Cookies help us run our site more efficiently.

By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. View our Privacy Policy for more information or to customize your cookie preferences.

Accept Deny

GoGreenNation news

Unveiling the Molecular Mechanisms Behind PTSD and Depression: Latest Findings

News Feed
Tuesday, June 11, 2024

Researchers from McLean Hospital and collaborating institutions have discovered shared and distinct molecular changes in brain regions, genomic layers, cell types, and blood of individuals with PTSD and MDD, offering new insights for therapeutic and diagnostic advancements. Credit: SciTechDailyStudy reveals molecular distinctions and similarities in PTSD and depression, highlighting potential therapeutic targets and biomarkers.A comprehensive examination of multiple biological processes is essential for understanding the development of stress-related disorders. Recent research conducted by scientists at McLean Hospital, along with collaborators from The University of Texas at Austin and Lieber Institute for Brain Development, has revealed both shared and unique molecular changes in brain regions, genomic layers, cell types, and blood among individuals with posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). These findings, published in Science, could pave the way for innovative treatments and biomarkers.The Complexity of PTSD Explored“PTSD is a complex pathological condition. We had to extract information across multiple brain regions and molecular processes to capture the biological networks at play,” explained lead author Nikolaos P. Daskalakis, MD, PhD. Stress-related disorders develop over time, stemming from epigenetic modifications caused by the interplay between genetic susceptibility and traumatic stress exposure. Although previous research has identified factors such as hormonal, immune, methylomic, and transcriptomic influences, the limited availability of postmortem brain tissues from PTSD patients has hindered a comprehensive understanding of these brain-based molecular changes.Multi-omics Approach to Studying PTSD and Depression“Our primary goals for this study were to interpret and integrate differential gene and protein expression, epigenetic alterations and pathway activity across our postmortem brain cohorts in PTSD, depression and neurotypical controls,” said senior author Kerry Ressler, MD, PhD, chief scientific officer and director of Division of Depression and Anxiety Disorders and Neurobiology of Fear Laboratory at McLean Hospital, and a professor of psychiatry at Harvard Medical School. “We essentially combined circuit biology with powerful multi-omics tools to delve into the molecular pathology behind these disorders.”For this, the team analyzed multi-omic data from 231 PTSD, MDD, and neurotypical control subjects, along with 114 individuals from replication cohorts for differences in three brain regions — the medial prefrontal cortex (mPFC), hippocampal dentate gyrus (DG) and central nucleus of the amygdala (CeA). They also performed single-nucleus RNA sequencing (snRNA-seq) of 118 PFC samples to study cell-type-specific patterns and evaluated blood-based proteins in more than 50,000 UK Biobank participants to isolate key biomarkers associated with stress-related disorders. Finally, the overlap of these key brain-based disease process genes was compared with genome-wide association studies (GWAS)-based risk genes to identify PTSD and MDD risk.Molecular Variations and Disease MechanismsIndividuals with PTSD and MDD shared altered gene expression and exons in the mPFC but differed in the localization of epigenetic changes. Further analysis revealed that a history of childhood trauma and suicide were strong drivers of molecular variations in both disorders. The authors noted that MDD disease signals were more strongly associated with male-specific results, suggesting that sex differences may underlie disease risk.Top disease-associated genes and pathways across regions, omics, and/or traits implicated biological processes in both neuronal and non-neuronal cells. These included molecular regulators and transcription factors, and pathways involved in immune function, metabolism, mitochondria function, and stress hormone signaling.Implications for Diagnostic and Therapeutic Advances“Understanding why some people develop PTSD and depression and others don’t is a major challenge,” said investigator Charles B. Nemeroff, M.D., PhD, chair of the Department of Psychiatry and Behavioral Sciences at Dell Medical School of UT Austin. “We found that the brains of people with these disorders have molecular differences, especially in the prefrontal cortex. These changes seem to affect things like our immune system, how our nerves work, and even how our stress hormones behave.”The genetic components of the work built on a study published last month by researchers including Ressler and Daskalakis in Nature Genetics, in which they identified 95 locations, or loci in the genome (including 80 new) associated with PTSD. Their multi-omic analyses found 43 potential causal genes for the disorder.The researchers now could reveal only limited overlap between the top genes and those implicated in GWAS studies, underscoring the gap in current understanding between disease risk and underlying disease processes. In contrast, they discovered greater correlations between brain multi-omics and blood markers.“Our findings support the development of brain-informed blood biomarkers for real-time profiling,” said Daskalakis.Ressler added, “These biomarkers could help overcome current challenges in obtaining brain biopsies for advancing new treatments.”Future DirectionsLimitations of the study include the inherent biases in postmortem brain research, including population selection, clinical assessment, comorbidities, and end-of-life state. The authors also caution that they did not fully characterize all cell subtypes and cell states and that future studies are required to understand contrasting molecular signals across omics or brain regions.The team plans on using this database as groundwork for future analysis of how genetic factors interact with environmental variables to create downstream disease effects.“Learning more about the molecular basis of these conditions, PTSD and MDD, in the brain paves the way for discoveries that will lead to more effective therapeutic and diagnostic tools. This work was possible because of the brain donations to the Lieber Institute Brain Repository from families whose loved ones died of these conditions,” said Joel Kleinman, MD, PhD, associate director of Clinical Sciences at the Lieber Institute for Brain Development. “We hope our research will one day bring relief to individuals who struggle with these disorders and their loved ones.”For more on this research, see New Molecular Insights Into PTSD and Depression.Reference: “Systems biology dissection of PTSD and MDD across brain regions, cell types, and blood” by Nikolaos P. Daskalakis, Artemis Iatrou, Chris Chatzinakos, Aarti Jajoo, Clara Snijders, Dennis Wylie, Christopher P. DiPietro, Ioulia Tsatsani, Chia-Yen Chen, Cameron D. Pernia, Marina Soliva-Estruch, Dhivya Arasappan, Rahul A. Bharadwaj, Leonardo Collado-Torres, Stefan Wuchty, Victor E. Alvarez, Eric B. Dammer, Amy Deep-Soboslay, Duc M. Duong, Nick Eagles, Bertrand R. Huber, Louise Huuki, Vincent L. Holstein, Mark W. Logue, Justina F. Lugenbühl, Adam X. Maihofer, Mark W. Miller, Caroline M. Nievergelt, Geo Pertea, Deanna Ross, Mohammad S. E. Sendi, Benjamin B. Sun, Ran Tao, James Tooke, Erika J. Wolf, Zane Zeier, PTSD Working Group of Psychiatric Genomics Consortium**, Sabina Berretta, Frances A. Champagne, Thomas Hyde, Nicholas T. Seyfried, Joo Heon Shin, Daniel R. Weinberger, Charles B. Nemeroff, Joel E. Kleinman and Kerry J. Ressler, 24 May 2024, Science.DOI: 10.1126/science.adh3707Disclosures: Nikolaos P. Daskalakis is on the scientific advisory boards for BioVie Inc., Circular Genomics, Inc., and Feel Therapeutics, Inc.; Daniel R. Weinberger is on the advisory boards of Pasithea Therapeutics and Sage Therapeutics for unrelated work; Duc M. Duong is a cofounder of ARC Proteomics, and cofounder and paid consultant of Emtherapro Inc.; Chia-Yen Chen is an employee of Biogen Inc.; Mohammad S. E Sendi receives consulting fees for unrelated work from Niji Corp, Benjamin B. Sun is an employee and stockholder of Biogen Inc.; Kerry J. Ressler has received consulting income from Alkermes and sponsored research support from Brainsway and Takeda, and is on the scientific advisory boards for Janssen, Verily, and Resilience Therapeutics for unrelated work.Funding: This work was supported by grants from NIMH, the Brain & Behavior Research Foundation, Stichting Universitas / the Bontius Foundation, the Dutch Research Council (NWO) fund, and McLean Hospital.

