Wednesday, March 19, 2025

 

Virginia Tech study finds unique brain changes linked to witnessing trauma




Virginia Tech
(From left) Yeeun Bae and Morgan Patrick, both Ph.D. students, work with Associate Professor Tim Jarome to help identify distinct molecular differences in how the brains of victims and witnesses process trauma. 

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(From left) Yeeun Bae and Morgan Patrick, both Ph.D. students, work with Associate Professor Tim Jarome to help identify distinct molecular differences in how the brains of victims and witnesses process trauma.

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Credit: Photo by Marya Barlow for Virginia Tech.





For years, post-traumatic stress disorder (PTSD) has been studied primarily in people who experience trauma firsthand. But what about those who witness it — military veterans, first responders, health care workers, or bystanders to violence — who constitute 10 percent of all PTSD cases?

New research from Virginia Tech, published in PLOS ONE, reveals that witnessing trauma triggers unique brain changes, distinct from those caused by experiencing trauma firsthand. The study is the first to shed light on the molecular differences between directly acquired PTSD and bystander PTSD and could pave the way for changes in how the disorders are treated. 

“Currently, patients with directly acquired PTSD and bystander PTSD are treated the same way – with a combination of therapy and medication,” said Timothy Jarome, the project’s principal investigator and associate professor of neurobiology in the College of Agriculture and Life Sciences. “Our research suggests that indirect trauma and direct trauma create different biological responses, which could mean they require different treatment strategies that target distinct brain pathways.”

Understanding how observation leads to PTSD

Jarome’s research focuses on understanding the neurobiological mechanisms behind memory-related disorders, including PTSD, dementia, and Alzheimer’s disease. His interest in bystander PTSD arose after learning about PTSD symptoms reported in people who witnessed the deadly 2021 collapse of a Miami condominium.

“People who saw it from across the street reported that they were suffering from nightmares, insomnia, and anxiety,” he said. “They were showing symptoms of PTSD, but didn’t go through it or have any connection to the people in the building. We sought out to understand the brain mechanisms behind how that occurred.”

For the study, researchers focused on protein changes caused by a fear stimulus in three key brain regions involved in fear memory: the amygdala, the anterior cingulate cortex, and the retrosplenial cortex. They discovered that witnessing trauma triggered distinct protein degradation patterns in all three regions, compared to directly experiencing trauma. 

Additionally, they uncovered sex-specific differences in how male and female brains process indirect fear memories. These findings build on previous research from Jarome’s lab, which identified a specific protein, known as K-63 ubiquitin, linked to PTSD development in women.

“Our findings highlight significant biological differences in how male and female brains respond to witnessing trauma,” said the paper’s lead author, Shaghayegh Navabpour, a former Ph.D. student in translational biology, medicine, and health who is now a postdoctoral researcher at Stanford University. “These differences may help explain why women are twice as likely as men to develop PTSD, leading to more targeted treatments that consider these sex-specific factors.”

In future research, Jarome hopes to explore how these how these molecular pathways could be leveraged to develop more precise PTSD therapies. He also hopes to examine the role of empathy, which originates in a different brain region called the anterior insular cortex, in bystander PTSD.

The vital role of student researchers

The research was funded by a $420,000 grant from the National Institute of Mental Health, which is part of the National Institutes of Health. In addition to supporting equipment and materials costs of the research, the grant helped pay the stipends of graduate and undergraduate research assistants on the project.

“At academic institutions, students — undergraduate, graduate, and postdocs — are the driving force for research,” Jarome said. “While faculty members might secure the funding to do the projects, the reality is that the work is done by these students as they're going through their training. Without graduate students, especially, but also undergraduates and postdocs, science doesn't advance."

Navabpour, who earned her Ph.D. from Virginia Tech in 2023, is now working at Stanford to develop a drug to help treat Alzheimer’s disease.

“My time in Dr. Jarome’s lab was hugely valuable in shaping my career and preparing me for my current role as a postdoc and my goal of becoming a faculty member,” she said. “I learned how to think scientifically — how to ask the right questions and approach problems critically — and gained hands-on experience with key methods and techniques that continue to inform my research.”

  • Other members of research team included: 
  • Morgan Patrick, Ph.D. candidate, School of Neuroscience
  • Nour Omar ’23, who earned a degree in psychology, current Ph.D. candidate at Stanford University School of Medicine
  • Shannon Kincaid, Ph.D. candidate, School of Animal Sciences
  • Yeeun Bae, Ph.D. candidate, School of Animal Sciences
  • Jennifer Abraham ’24, who earned a degree in clinical neuroscience
  • Jacobi McGrew ’22, PREP Scholar intern, School of Animal Sciences
  • Madeline Musaus ’21, who earned a degree in clinical neuroscience
  • W. Keith Ray, senior researcher, Fralin Life Sciences Institute
  • Richard Helm, associate professor, Department of Biochemistry

 

Study shows that cannabidiol may be a promising agent for promoting dental biomineralization



Researchers tested different concentrations of the substance on dental pulp cells. Results show promise for dental tissue repair.



