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Study: Autistic brains develop differently before birth
New research shows that neurons in autistic brains begin to developmentally diverge in early prenatal stages.
- Autism is known to emerge during prenatal development, but it can't be diagnosed until a child is at least 12 months old.
- A new study observed the differences between autistic and control nerve cells as they grew in vitro.
- Researchers found that developmental divergence in autistic neurons occurs early in prenatal neurodevelopment.
Researchers have long known that autism spectrum conditions emerge early during prenatal neurodevelopment. Less well understood is how autistic nerve cells deviate from other neurons or what triggers this divergence. And because the signs of autism can't be reliably diagnosed until 12 months, at the earliest, this gap between development and diagnosis has led to wild speculation as to the causes of autism among the general public.
Anti-vaxxers continue to spread disinformation on social media despite no evidence linking vaccines to autism. Culpability has been placed on an array of environmental factors, from mercury to contaminated water, processed foods to excessive TV time. None of which is great, but also none of which has been conclusively linked to autism. Then there is the untold number of parents suffering needlessly because someone blamed them for having a "refrigerator"-style of parenting.
To shorten this knowledge gap, researchers at King's College London and Cambridge University set about to determine how nerve cells develop in an autistic brain. Of course, they couldn't perform their study on pregnant women. Such a violation wouldn't reach the docket of any ethics committee, nor is there a means to determine autism before birth. So, they devised an experiment that allowed them to observe developing nerve cells in vitro.
Watching young neurons grow
A side-by-side comparison of neural rosette formation in developing autistic and control neurons.
For the experiment, the researchers selected fifteen individuals, six controls and nine people with an autism spectrum condition but from unique genetic backgrounds. They acquired hair samples from each to extract induced pluripotent stem cells (iPSCs). Pluripotent stem cells are cells that can become any cell of the three primary adult cell groups—hence the name, pluri- as in "many" and -potent as in "potential." These cells can also self-renew and continue to make more copies of themselves.
When a scientist induces a stem cell, they take that cell from its freshman potential and direct it toward senior specialization. In this case, the researchers took the iPSCs and used growth factors to drive them to become nerve cells. They obtained two neural lineages from each individual—one lineage grew into neurons like those from the cortex and the other from the midbrain. Because these iPSCs maintain their owners' genetic material, they grew along the same neurodevelopmental pathway in vitro that they would have in utero.
"Using iPSCs from hair samples is the most ethical way to study early brain development in autistic people. It bypasses the need for animal research, it is non-invasive and it simply requires a single hair or skin sample from a person," Dwaipayan Adhya, the study's first author and a molecular biologist at the Autism Research Centre in Cambridge, said in a release.
The researchers examined the cells at three distinct developmental stages: days 9, 21, and 35. They inspected cellular appearance and also sequenced RNA. They found that the autistic neurons took a very different developmental path than those from the controls.
At day 9, the control neurons cultivated standard neural rosettes, neural-tube-like structures that play a key role in determining cortical neurogenesis. Conversely, the autistic neurons formed smaller or no rosettes and expressed lower levels of key developmental genes. At days 21 and 35, the cellular phenotypes between the autistic and control samples showed even differentiation. The autistic iPSCs, for example, showed an increased rate of cellular identity acquisition but were slower in genetic expression.
Such differences, however, were only seen in the cortical neurons. The midbrain lineages showed little difference between autistic and control samples. Importantly, unlike the cortex, midbrain regions are not known to be associated with autism conditions.
Their evidence strongly suggests that the developmental differences in autistic brains occur early in prenatal neurodevelopment—long before excessive TV time or refrigerator parenting can come into play. The study was published this June in Biological Psychiatry.
Not for a cure but acuity
Could this research lead to a cure for autism? No, and that's not its purpose. In fact, the very wording of that question is misleading as autism isn't a disease. Autistic people aren't sick. Their brains have simply developed uniquely, leading them to think and see the world through a mental lens that is their own.
As Simon Baron-Cohen, study co-lead and director of Autism Research Centre at Cambridge, said in the same release: "Some people may be worried that basic research into differences in the autistic and typical brain prenatally may be intended to 'prevent,' 'eradicate,' or 'cure' autism. This is not our motivation, and we are outspoken in our values in standing up against eugenics and in valuing neurodiversity. Such studies will lead to a better understanding of brain development in both autistic and typical individuals."
Future studies in this area may lead to improved diagnostic techniques. This may help families find the resources and support they need to put kids on the path to a healthy, happy life earlier. And the more we know, the more knowledge we have at our disposal to counter disinformation, limiting the spread of the fears and misunderstandings that surrounds autism and other neurodevelopmental conditions.
- Genetic Clues to Autism's Origin - Big Think ›
- Is 'Curing' Autism Offensive? Neurodiversity Movements Reframe ... ›
- The Surprising Symmetry of Brains on the Autism Spectrum - Big Think ›
- Neurodiversity definition: common misconceptions cleared up - Big Think ›
- Autism brain: how the autistic brain develops differently - Big Think ›
- How the autistic brain develops differently - Big Think ›
What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
Scientists find that bursts of gamma rays may exceed the speed of light and cause time-reversibility.
- Astrophysicists propose that gamma-ray bursts may exceed the speed of light.
- The superluminal jets may also be responsible for time-reversibility.
- The finding doesn't go against Einstein's theory because this effect happens in the jet medium not a vacuum.
Jet bursting out of a blazar. Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope.
Cosmic death beams: Understanding gamma ray bursts<div class="rm-shortcode" data-media_id="cu2knVEk" data-player_id="FvQKszTI" data-rm-shortcode-id="c6cfd20fdf31c82cb206ade8ce21ba3f"> <div id="botr_cu2knVEk_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/cu2knVEk-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/cu2knVEk-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/cu2knVEk-FvQKszTI.js"></script> </div>
Researchers dramatically improve the accuracy of a number that connects fundamental forces.
- A team of physicists carried out experiments to determine the precise value of the fine-structure constant.
- This pure number describes the strength of the electromagnetic forces between elementary particles.
- The scientists improved the accuracy of this measurement by 2.5 times.
The process for measuring the fine-structure constant involved a beam of light from a laser that caused an atom to recoil. The red and blue colors indicate the light wave's peaks and troughs, respectively.
Scientists at Washington University are patenting a new electrolyzer designed for frigid Martian water.
- Mars explorers will need more oxygen and hydrogen than they can carry to the Red Planet.
- Martian water may be able to provide these elements, but it is extremely salty water.
- The new method can pull oxygen and hydrogen for breathing and fuel from Martian brine.