Study reveals molecular distinctions and similarities in PTSD and depression, highlighting potential therapeutic targets and biomarkers. A comprehensive examination of multiple biological processes is essential...

PTSD Brain Differences Art

Researchers from McLean Hospital and collaborating institutions have discovered shared and distinct molecular changes in brain regions, genomic layers, cell types, and blood of individuals with PTSD and MDD, offering new insights for therapeutic and diagnostic advancements. Credit: SciTechDaily

Study reveals molecular distinctions and similarities in PTSD and depression, highlighting potential therapeutic targets and biomarkers.

A comprehensive examination of multiple biological processes is essential for understanding the development of stress-related disorders. Recent research conducted by scientists at McLean Hospital, along with collaborators from The University of Texas at Austin and Lieber Institute for Brain Development, has revealed both shared and unique molecular changes in brain regions, genomic layers, cell types, and blood among individuals with posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). These findings, published in Science, could pave the way for innovative treatments and biomarkers.

The Complexity of PTSD Explored

“PTSD is a complex pathological condition. We had to extract information across multiple brain regions and molecular processes to capture the biological networks at play,” explained lead author Nikolaos P. Daskalakis, MD, PhD.

Stress-related disorders develop over time, stemming from epigenetic modifications caused by the interplay between genetic susceptibility and traumatic stress exposure. Although previous research has identified factors such as hormonal, immune, methylomic, and transcriptomic influences, the limited availability of postmortem brain tissues from PTSD patients has hindered a comprehensive understanding of these brain-based molecular changes.

Multi-omics Approach to Studying PTSD and Depression

“Our primary goals for this study were to interpret and integrate differential gene and protein expression, epigenetic alterations and pathway activity across our postmortem brain cohorts in PTSD, depression and neurotypical controls,” said senior author Kerry Ressler, MD, PhD, chief scientific officer and director of Division of Depression and Anxiety Disorders and Neurobiology of Fear Laboratory at McLean Hospital, and a professor of psychiatry at Harvard Medical School. “We essentially combined circuit biology with powerful multi-omics tools to delve into the molecular pathology behind these disorders.”

For this, the team analyzed multi-omic data from 231 PTSD, MDD, and neurotypical control subjects, along with 114 individuals from replication cohorts for differences in three brain regions — the medial prefrontal cortex (mPFC), hippocampal dentate gyrus (DG) and central nucleus of the amygdala (CeA). They also performed single-nucleus RNA sequencing (snRNA-seq) of 118 PFC samples to study cell-type-specific patterns and evaluated blood-based proteins in more than 50,000 UK Biobank participants to isolate key biomarkers associated with stress-related disorders. Finally, the overlap of these key brain-based disease process genes was compared with genome-wide association studies (GWAS)-based risk genes to identify PTSD and MDD risk.

Molecular Variations and Disease Mechanisms

Individuals with PTSD and MDD shared altered gene expression and exons in the mPFC but differed in the localization of epigenetic changes. Further analysis revealed that a history of childhood trauma and suicide were strong drivers of molecular variations in both disorders. The authors noted that MDD disease signals were more strongly associated with male-specific results, suggesting that sex differences may underlie disease risk.

Top disease-associated genes and pathways across regions, omics, and/or traits implicated biological processes in both neuronal and non-neuronal cells. These included molecular regulators and transcription factors, and pathways involved in immune function, metabolism, mitochondria function, and stress hormone signaling.

Implications for Diagnostic and Therapeutic Advances

“Understanding why some people develop PTSD and depression and others don’t is a major challenge,” said investigator Charles B. Nemeroff, M.D., PhD, chair of the Department of Psychiatry and Behavioral Sciences at Dell Medical School of UT Austin. “We found that the brains of people with these disorders have molecular differences, especially in the prefrontal cortex. These changes seem to affect things like our immune system, how our nerves work, and even how our stress hormones behave.”

The genetic components of the work built on a study published last month by researchers including Ressler and Daskalakis in Nature Genetics, in which they identified 95 locations, or loci in the genome (including 80 new) associated with PTSD. Their multi-omic analyses found 43 potential causal genes for the disorder.