Fundação de Amparo à Pesquisa do Estado de São Paulo

Study shows that cannabidiol may be a promising agent for promoting dental biomineralization 

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Larissa Sthefani Sales, first author of the study, during the experiment in which she used cannabidiol as a stimulus for the cultivation of dental pulp cells and macrophages 

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Credit: Larissa Sthefani Sales

 



In vitro tests indicate that cannabidiol can stimulate the biomineralization of teeth even under inflammatory conditions, thus promoting tissue repair.

The research was conducted with the support of FAPESP at the Ribeirão Preto School of Dentistry of the University of São Paulo (FORP-USP) in Brazil. The results were published in the Journal of Dentistry.  

In the experiment, cells from the dental pulp of mice were exposed to a cytokine called tumor necrosis factor alpha (TNF-α), which is involved in various inflammatory and autoimmune processes. They were then treated with different concentrations of cannabidiol for periods ranging from 24 hours to seven days.

“The ability of the cells to survive and function in this environment was evaluated, which allowed us to determine if the substance has any bioactive effect on them,” explains Francisco Wanderley Garcia de Paula-Silva, professor at the institution’s Department of Pediatrics, who coordinated the work. The study had the collaboration of researchers Elaine Del Bel and Glauce Crivelaro do Nascimento Marangoni, from the Molecular Neurophysiology Laboratory at FORP-USP.  

In addition, the researchers studied the formation of mineralization nodules using a dye called alizarin red. This process takes place thanks to the presence of mesenchymal stem cells in the dental pulp, which, when exposed to some kind of stress, such as an inflammatory process, migrate to the affected areas and differentiate into odontoblast-like structures, cells that form and maintain dentin, the innermost layer of teeth.

At the same time, macrophages, important cells of the immune system, were pre-stimulated with bacterial lipopolysaccharide, a toxic component of the cell wall of gram-negative bacteria, before being exposed to the substance extracted from Cannabis sativa. This test was designed to evaluate the effect of cannabidiol in modulating the synthesis of inflammatory mediators by macrophages.

The results showed that treatment with cannabidiol was able to inhibit the synthesis of inflammatory mediators, suggesting an anti-inflammatory effect, especially after 24 hours. In addition, the substance stimulated the capacity for tooth biomineralization.

“These findings indicate that cannabidiol may be a promising bioactive substance for tissue repair in inflammatory contexts, which opens up new perspectives for its use in dental treatments, especially in regenerative dentistry, benefiting patients in different clinical situations,” says Paula-Silva.
    
According to the researcher, these findings show that cannabidiol deserves further investigation in order to establish its effective role in dental practice, as research is still in its early stages. Therefore, translating experimental results into clinical applications requires a long process of evaluation and validation.

To this end, it is essential to conduct clinical trials that assess efficacy and safety in humans, not only to confirm the observed effects, but also to understand how the substance behaves in different clinical situations, including dosage, route of administration, and potential interactions with other treatments.

In addition, the introduction of new treatments into clinical practice must meet regulatory requirements that include independent assessments, ethics committee reviews, and health authority approvals. “The growing interest in cannabinoid-based therapies, coupled with a deeper understanding of cannabidiol’s mechanisms of action, may facilitate future clinical trials, especially as more data become available,” says Paula-Silva.

About FAPESP

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the state of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration.

Council of Canadian Academies


CCA appoints expert panel on enhancing national research infrastructure





Canada’s research infrastructure is essential to the future of science and innovation, economic prosperity, and well-being throughout the country. At the request of Innovation, Science, and Economic Development Canada, the CCA has formed an expert panel to support the federal government in optimizing Canada’s research infrastructure—from its national-scale scientific facilities to its digital platforms and collaborative networks—through evidence synthesis and strategic insights. Janet King, Chair of Polar Knowledge Canada’s Board of Directors and Vice-Chair of the Canadian Light Source’s Board of Directors, will serve as panel chair.

“A strategic understanding of Canada’s national research infrastructure is critical to meeting future challenges and opportunities,” said King. “With my fellow panelists, I look forward to assessing the strengths and weaknesses of Canada’s current research infrastructure portfolio, and international best practices in research infrastructure planning and development.”

King will lead a multidisciplinary panel of experts in economic development, science and innovation policy, intergovernmental and interdisciplinary collaboration, organizational psychology, research and development funding, research infrastructure and impacts, data governance, and more. Together, panelists will answer the following question:

How can Canada optimize its national-scale research infrastructure, encompassing large-scale facilities, digital platforms, and collaborative networks, to effectively support current and future needs?

