start off as induced pluripotent stem cells (IPS) drawn from skin cells or blood cells before being reprogrammed to revert to an embryonic stem-cell-like state. From there, they can be exposed to chemicals that cause them to behave like a specific type of human cell.</p><p>In the case of this study, the chemicals caused them to become cerebral organoids, self-organized 3D cell structures that behave similarly to natural human brain cells. They don't grow to become full mini-brains.</p>
The promise of organoids<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY4Mzg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMDEzODg0Nn0.AmSwbhi7wxpv1vKOX4jqOhB-pEqJNyFQzu2mhzHWTvc/img.jpg?width=980" id="92a7b" class="rm-shortcode" data-rm-shortcode-id="3746da47064a9d07ca33ddf44c5c1880" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: David Matos/Unsplash<p>The hope for organoids has been that they would provide researchers a way of observing human biological process in a benign, non-invasive way. Insights regarding the manner in which human cells and organs develop a disease, progress through its stages, and respond, or not, to medication, without involving actual human subjects or animal analogues could revolutionize research.</p><p>In the case of brain organoids, researchers have been hoping they can somehow be used to reveal the secrets of neurological and neurodevelopmental disorders, including epilepsy, autism and schizophrenia.</p><p>That organoids <em>could</em> be useful—though that doesn't mean that they <em>would</em> be—as a result of their permanently remaining embryonic cells. This study is a first indicator that organoids' larger promise can actually be fulfilled. </p>
An answer scientists have been hoping for<p>"This is novel," says Geschwind. "Until now, nobody has grown and characterized these organoids for this amount of time, nor shown they will recapitulate human brain development in a laboratory environment for the most part."</p><p>Now, says first author <a href="https://geschwindlab.dgsom.ucla.edu/pages/aaron-gordon" target="_blank">Aaron Gordon</a>, "We show that these 3D brain organoids follow an internal clock, which progresses in a laboratory environment in parallel to what occurs inside a living organism. This is a remarkable finding — we show that they reach post-natal maturity around 280 days in culture, and after that begin to model aspects of the infant brain, including known physiological changes in neurotransmitter signaling."</p><p>With the study verifying a 20-month maturation process, it remains to be seen how long, or how far, maturation in organoids goes. Can their cells continue to mature for years? Decades?</p><p>Even without an answer to that question, the study, says Geschwind, "represents an important milestone by showing which aspects of human brain development are modeled with the highest fidelity and which specific genes are behaving well in vitro and when best to model them. Equally important, we provide a framework based on unbiased genomic analyses for assessing how well in vitro models model in vivo development and function."</p><p>With IPS cells able to take on the roles of so many types of cells in the human body, and the new knowledge that they do in fact mature beyond their embryonic stage, researchers can feel more confident of insights into biological mechanisms organoids seem to reveal. And researchers can now better equipped to solve some of the human body's vexing mysteries.</p>
New studies show that some people can hear and respond to questions while dreaming.
- Four research teams in four countries independently communicated with sleeping volunteers.
- A total of 36 participants correctly responded to questions 18.6% of the time.
- Researchers believe this could open up new avenues for treating anxiety, depression, and trauma.
Dream Hacking: Watch 3 Groundbreaking Experiments on Decisions, Addictions, and Sleep I NOVA I PBS<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="77f2961e9a759ae62924a8efd37a61f0"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/7M06fJxiayo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Participants in this study certainly experienced their imagination stretching, with one volunteer "hearing" the math problem (what is eight minus six?) through a car radio while another dreamer was questioned by a movie narrator.</p><p>The results were not overwhelmingly positive mind you, yet still proved successful enough to warrant further research. One researcher called this "<a href="https://www.sciencemag.org/news/2021/02/scientists-entered-peoples-dreams-and-got-them-talking" target="_blank">proof of concept</a>" more than total confirmation. Over 60 percent of the questions went unanswered. Another 17.7 percent were unclear, while just over 3 percent answered wrong. Yet 18.6 percent of respondents were on the money, an impressive feat for the sleeping. </p><p>While the researchers aren't stealing secrets from the subconscious, they hope this discovery could open up new avenues of therapeutics in the treatment of anxiety, depression, and trauma. The idea of accessing "dream content" that they can inform with new content could lead to non-invasive forms of treatment—or "Inception."</p><p>As the team writes, </p><p style="margin-left: 20px;">"The scientific investigation of dreaming, and of sleep more generally, could be beneficially explored using interactive dreaming. Specific cognitive and perceptual tasks could be assigned with instructions presented via softly spoken words, opening up a new frontier of research."</p><p>Of course, more research is needed, though volunteers will likely not be hard to find. Peeling back the layers of consciousness is both a philosophical pursuit and a nighttime hobby, one that continues to reveal possibilities as we evolve our understanding of the unconscious. </p><p> --</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a> and <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a>. His most recent book is</em> "<em><a href="https://www.amazon.com/gp/product/B08KRVMP2M?pf_rd_r=MDJW43337675SZ0X00FH&pf_rd_p=edaba0ee-c2fe-4124-9f5d-b31d6b1bfbee" target="_blank" rel="noopener noreferrer">Hero's Dose: The Case For Psychedelics in Ritual and Therapy</a>."</em></p>
From baboon hierarchies to the mind-gut connection, the path to defeating depression starts with understanding its causes.