The researchers now could reveal only limited overlap between the top genes and those implicated in GWAS studies, underscoring the gap in current understanding between disease risk and underlying disease processes. In contrast, they discovered greater correlations between brain multi-omics and blood markers.

“Our findings support the development of brain-informed blood biomarkers for real-time profiling,” said Daskalakis.

Ressler added, “These biomarkers could help overcome current challenges in obtaining brain biopsies for advancing new treatments.”

Future Directions

Limitations of the study include the inherent biases in postmortem brain research, including population selection, clinical assessment, comorbidities, and end-of-life state. The authors also caution that they did not fully characterize all cell subtypes and cell states and that future studies are required to understand contrasting molecular signals across omics or brain regions.

The team plans on using this database as groundwork for future analysis of how genetic factors interact with environmental variables to create downstream disease effects.

“Learning more about the molecular basis of these conditions, PTSD and MDD, in the brain paves the way for discoveries that will lead to more effective therapeutic and diagnostic tools. This work was possible because of the brain donations to the Lieber Institute Brain Repository from families whose loved ones died of these conditions,” said Joel Kleinman, MD, PhD, associate director of Clinical Sciences at the Lieber Institute for Brain Development. “We hope our research will one day bring relief to individuals who struggle with these disorders and their loved ones.”

For more on this research, see New Molecular Insights Into PTSD and Depression.

Reference: “Systems biology dissection of PTSD and MDD across brain regions, cell types, and blood” by Nikolaos P. Daskalakis, Artemis Iatrou, Chris Chatzinakos, Aarti Jajoo, Clara Snijders, Dennis Wylie, Christopher P. DiPietro, Ioulia Tsatsani, Chia-Yen Chen, Cameron D. Pernia, Marina Soliva-Estruch, Dhivya Arasappan, Rahul A. Bharadwaj, Leonardo Collado-Torres, Stefan Wuchty, Victor E. Alvarez, Eric B. Dammer, Amy Deep-Soboslay, Duc M. Duong, Nick Eagles, Bertrand R. Huber, Louise Huuki, Vincent L. Holstein, Mark W. Logue, Justina F. Lugenbühl, Adam X. Maihofer, Mark W. Miller, Caroline M. Nievergelt, Geo Pertea, Deanna Ross, Mohammad S. E. Sendi, Benjamin B. Sun, Ran Tao, James Tooke, Erika J. Wolf, Zane Zeier, PTSD Working Group of Psychiatric Genomics Consortium**, Sabina Berretta, Frances A. Champagne, Thomas Hyde, Nicholas T. Seyfried, Joo Heon Shin, Daniel R. Weinberger, Charles B. Nemeroff, Joel E. Kleinman and Kerry J. Ressler, 24 May 2024, Science.
DOI: 10.1126/science.adh3707

Disclosures: Nikolaos P. Daskalakis is on the scientific advisory boards for BioVie Inc., Circular Genomics, Inc., and Feel Therapeutics, Inc.; Daniel R. Weinberger is on the advisory boards of Pasithea Therapeutics and Sage Therapeutics for unrelated work; Duc M. Duong is a cofounder of ARC Proteomics, and cofounder and paid consultant of Emtherapro Inc.; Chia-Yen Chen is an employee of Biogen Inc.; Mohammad S. E Sendi receives consulting fees for unrelated work from Niji Corp, Benjamin B. Sun is an employee and stockholder of Biogen Inc.; Kerry J. Ressler has received consulting income from Alkermes and sponsored research support from Brainsway and Takeda, and is on the scientific advisory boards for Janssen, Verily, and Resilience Therapeutics for unrelated work.

Funding: This work was supported by grants from NIMH, the Brain & Behavior Research Foundation, Stichting Universitas / the Bontius Foundation, the Dutch Research Council (NWO) fund, and McLean Hospital.

Read the full story here.
Photos courtesy of

Related News

Green leader Adrian Ramsay: Labour’s ‘growth v nature’ framing is an outrage

Co-leader says deprioritisation of net zero is ‘extremely dangerous’ as he rejects ‘nimby-in-chief’ characterisationLabour’s push for economic growth at the expense of climate and nature is “extremely dangerous”, the co-leader of the Green party has said.Adrian Ramsay, the MP for Waveney Valley between Norfolk and Suffolk, was one of the five Green MPs elected to parliament last July in their best ever result. He said and his colleagues knew they would be holding Labour to account, but did not expect to be as disappointed as they have been. Continue reading...