Learn more about the CCA’s national research infrastructure assessment.

The Expert Panel on Enhancing Canada’s National Research Infrastructure:

  • Janet King (chair) Chair, Board of Directors, Polar Knowledge Canada; Vice-Chair, Board of Directors, Canadian Light Source (Ottawa, ON)
  • Andrew Applejohn, Executive Director, Programs, Polar Knowledge Canada (Yellowknife, NT)
  • Frédéric Bouchard, C.Q., FRSC, Dean, Faculty of Arts and Sciences, University of Montréal (Montréal, QC)
  • Marcela Carena, Executive Director, Perimeter Institute (Waterloo, ON)
  • Jodi Cooley, Executive Director, SNOLAB; Professor of Physics, Department of Physics, Engineering Physics & Astronomy, Queen’s University (Lively, ON)
  • Kathryn Graham, FCAHS, Professor of Research Impact Assessment, University of Calgary (Calgary, AB)
  • Janet E. Halliwell, FRSC, Principal, J.E. Halliwell Associates Inc. (Salt Spring Island, BC)
  • Natalie Harrower, Executive Director, Canadian Research Data Centre Network (CRDCN); McMaster University (Hamilton, ON)
  • Gwen Phillips, Governance Strategist, Ktunaxa Nation, BC Data Champion (Ktunaxa Nation, BC)
  • Eric Siegel, Chief Innovation Officer, Ocean Frontier Institute, Dalhousie University (Halifax, NS)
  • Guillame St-Onge, Director, Institut des sciences de la mer – Université du Québec à Rimouski; Tier I Canada Research Chair in Marine Geology (Rimouski, Québec)
  • John Womersley, Special Advisor, University of Edinburgh (Edinburgh, United Kingdom)

Expert panel members serve as individuals and do not represent the views of their organizations of affiliation or employment.

To stay up to date on the progress of this and other CCA projects, sign up for our mailing list.

 

SwRI provides rapid response to address critical aging aircraft issue



Institute researchers worked with U.S. Air Force after discovery of unexpected crack




Southwest Research Institute

T-38 Talon 

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Southwest Research Institute collaborated with the U.S. Air Force to ensure fleet safety when a large crack was unexpectedly found near the cockpit of a T-38 Talon. The Institute has been working to sustain the T-38, which was first introduced in 1961, for more than 40 years.

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Credit: United States Air Force




SAN ANTONIO — March 18, 2025 — Southwest Research Institute (SwRI) collaborated with the U.S. Air Force to ensure fleet safety after a large crack was unexpectedly found near the cockpit of a T-38 Talon. A new study describes how SwRI’s risk and damage tolerance analyses helped determine a more effective inspection schedule, allowing the Air Force to find cracks before they grow to critical size.

For several decades, SwRI has provided engineering support to the Air Force to extend the life of aircraft that have exceeded their original design life. The Institute has been working to sustain the T-38, first introduced in 1961, for more than 40 years. This activity includes using SwRI-developed models to predict crack growth to determine optimal inspection and maintenance schedules. The Air Force also uses finite element models to help predict the potential crack locations of the aircraft.

“Typically, our role involves predicting structural life and providing analysis used to help determine an inspection or repair schedule,” said SwRI Lead Engineer Laura Hunt. “In the spring of 2017, when a large, unexpected crack was found by a crew chief in a longeron, a key structural component along the aircraft’s fuselage, we were equipped for a rapid response.”

This discovery resulted in the immediate grounding of the entire T-38 fleet for visual inspections, which were completed within four days. SwRI assisted with performing risk, damage tolerance, and failure analyses.

While the crack appeared in a location that full scale fatigue tests and finite element models did not predict, SwRI responded swiftly, minimizing downtime and maintaining safety, resulting from the Institute’s prior analysis work with the T-38 and other aging aircraft.

“A new problem was identified and the entire team supporting the T-38 reacted quickly to ensure the safety of the T-38 and return it to service in a manner of days,” said David Wieland, who oversees SwRI’s Aerospace Structures Section.

Senior Research Engineer Mirella Vargas led the destructive failure analysis for the cracked T-38 longeron. This entailed photographing the as-received component at the macro scale and examining specific areas with optical and electron microscopes at the micro scale, as well as identifying factors that contributed to the cracking. This analysis uncovered an additional crack in the longeron and determined that structural fatigue, the gradual weakening and eventual failure of a material due to cyclic stresses, caused both cracks.

“With this new information, we updated the model to improve the risk analyses,” Vargas said. “Consequently, the frequency of inspections was adjusted, though not drastically changed. To maintain aircraft structural integrity, models may need periodic updates to ensure the safety and functionality of the aircraft components.”

