How Your Brain Cleans Itself - And What Happens When It Goes Wrong

Episode 411 Why may now have an answer as to why autism is less common in women and girls. And it’s all to do with ZFX, a gene that may explain the so-called “female protective effect”. A new study found a set of genes that appear to be linked to autism, all associated with ZFX, which is found on the X chromosome. Because women have two copies of the X, they have twice the expression and activity of the gene than men. While this is promising, it’s not definitive. Underdiagnosis and other genetic factors may be at play. It may not even be true to say autism is four times more common in men than women. To discuss what this new finding means, how our understanding of autism is shifting and whether we should rethink the autism spectrum completely, Rowan Hooper and Penny Sarchet are joined by science writer Michael Marshall. To read more about these stories, visit https://www.newscientist.com/ Join our free, live online event for subscribers on the 18th November: https://www.newscientist.com/science-events/should-we-rethink-the-autism-spectrum/  Image Credits: Emw, CC BY-SA 3.0, via Wikimedia Commons Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 409 COP31 is about to take place against the backdrop of a year of accelerating climate disasters, plus a record breaking October and confirmation that we’ve exceeded the Paris climate agreement. This year's UN climate meeting isn’t planned to be a big one, but will be essential in ironing out a lot of the unresolved agreements made at last year’s meeting in Brazil. But as people continue to question the value of the COP process, can these summits move the needle or do they need major reform? To discuss what we can expect and whether COP is still effective, Rowan Hooper is joined by environment reporter Madeleine Cuff and Mark Maslin, professor of Earth System Science at University College London. To read more about these stories, visit https://www.newscientist.com/ Image Credits:  COP 30: hlcchampions, CC BY 4.0, via Wikimedia Commons COP 21: Guilhem Vellut from Paris, France, CC BY 2.0, via Wikimedia Commons Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 407 The latest UN climate report is out and we’ve blown past 1.5 degrees of warming. We’re now in “overshoot” - an acknowledgement that global temperatures will rise beyond 1.5 degrees, but can theoretically be brought back down again through cooling efforts. But with the world on track fo r2.8 and even as much as 4.5 degrees of warming by 2100, is the challenge of keeping temperatures at a manageable level politically and technologically feasible? As scientists argue whether “overshoot” is failure, conditions at Thwaites glacier in Antarctica are also worsening. The so-called “Doomsday” glacier is melting and an integral ice shelf is on the verge of collapse. Now models show the melting is locked in - and can’t be stopped even if we keep global temperatures down. If it collapses, it could reshape the entire coastline of the world. To discuss the news, Rowan Hooper and Penny Sarchet are joined by Madeleine Cuff and Alison George. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 406 The glymphatic system is the brain’s waste disposal system - responsible for clearing out harmful toxins that build up during the day. Now a new mouse study has connected reduced glyphatic flow to Alzheimer’s disease. And because this glymphatic system cleans the brain during sleep, it’s thought poor sleep may contribute to this reduction in brain function. Rowan Hooper and Penny Sarchet are joined by science writer Michael Marshall, who explains the study in detail, what we know about the effects in humans and the steps we can take to improve our own glymphatic flow. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 405 The Atlantic Meridional Overturning Circulation (AMOC)  is a major system of ocean currents that plays a vital role in Earth’s climate. If it collapses, the consequences could be catastrophic. We could see ice-age level winters in Europe, coupled with scalding hot summers - and impacts on food production around the world. The trouble is it’s already weakening. That’s why scientists are building an early warning system that'll warn us of imminent AMOC collapse. But will a warning come soon enough for us to act - and will anyone actually listen? The team explains how the warning system would work, what happens if the AMOC does collapse and how soon it could happen. Plus they look at new research which suggests the AMOC may not be a classic tipping point - because we may be able to resuscitate it even if it stops. To discuss this, Penny Sarchet and Rowan Hooper are joined by climate reporters Alec Luhn and Madeleine Cuff.  