Labour’s push for economic growth at the expense of climate and nature is “extremely dangerous”, the co-leader of the Green party has said.Adrian Ramsay, the MP for Waveney Valley between Norfolk and Suffolk, was one of the five Green MPs elected to parliament last July in their best ever result. He said and his colleagues knew they would be holding Labour to account, but did not expect to be as disappointed as they have been.In recent weeks, Labour has given the green light to airport expansion and vowed to change planning rules to deprioritise nature, while ministers have repeatedly disparaged bats and newts and ridiculed measures to protect fish. The chancellor Rachel Reeves has suggested economic growth trumps the government’s legally binding target of reaching net zero emissions by 2050, and there are suggestions the national wealth fund, meant for green projects, will be coopted for defence.Ramsay said: “This whole depiction the government’s coming up with is completely false and actually extremely dangerous, because green spaces are crucial to people’s wellbeing, crucial to the natural environment, and we can and must do development in a way that not just protects nature … the government is signed up to a requirement to restore 30% of land and sea in the UK for nature by 2030.“And when Labour talks about growth versus nature, it sort of castigates communities who are working to protect their community, protect the environment from being trodden on by a planning system that that should be there to protect them, but the government’s looking at removing those safeguards.”Ramsay also questioned whether Boris Johnson was a greener prime minister than Keir Starmer, saying: “[Johnson] did have some understanding of the need to regenerate the natural world, which Labour are very weak on. While there were early signs of some positive moves on renewable energy targets, that’s now being undermined by climate-wrecking decisions around things like airport expansion.”Ramsay, who is co-leader with fellow MP Carla Denyer, has had a bruising start to his parliamentary career. One of his biggest critics has been Ed Miliband, the energy secretary, who has accused him of being against renewable infrastructure.Miliband’s criticisms of Ramsay have resulted in the Green MP being labelled the “UK’s nimby-in-chief” after he used his first day in parliament to call for a pause on plans for a route of 520 pylons passing through his constituency. Ramsay says he is representing his constituents, who want alternatives to pylons to be discussed before they are built. His critics, including Miliband, say alternatives are too slow and expensive to implement and will impede the government in reaching its target to decarbonise the grid by 2030.Before Ramsay was an MP, he was for many years a Green councillor and worked for renewables campaign groups. Of being referred to as a nimby, he said: “I think that the claims are so absurd that they are laughable. I mean, people have called me Mr Renewables, because my whole career and campaigning background since I was a teenager has been in advancing action on climate and in particular action on renewables. I’m the first to say we’ve got to see more renewables.”MPs for the rightwing Reform party have also opposed pylons as part of their drive to cancel net zero, of which Ramsay said: “Reform have jumped on a bandwagon quite recently. There’s been a cross-party group with the other four parties in East Anglia, working on these issues for some time.” He said the party was “selling people a pup” because “they’re trying to pretend that they’re there to support the ordinary person, but their policies would undermine the NHS, allow the ultra-rich plutocrats from abroad to buy up our democracy, and crucially, would stop the drive for net zero, which will bring down people’s bills and keep people’s homes warm.”There are also rumours that Labour is considering weakening plans aimed at ensuring all new homes are powered by renewables. Government sources say new homes will be “technology agnostic”, allowing housebuilders to meet climate targets how they like, rather than mandating solar panels and heat pumps.skip past newsletter promotionThe planet's most important stories. Get all the week's environment news - the good, the bad and the essentialPrivacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy. We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply.after newsletter promotion“It would be an absolute outrage if the Labour government does not require renewable energy in all new homes,” Ramsay said. “People say to me all the time, why on earth are we seeing new homes being built without solar panels, without renewable heating systems? And the only reason the government wouldn’t do this is if they caved into the developers, because it’s a win-win all the way around.”Ramsay said he would continue to challenge Miliband. “My challenge to Ed Miliband is, don’t undermine the whole of your national strategy by allowing this major airport expansion to go ahead,” he said.“Don’t allow the whole of your carbon plan to be completely undermined by allowing the new Rosebank oilfield. They’re failing to focus on energy efficiency, how we insulate people’s homes to bring bills down, you’ve got to look at energy reduction as well as renewables if we’re going to deliver a green future.“And in terms of nature, they’re actively opposing the nature restoration agenda with this damaging suggestion that that economic success and nature are somehow at loggerheads. So that’s what’s led environmental campaigners like George Monbiot to increasingly suggest that Labour may be even worse on the environment than the Conservatives were.”

Nature
Climate
Government

A Story About Salmon That Almost Had a Happy Ending

How tribal leaders, commercial fisherman and a few small environmental groups won an uphill campaign against dams.

Completion of the world’s largest dam removal project — which demolished four Klamath River hydroelectric dams on both sides of the California-Oregon border — has been celebrated as a monumental achievement, signaling the emerging political power of Native American tribes and the river-protection movement.True enough. It is fortunate that the project was approved in 2022 and completed last October, before the environmentally hostile Trump administration could interfere, and it is a reminder that committed, persistent campaigning for worthy environmental goals can sometimes overcome even the most formidable obstacles.How tribal leaders, commercial fisherman and a few modestly sized environmental groups won an uphill campaign to dismantle the dams is a serpentine, setback-studded saga worthy of inclusion in a collection of inspirational tales. The number of dams, their collective height (400 feet⁠⁠) and the extent of potential river habitat that has been reopened to salmon (420 miles⁠⁠) are all unprecedented.⁠The event is a crucial turning point, marking an end to efforts to harness the Klamath’s overexploited waterways to generate still more economic productivity, and at last addressing the basin’s many environmental problems by subtracting technology instead of adding it, by respecting nature instead of trying to overcome it. It’s an acknowledgment that dams have lifetimes, like everything else, and that their value in hydropower and irrigated water often ends up being dwarfed by their enormous environmental and social costs.

Nature
Technology
Water

How nature organizes itself, from brain cells to ecosystems

McGovern Institute researchers develop a mathematical model to help define how modularity occurs in the brain — and across nature.