- According to the World Health Organization, more than 264 million people suffer from depression. It is the leading cause of disability and, at its worst, can lead to suicide. Unfortunately, depression is often misunderstood or ignored until it is too late.
- Psychologist Daniel Goleman, comedian Pete Holmes, neuroscientist Emeran Mayer, psychiatrist Drew Ramsey, and more outline several of the social, chemical, and neurological factors that may contribute to the complex disorder and explain why there is not a singular solution or universal "cure" that can alleviate the symptoms.
- From gaining insight into how the brain-gut connection works and adopting a more Mediterranean diet, to seeking help from medical or spiritual practitioners, depression is a personal battle that requires a personalized strategy to keep it at bay, as well as more research and understanding.
Scientists observe how the halves of the brain keep us informed about everything everywhere.
Two sides of the big picture<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTYyOTU1OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2NjE3NjE3MX0.q8bjy5ldUXkOb4yzM1jDnegFzSuPpbIHwf5_tHwmtIc/img.jpg?width=980" id="58536" class="rm-shortcode" data-rm-shortcode-id="de188da2682b8c9bb2aff8da3baae4b0" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="972" />
Credit: Jake Schumacher/Unsplash<p>In our working memories, the left and right hemispheres work independently when it comes to memory storage — what we see on our left is immediately stored in the right hemisphere and vice versa.</p><p>The Picower researchers have found, however, that things get substantially more interesting when we shift our gaze in the opposite direction, or if an object we're looking at moves from one side to the other.</p><p>Using our street-crossing example, when you look to the right and spot the approaching vehicle, a memory of the car is stored in our brain's left hemisphere. When you look left, a copy of that memory is quickly sent to the right hemisphere, but the copy is somehow marked in such a way that the brain understands it's not actually located on your left but is just a memory of something that's currently out of view on your right. The net result is that your working memory remains aware of traffic on both sides even when it's just looking in one direction.</p><p>"If you didn't have that," says <a href="https://picower.mit.edu/earl-k-miller" target="_blank">Earl Miller</a>, senior author of the study and in whose lab the research was conducted, "we would just be simple creatures who could only react to whatever is coming right at us in the environment, that's all. But because we can hold things in mind, we can have volitional control over what we do. We don't have to react to something now, we can save it for later."</p>
Games animals play<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTYyOTU2Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MTA4NDMwOH0.7_nXD1yRN3-MJouaRikNw54Y1MIn5j1VOYenA_GhcfE/img.jpg?width=980" id="3a8e3" class="rm-shortcode" data-rm-shortcode-id="af207311aeca3e4ad9c47bbe23092006" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="1077" />
Credit: Eric Isselée/Adobe Stock<p>For the study's experiments, monkeys were taught to identify onscreen objects that didn't match something they had viewed moments earlier, such as an image of a banana. To do this, they had to hold a memory of the original object in memory to make the comparison.</p><p>As this happened, researchers monitored the electrical activity of hundreds of neurons in the prefrontal cortices of both hemispheres. The researchers observed memory transfers as they happened thanks to characteristic patterns in the synchronization of brainwave frequencies that occurred each time a memory was stored, an action that takes mere milliseconds. A software decoder identified the telltale patterns.</p><p>The trials began with the monkeys staring at one side of the screen as an object appeared in the screen's center. As the monkeys perceived the object as belonging primarily to one side or the other, the researchers saw the original memory being stored in the corresponding hemisphere and a copy being made in the other.</p><p>Monkeys were also instructed at times to look from one side to the other, reassigning the central object to a new primary side as the researchers observed the memories being re-written. The speed with which monkeys could spot non-matching objects slowed down during these shifts, giving some hint of the complicated memory gymnastics going on. "It feels trivial to us, but it apparently isn't," says Miller.</p>
An ensemble surprise and mystery<p>The memory is transferred from a group, or ensemble, of neurons in one hemisphere to another ensemble on the other side. One of the surprises in the study is that even though the original memory and its copy describe the same object in the same location, they use completely different neuron ensembles on each side to represent it.</p><p>Miller notes that it used to be believed that individual neurons stored memories but that over time it became clear that groups, or ensembles, of neurons were the actual memory receptacles. Now however, if the same memory is stored in two different types of ensembles due to a difference in their role within a particular hemisphere, maybe things are even more complex than that. "Perhaps even ensembles aren't the functional units of the brain," he surmises. "So what is the functional unit of the brain? It's the computational space that brain network activity creates."</p>
How much of this can be linked to genetics?
- A study on more than 12,000 test subjects finds that risk aversion is related to how much gray matter people have in their brains.
- A follow up on another 13,000 test subjects further supports the findings.
- The study is not the last word on the nature versus nurture question.