To read more about these stories, visit https://www.newscientist.com/ Image Credit: Tipping Points: CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=148459736 Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 404 Jonathan the tortoise was born in the year 1832, on a beach in the Seychelles. 194 years later and Jonathan is still alive, celebrating his birthday. How exactly has he managed to survive for so long? Jonathan is a giant tortoise and the world’s oldest known land animal. His genome has now been sequenced, revealing intriguing hints about longevity. And it seems the key to a long life is all down to mitochondrial function. From Greenland Sharks to the enigmatic quahog, this also seems to be the case for Earth’s other longest-lived creatures - one of which survived for 507 years.  Rowan Hooper and Penny Sarchet discuss what these animals tell us about the science of healthy aging, whether there are any takeaways for us humans - and they celebrate the amazing life of Jonathan. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 403 A new species of feathered dinosaur has been discovered - and it looks like a supercharged magpie with teeth. Fossil evidence and an artist’s reconstruction show the dinosaur looks remarkably like a bird - yet it’s not actually an ancestor of modern birds. Over 100 million years old, Norellraptor barsboldi is named after two famous palaeontologists - one of whom taught palaeontologist Steve Brusatte. Steve is the author of The Story of Birds and joins the team to discuss this incredible finding, which shows flight may have evolved at least two separate times. He also explains how dinosaurs didn’t go extinct - but still roam among us today. On the panel are Rowan Hooper and Penny Sarchet. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 402 The current El Niño is shaping up to cause catastrophe on a global scale. Global temperatures are being pushed up, unleashing extreme weather which could devastate ecosystems. The heat alone is expected to kill half a million people over the next five months. Sea-surface temperatures are expected to climb 4°C above average in parts of the Pacific - and it’s becoming clear this is an issue that affects us all. From extreme heat in some places to heavy rainfall in others, many countries are bracing for impact. Combined with the threat of “king tides”, California has even declared a state of emergency. Despite the sweltering heat we’ve just experienced, forecasters now say 2027 will be the hottest year on record - before it’s even begun. So how can we prepare? To discuss the threat we’re facing and possible solutions (like geoengineering), Rowan Hooper and Penny Sarchet are joined by climate journalists Madeleine Cuff and Alec Luhn. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 401 Anxiety is everywhere. Climate change, political turmoil and a constant stream of alarming headlines can make optimism feel impossible. But to be hopeful you don’t need to ignore reality. What if it’s about paying attention to the breakthroughs that are already changing the world? In this special episode Penny Sarchet and Rowan Hooper are joined by bestselling author Caitlin Moran, who spent a year chasing hope. Prompted by her new book How to Be Hopeful, the New Scientist team shares eight recent developments that genuinely make them optimistic about the future. From the explosive growth of solar energy and the possibility of crops that make their own fertiliser, to new classes of medicines, AI-assisted scientific discovery, and even the search for life beyond Earth, this episode is a celebration of progress, curiosity and human ingenuity.  Also on the panel are Madeleine Cuff, Catherine de Lange, and Michael Le Page. To read more about these stories, visit https://www.newscientist.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Episode 400 Should we really be afraid of AI? Many headline statements from the likes of Anthrophic, OpenAI and even the King are raising alarm bells over the threat of AI to humanity. AI companies are even calling to be more highly regulated. But does that mean the threats are worth considering - or are there ulterior motives? Among the apocalyptic or disastrous ways it could go wrong, there are genuine issues we should be thinking about today. Alignment is one of those - how closely AI aligns with human values and whether it continues to obey us. And the threat of supercharged cyber attacks is another. But is extinction really on the cards? To discuss the reality of the situation we’re facing, Rowan Hooper and Penny Sarchet are joined by Timothy Revell, Matthew Sparkes and Jacob Aron. To read more about these stories, visit https://www.newscientist.com/ Image credits:  Sam Altman: TechCrunch, CC BY 2.0 https://creativecommons.org/licenses/by/2.0 via Wikimedia Commons Mark Zuckerberg: Anthony Quintano from Honolulu, HI, United States, CC BY 2.0 https://creativecommons.org/licenses/by/2.0 via Wikimedia Commons Learn more about your ad choices. Visit megaphone.fm/adchoices