Look around, and you’ll see it everywhere: the way trees form branches, the way cities divide into neighborhoods, the way the brain organizes into regions. Nature loves modularity — a limited number of self-contained units that combine in different ways to perform many functions. But how does this organization arise? Does it follow a detailed genetic blueprint, or can these structures emerge on their own?A new study from MIT Professor Ila Fiete suggests a surprising answer.In findings published Feb. 18 in Nature, Fiete, an associate investigator in the McGovern Institute for Brain Research and director of the K. Lisa Yang Integrative Computational Neuroscience (ICoN) Center at MIT, reports that a mathematical model called peak selection can explain how modules emerge without strict genetic instructions. Her team’s findings, which apply to brain systems and ecosystems, help explain how modularity occurs across nature, no matter the scale.Joining two big ideas“Scientists have debated how modular structures form. One hypothesis suggests that various genes are turned on at different locations to begin or end a structure. This explains how insect embryos develop body segments, with genes turning on or off at specific concentrations of a smooth chemical gradient in the insect egg,” says Fiete, who is the senior author of the paper. Mikail Khona PhD '25, a former graduate student and K. Lisa Yang ICoN Center graduate fellow, and postdoc Sarthak Chandra also led the study.Another idea, inspired by mathematician Alan Turing, suggests that a structure could emerge from competition — small-scale interactions can create repeating patterns, like the spots on a cheetah or the ripples in sand dunes.Both ideas work well in some cases, but fail in others. The new research suggests that nature need not pick one approach over the other. The authors propose a simple mathematical principle called peak selection, showing that when a smooth gradient is paired with local interactions that are competitive, modular structures emerge naturally. “In this way, biological systems can organize themselves into sharp modules without detailed top-down instruction,” says Chandra.Modular systems in the brainThe researchers tested their idea on grid cells, which play a critical role in spatial navigation as well as the storage of episodic memories. Grid cells fire in a repeating triangular pattern as animals move through space, but they don’t all work at the same scale — they are organized into distinct modules, each responsible for mapping space at slightly different resolutions.No one knows how these modules form, but Fiete’s model shows that gradual variations in cellular properties along one dimension in the brain, combined with local neural interactions, could explain the entire structure. The grid cells naturally sort themselves into distinct groups with clear boundaries, without external maps or genetic programs telling them where to go. “Our work explains how grid cell modules could emerge. The explanation tips the balance toward the possibility of self-organization. It predicts that there might be no gene or intrinsic cell property that jumps when the grid cell scale jumps to another module,” notes Khona.Modular systems in natureThe same principle applies beyond neuroscience. Imagine a landscape where temperatures and rainfall vary gradually over a space. You might expect species to be spread, and also to vary, smoothly over this region. But in reality, ecosystems often form species clusters with sharp boundaries — distinct ecological “neighborhoods” that don’t overlap.Fiete’s study suggests why: local competition, cooperation, and predation between species interact with the global environmental gradients to create natural separations, even when the underlying conditions change gradually. This phenomenon can be explained using peak selection — and suggests that the same principle that shapes brain circuits could also be at play in forests and oceans.A self-organizing worldOne of the researchers’ most striking findings is that modularity in these systems is remarkably robust. Change the size of the system, and the number of modules stays the same — they just scale up or down. That means a mouse brain and a human brain could use the same fundamental rules to form their navigation circuits, just at different sizes.The model also makes testable predictions. If it’s correct, grid cell modules should follow simple spacing ratios. In ecosystems, species distributions should form distinct clusters even without sharp environmental shifts.Fiete notes that their work adds another conceptual framework to biology. “Peak selection can inform future experiments, not only in grid cell research but across developmental biology.”

Nature
Animals
Forests

From polar bears to polar vortex: How Columbia Sportswear uses nature to protect us from it

I’m standing on a corner in Reykjavík, the most flagrantly fragrantly delicious cinnamon roll I have ever had in my hand, and I am pouring sweat. It’s not because I worked hard to get this blissful brauð; it’s a leisurely 10-minute walk from my hotel. It’s not because it’s unseasonably warm; it’s Iceland in late […] The post From polar bears to polar vortex: How Columbia Sportswear uses nature to protect us from it appeared first on Popular Science.

I’m standing on a corner in Reykjavík, the most flagrantly fragrantly delicious cinnamon roll I have ever had in my hand, and I am pouring sweat. It’s not because I worked hard to get this blissful brauð; it’s a leisurely 10-minute walk from my hotel. It’s not because it’s unseasonably warm; it’s Iceland in late September and a brisk 40 degrees Fahrenheit. It’s because I’m wearing Columbia Sportswear Omni-Heat Infinity baselayers, and I have underestimated their insulating capacities—a mistake I will not make twice. It’s a mistake I shouldn’t have made at all. I spent several days prior testing out breathable membranes and thermal-reflective tech. Columbia’s gold metallic foil—introduced in 2021—helped insulate Intuitive Machines’ lunar lander when it was sent to the actual Moon in February 2024 (and when it launched again in 2025). In space, nobody can hear you sweat, but I’m walking through landscapes that only resemble Mars. And I’m audibly panting. I’ve trudged across the Solheimajokull glacier and been told that Omni-Heat Infinity would be a bit extra for those circumstances, so why I thought I needed it for a casual city stroll, well, I’m feeling the heat from that … I’m taking the heat for that. I packed Omni-Heat Infinity in case temperatures plunged below freezing. I should have stuck with what I’m actually in Iceland to learn about: Omni-Heat Arctic, Columbia Sportswear’s latest insulation system developed through research on polar bear pelts and demonstrated on less carb-focused, more high-output adventures. And what better place to test fabrics than where weather is constantly in flux. Iceland is a land of layers—both wandered and worn. On the Mid-Atlantic Ridge, where the Eurasian and North American plates slowly separate, the country is resigned to be redesigned as the Earth shifts and strains. But because a place is cold doesn’t mean it is unkind. A close-knit society on an unraveling rock, the Iceland I experience is a warm, self-reliant culture that demands warm, resilient clothes. I’ve only been in the country a few hours before I see a new road being freshly graded on top of what looks like last week’s lava. I’ve only been in the country a few more hours before it rains, shines, pours, and then the clouds part. Over the course of one day I’ll be doused winding behind the wind-whipped waterfalls, snake between surging sneaker waves, then scramble up the ashy veins of ice ridges. For every hour that’s brooding and bleak along the black sand coastline, there will be one that’s calm and bright beside thermal rivers. Hiking through the Reykjadalur Valley, we meet Skylar, who is backpacking solo through Europe and proudly shows off his one constant companion: a Columbia Sportswear flannel. Tranquility. Volatility. “If you don’t like the weather, wait five minutes” is a fitting expression and apt alert that you should always approach travel in Iceland with all manner of apparel handy. It’s a saying you’re just as likely to hear in Beaverton, Oregon, home to the Columbia Sportswear Company. Field-testing in Iceland is a first for our host, Director of Communications Andy Nordhoff, but this type of terrain isn’t foreign. Oregon may not be constantly altered by tectonic tension the way Iceland is, but it’s no stranger to maritime influences and geothermal forces. It’s a dramatic backdrop shaped by the slow grind of time and upheaval—weathered smooth in places, rough in others. It’s a landscape that has shaped Columbia since the company was formed in 1938. What started as a hat company is now one tough mother of an outfitter producing apparel and accessories for challenging environments.   And if there’s one thing folks from Oregon and Iceland know, it’s that there’s nothing worse than standing in a coat that has you remembering rather than feeling what it’s like to be warm or dry. To be present in adventures, you can’t be worrying about your clothes. A majority of activities in Iceland—from exploratory tourism to olfactory art collectives—are anchored in cultural reverence for natural resources and capturing the rejuvenating aura of the outdoors. And in a way, that’s the concept behind Omni-Heat Arctic, a solar-capture system. But before I found myself wrapped up in a fleece appreciating untamed beauty, Columbia’s in-house scientists spent years wrapped up in how nature solved the problem of thriving at extremes. Speaking from the Columbia campus, Dr. Haskell Beckham, vice president of innovation, explains how the company set out to “have the warmest jacket without the weight of a giant, damp puffer.” A puffer is, in the most basic terms, a bunch of chopped-up material stuffed in fabric. There’s down, there’s synthetic insulation, but it’s no matter what it’s operating with trapped air, which is low thermal conductivity. Still, humans constantly radiate heat, so the silver metallic Omni-Heat lining was introduced in 2010 to block that loss and reflect it back. Fast forward to 2021, and Omni-Heat Infinity introduced more surface coverage without impacting breathability, now with gold dots to tell the difference. Either way, they stood up to accelerated abrasion testing and real-world comfort testimonials. Plus the off-world partnerships with Intuitive Machines, who spoke the same language of thermal emissivity and solar reflectivity. So, having successfully applied materials science to space, the Columbia lab started thinking about icons of the most extreme environments on Earth. And Arctic inhabitants quickly came up. Digging into scientific literature about polar bears, however, revealed gaps in the understanding of how they survive. So Beckham knew he had to get his hands on a polar bear pelt. After trying the Oregon Zoo, Beckham followed a suggestion to contact the Burke Museum of Natural History at the University of Washington in Seattle. It turned out they did have a pelt that he could check out, like a library book, and he brought it back to the Portland area where it was studied for a year—placed in environmental chambers to measure how it reacted under a solar simulator at various watts per meter squared to mimic what it might see in a cold, yet sunny environment. And that’s when the Columbia team was able to shine some light on how polar pelts absorb light. “We discovered that the fur itself is actually translucent, but not transparent,” explains Beckham. “This lets a degree of solar energy transmission through the fur. And the bear’s skin is pigmented, which helps convert solar energy into heat—just like a black T-shirt in a warm environment feels warmer than a white T-shirt, which reflects solar radiation. With this system the pelt harvested solar energy and converts it to heat, so we set about creating materials and material stacks that have the same effect, which is partially about color and partially about density.” The end result, Omni-Heat Arctic, applies this discovery with thinner outer layers that allow sunlight to penetrate to the insulation (the equivalent of the underfur) and be converted closer to the body. However, unbroken black fabrics wouldn’t work, as the heat collects at the surface and is lost to the environment. It was imperative the solar radiation bypass the shell, go through the insulation, and be absorbed in a lining. For the Arctic Crest Down Jacket, the Columbia lab finally settled on a lining patterned with triangles and dots. Multi-layered engineering allowed the material to have a layer of metal topped with a coating featuring a black pigment. That black coating absorbs the solar radiation and converts it to heat, which is then conducted toward the body, while also protecting that heat from dissipating into the cold. And the team knew they nailed it when beta testers made unprompted comments about how it felt like the warmth amplified after the sun comes out, despite the external temperature.        “It’s a solar-boosted heat … like a biological greenhouse effect,” says Beckham. “That’s why the pattern on the puffer resembles a geodesic dome. On top of that, it’s a warmer jacket even when there’s no sunshine, thanks to how we engineer materials. “The fleece works a bit differently since they don’t have that special low E [low emissivity] coating, but [the high pile and black yarn lining] do work in that way a pelt naturally works.” As straightforward as all that sounds, Beckham’s research produced insight that challenged conventional wisdom, showing it’s not as simple as sunlight transferred through fur onto skin equals warmth. The fur density varies across the pelt, and as little as 3.5 percent of the light sometimes reaches the skin. So, an open question still remains about why the polar bear’s skin is black and what part it versus the fur truly plays in thermal regulation.  This, in a way, makes Omni-Heart Arctic an evolution, even an improvement on the natural means of solar transference. Confirmed by heat flux sensors, control of insulation, shell fabric/coating, lining, and moisture-resistant overlays allowed for garments with up to three times heat retention plus performance-oriented attributes. Core areas needing thicker covering and other areas needing flexibility and breathability can be targeted, while selectively absorbing sunlight promotes warmth without harmful exposure to UV.  Before this trip, my perspective on polar bears boiled down to “If it’s brown, lay down; if it’s black, fight back; if it’s white, say goodnight.” Now, I can appreciate what these creatures and Columbia Sportswear have done to address my mammalian shortcomings. Of course, when you think of a polar bear soaking up the Arctic sun, there’s a good chance you imagine it’s floating on an iceberg. While we didn’t go that far to test our textiles, we did take a sizable amount of moisture into consideration.  The Seljalandsfoss and Skogafoss waterfalls feel like veils between worlds—permeable but formidable. Piercing the multiverse requires preparation, however, and Columbia made sure we were ready with the OutDry Extreme Wyldwood shell jacket and pants. Thrown over the zip-up fleece, OutDry Extreme provided an impervious barrier without forming a moist bubble. With the hydrophobic film-like membrane laminated on the exterior (as opposed to the interior, topped by DWR-coated fabric), I didn’t worry about wet out or wet within. This orientation enhances breathability, allowing the interior fabric to wick perspiration away and more evenly distribute moisture vapor movement so no area gets overloaded. And as someone who constantly runs hot, I can vouch for its effectiveness. The Konos TRS OutDry Mid shoe kept my feet equally dry, stable, and cushioned throughout trail and town (and they remain my rainy day sneaker boots). Having a successful solution doesn’t mean Beckham and his team aren’t looking at new bio-inspired emulations that can improve outdoor apparel, however. The water-repellent properties of the lotus leaf are of interest, as the plant’s microstructure enables water droplets to bead up and roll off effortlessly. This could lead to durable, chemical-free, water-resistant gear. And the structural color of butterfly wings, where microscopic structures rather than pigments create hues, could lead to vivid, long-lasting color without dyes—another sustainable solution. From the 3D printers and swatch prototypes in their fab lab to the computational modeling that allows them to go through infinite combinations of inspirations and materials, the Columbia Sportswear scientists pursue innovation and efficiency.   I’ve now lived in the Arctic Crest Down Jacket and Arctic Crest Sherpa Fleece from one shoulder season to the next, trudging through the most brutally cold winter in a decade. Soon, it will be time to hang them up in favor of windbreakers and lightweight rain shells. In the not-so-distant future, Columbia Sportswear will have cooling technologies to reveal. But the polar vortex surged southward again as I started outlining this piece. Despite the spring-like weather that followed, early-morning hiking and biking isn’t exactly balmy yet. And there are always new latitudes to explore with the right daypack. So, as long as there’s even a hint of crispness or clouds in the years to come, I’m happy to bundle up in biomimicry to help me grin and, well, bear it, warm as a fresh cinnamon roll. The post From polar bears to polar vortex: How Columbia Sportswear uses nature to protect us from it appeared first on Popular Science.

Nature
Science
Culture

Even Ground Squirrels Got In on the Vole Feast Last Summer

For the first time, scientists documented concerted carnivory by California ground squirrels. But why were there so many voles? The post Even Ground Squirrels Got In on the Vole Feast Last Summer appeared first on Bay Nature.

By last summer, University of Wisconsin–Eau Claire professor Jennifer Elaine Smith had been studying California ground squirrels at Briones Regional Park for twelve years. There wasn’t much these rodents could do that could surprise her.  Then her team saw a ground squirrel stalk, hunt, and eat a California vole. It wasn’t a fluke, like some weirdly motivated or superintelligent squirrel. Because, as the researchers found, the squirrels kept doing it. Again and again. They weren’t sit-and-wait-type predators, but instead chased down the voles over short stretches of dirt. The research team documented 27 individual squirrels hunting voles that summer. “I could barely believe my eyes,” says Sonja Wild, a postdoctoral research fellow in the UC Davis Environmental Science and Policy department who co-authored a paper in the Journal of Ethology on the unusual phenomenon. “From then, we saw that behavior almost every day. Once we started looking, we saw it everywhere.” A California ground squirrel on the move with its unusual prey: a California vole. Normally, ground squirrels eat a mostly plant-forward diet. (Sonja Wild/UC Davis)It was easy to see what was triggering it: there were just so many voles around. “This was shocking,” says Smith, a University of Wisconsin-Eau Claire professor who studies social mammals and lead-authored the paper, which was published in December last year. “We had never seen this behavior before.”  California ground squirrels (Otospermophilus beecheyi), on most days, have a plant-forward diet. They have also been known to eat meat such as bird eggs, hatchlings, insects, or each other on occasion—but this is the first time in nature that they had ever been documented hunting and eating California voles. “The widespread nature of vole hunting in our population fundamentally changes our understanding of this primarily granivorous species, suggesting that they are considerably more flexible in their diet than previously assumed,” the researchers wrote. California voles (Microtus californicus) are a burrowing rodent species that range from southern Oregon down to Baja California—sometimes living (dangerously?) in ground squirrel burrows. They are ubiquitous, but since they live underground, I usually only see a handful of these rodents every year.  That all changed last year. Female voles can have back-to-back litters—every 21 days—if conditions are right. Just imagine. (Vishal Subramanyan)A heck of a lot of voles In May, I was hiking in Sycamore Grove Park, a regional preserve in Livermore that I’ve been visiting for over seven years. As a wildlife photographer, I spend a lot of time in nature: being still and quiet, watching for animals. This time, from the start, I saw dozens of these tiny rodents running all over the trails. I’d only seen a couple of voles in this park over the years. I saw more of them in a few minutes than I had over the past several years. Throughout the course of my hike, I counted over 100 voles. It was a photographer’s dream. I hunched down and took dozens of photos as the voles scurried through fields, climbed on stalks, and ran in and out of their burrows. It appeared Northern California was in the midst of a vole population boom. Reports emerged of huge surges in their numbers, from San Francisco to Pleasanton to the El Dorado Hills, east of Sacramento. Smith’s team, crunching numbers from the community science platform iNaturalist, reported people logged seven times as many vole sightings in California as the average over the past decade. Livermore, like Briones Regional Park, was crawling with California voles last summer. (Vishal Subramanyan)Booms like this have occurred in the past. Just like their more famous cousins the lemmings, vole populations sometimes just go through the roof—reaching densities of up to 5,000 animals per acre. To humans, these booms may seem random. Vole populations typically cycle up and down over periods of three or four years, Smith says, but this was the biggest boom she saw over twelve years of study.  One thing that’s clear: Peak Vole is achieved by female voles reproducing at much higher rates than usual, according to Phoebe Edwards. She studied meadow vole population cycles for her Ph.D. thesis and is now an assistant professor of ecology, evolution, and organismal biology at Iowa State University. “As they’re increasing from a low population density, the females that are sexually mature are having lots of litters rapidly, back to back,” Edwards says. “They can even become pregnant once they’ve just given birth, and not all mammals can do that.” Voles can give birth to new litters every 21 days, she says. At the boom’s peak, birth rates slow. What sets off such industrious behavior? Generally, Edwards says, it’s because an opportunity has arisen: there’s more food around (possibly because of the climate changing), or fewer predators, or “changes to landscape use where voles are colonizing new kinds of habitats that weren’t really suited to them before,” said Dr. Edwards. Everybody likes eating voles The ground squirrels, like many, took advantage of the situation. Over the summer of 2024, researchers observed them hunting voles on 74 occasions over just 18 days of fieldwork. Of these, 31 involved active hunting, with squirrels stalking through tall grass or chasing voles across open dirt. And the hunters were quite successful—17 of the 31 documented attempts (55 percent) resulted in a kill.  Sometimes, squirrels tolerated other squirrels grabbing their killed voles. But occasionally the researchers saw squirrels fighting over their prizes. That made sense, they wrote, because “the energy contained in a single vole far outweighs that of more common food items, such as seeds or grasses.”  Population booms of small mammals like voles impact whole ecosystems, affecting predators and other animals. A slew of animals prey on voles, as Smith and team noted in their paper—“hawks, owls, egrets, long-tailed weasels, coyotes, skunks, mountain lions, and garter snakes”—all of which likely had more to eat. Burrowing rodents like voles are often ecosystem engineers, too, creating tunnels that other animals use. So more voles could also mean more habitat for those species. But these booms don’t last forever—so as vole populations crash, predators may be once again forced to turn to other prey, and small animals will have fewer places to live.  While the vole boom was a boon for animals with a taste for rodents, it touched human lives a bit differently. Grape grower Dane Stark, who runs Page Mill Winery in Livermore, noticed one summer day that some unknown vandal had nibbled a ring out of the bark on many of his youngest vines. He waited and watched, and quickly learned that the culprits were voles. They got to nearly all his vines. “I’ve been growing grapes for twenty years, and this is the first time I’ve ever noticed something like this,” Stark says. He hoped that the surge in vole numbers would bring in more predators to help control their exploding populations. Researchers documented last summer’s sharp spike in iNaturalist observations of California voles in their paper in the Journal of Ethology. (Courtesy of the authors)Have we passed Peak Vole?  It’s hard to know when or if the vole population boom is over. It would likely require an intensive field survey to get an accurate idea of their numbers. However, on my recent hikes this winter, I’ve observed far fewer voles compared to last summer. Community science reports on platforms like iNaturalist, which were essential in recording the vole boom last year, may also help understand the timing of the boom’s end.  Bobcats were among those that likely cashed in on a surfeit of voles last summer, along with “hawks, owls, egrets, long-tailed weasels, coyotes, skunks, mountain lions, and garter snakes,” according to researchers. (Vishal Subramanyan)The boom also raises other ecological questions, such as whether California ground squirrels learn hunting strategies socially or if it is a genetic predisposition. Wild and Smith are also interested in disease implications of the novel squirrel–vole interaction. “Parasites might be shared between voles and squirrels,” says Smith. “Future research will reveal the extent to which these interactions have positive or potentially negative consequences for ground squirrel populations.”  I’ll remember it fondly, as a wildlife photographer, given the abundance of photo opportunities the voles gave me. One evening, at a local park in Fremont. Down on the ground, voles were scampering across the fields. I watched as a bobcat quietly stalked prey alongside the trail. After patiently waiting for a few minutes, the bobcat pounced, grabbing one of the many voles that scattered these fields. It immediately took the vole and started trotting towards the cover, disappearing over the ridge as the sun set. In a prey boom, the mandate is the same for photographers as for bobcats: strike while it’s hot.  VIDEO A video compilation of ground squirrels hunting. Note: this contains some graphic imagery. (Sonja Wild, UC Davis)

Nature
Animals
Energy

Suggested Viewing

Reboot

Humans have exploited Earth to the point where it is no longer possible to live on it. Their only option is to relocate to Mars. When the last group of people has boarded the spaceship for the red planet, the Earth can finally breathe easy. Like an expressionist painting, Reboot depicts a world in which the absence of our species is the only chance nature has to recover its lushness and flourish once more.

Animation
Crisis
Cosmos

The Fabricated Wild

The Fabricated Wild explores the intersections between the natural and artificial within the Florida wilderness using personal film-making technology. Images strictly of the natural landscape are sequenced to break from traditional cinematic viewing techniques. Images foreground the natural Florida landscape in the frame and communicate how cinema fabricates the expansive wilderness. The Fabricated Wild frames the complex interaction between a frustrated filmmaker and the collective unconsciousness of the natural environment, a theory outlined by Carl Jung, considering the implications and discoveries along the way. The film frames the experience of interacting with and revealing the forest’s collective unconsciousness that is frequently hidden in cinema to call for an experimental way to engage with the natural landscape. 16mm, Super 8.

Nature
Experimental
Student

Growing Hope

This is a short film focusing on multi-generational tree planting and the long-term benefits for ALL. Growing Hope amplifies the message of the non-profit www.grandtrees.org and its initiative to plant trees by young and old for a brighter future for us all.

Plants
Nature
Inspirational

Karibu Nyumbani

“Karibu Nyumbani” translates as “Welcome to my Home” in Swahili. Guides in the Maasai Mara have a deep-rooted pride, knowledge, and love for wildlife. This film encapsulates that passion from the perspective of George Osono, a guide in Mara North Conservancy, who completely embodies this spirit of caring for nature. Throughout the film, you meet Half Tail, Lola's cubs and the other iconic members of the Marsh Pride, Kweli the Cheetah and her three cubs as they prepare for adulthood, and an impressive elephant named Edwin. This film is visual portrait of the Maasai Mara's majestic wildlife, and the stories of the extraordinary animals that call it home. The film encourages people to see the beauty of these animals, recognise how fragile their existence is and in turn care more about protecting them.

Conservation
Animals
Nature

SeaMonster II

SeaMonster II is a single channel video with sound, duration 14:19. All the objects used in this performance were collected at the sea shore near the artist's studio on the island of Aegina. This work is part of the "SeaMonster" series. The first iteration "SeaMonster Monk" a live performance took place at the Athens Art Fair 2019 and was featured at the WhiteBox NYC in 2023.

Water
Pollution
Nature

Join us to forge
a sustainable future

Our team is always growing.
Become a partner, volunteer, sponsor, or intern today.
Let us know how you would like to get involved!

CONTACT US

sign up for our mailing list to stay informed on the latest films and environmental headlines.

Subscribers receive a free day pass for streaming Cinema Verde.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.