The updated inspection schedule ensured any risk remained low, balancing safety and efficiency until the remaining longerons could be replaced.

“This experience demonstrated our ability to quickly respond to unexpected issues,” Hunt said. “It has reinforced the importance of being prepared and the need for robust analysis methods.”

The paper “T-38 failure analysis of an upper cockpit longeron for safety of flight and sustainment,” appears in the Engineering Failure Analysis journal and can be accessed at https://www.sciencedirect.com/science/article/pii/S1350630725001220.

For more information, visit https://www.swri.org/markets/defense-security/defense-aerospace-aircraft/aerospace-structures/aircraft-structural-integrity-program-asip.

 

Leafcutter ants recognize and fight pathogen even 30 days after initial contamination, study shows



Characteristics of social immune memory were observed in colonies of Atta sexdens exposed to four different pathogenic fungi. The insects increased their cleaning behavior one week and one month after initial contact, but not after 60 days.




Fundação de Amparo à Pesquisa do Estado de São Paulo

Leafcutter ants recognize and fight pathogen even 30 days after initial contamination, study shows 

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Leafcutter ants recognize the pathogen even a month after first contact. In the photo, a lemon leafcutter cleans fungus cultivated by the species

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Credit: Quimi Vidaurre Montoya/IB-UNESP





A study conducted by researchers from São Paulo State University (UNESP), in Brazil, and collaborators shows that lemon leafcutter ants (Atta sexdens) exhibit behaviors that go beyond so-called social immunity, i.e. the ability to detect pathogens and try to get rid of them for the benefit of the colony.

In an article published in the journal Proceedings of the Royal Society B, scientists report that these insects are able to recognize a pathogenic fungus they have already been exposed to – even 30 days after the initial contamination – and fight it even more intensely. To do this, they increase their cleaning behavior and recruit more workers for the activity, indicating what could be called “social immune memory”.
 
“If we think of the colony as a superorganism, these behaviors would be like the immune system. In the same way that our defense cells attack invaders, such as viruses and bacteria, the workers fight infections that could harm the colony,” explains Aryel Goes, first author of the study, carried out as part of his FAPESP master’s degree at the Institute of Biosciences (IB) of UNESP, in Rio Claro, with the support of FAPESP.
 
“What we’re showing is that the social immune system of ants can store information about previous infections with the same pathogen, a phenomenon seen in our immune cells, but which occurs at a behavioral level in ant colonies,” he adds.
 
In one of the experiments, the colonies were exposed to the same pathogen for the first time, then again after seven days, and finally after a month. This last exposure had the most intense and rapid response, with more ants involved in both cleaning themselves and the fungus they cultivate to eat.
 
Atta sexdens is a leafcutter ant, a group that has a mutualistic relationship with fungi, which they cultivate inside their colonies. The fungi, in turn, provide the ants with nutrients (read more at: agencia.fapesp.br/52936).
 
Of the four pathogens tested, two were harmful to the ants and two to the cultivated fungi. The study is part of a project supported by FAPESP and coordinated by André Rodrigues, professor at IB-UNESP.
 
In a second experiment, the researchers exposed other colonies to the pathogen, repeated the contamination after seven days, and then a third time only 60 days after the initial contact. The responses were much less intense than in the colonies re-exposed after 30 days.
 
“Unlike our immune system, which in some cases responds expressively to a specific pathogen even many years after initial exposure, ants’ social immune memory has a shorter time frame, so they need to be constantly exposed to the pathogen for the information to persist,” adds Goes, who is currently a PhD student at Ohio State University in the United States.

Specific response

In the third experiment, the researchers tested the specificity of the ants’ response. Seven days after contamination with one pathogen, they exposed the ants to another. Cleaning behavior and recruitment of other workers were less intense when this second pathogen was introduced.

The following week, the first pathogen was reapplied to the colony. The return elicited a moderate response, similar to that of the first infection, but much less intense than that of the ants that had a third contact 30 days after the first.

“One hypothesis is that the lemon leafcutter reduced its hygienic response to avoid spreading the new pathogen to the rest of the colony. This is because cleaning altruism, in which ants lick each other to get rid of pathogens, can also spread new contaminants. That’s why they would have been more careful with a second infection that was completely new to the colony,” says Rodrigues, a researcher associated with the Center for Research on Biodiversity Dynamics and Climate Change (CBioClima), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by FAPESP.

One question that the experiments may raise is whether the hygienic behavior is simply the ants’ response to an unknown substance that is not necessarily pathogenic.

To test this possibility, the researchers applied a solution that does not harm ants or fungi to five colonies as a control. The hygienic responses were the least intense of all the experiments in the 80 colonies analyzed throughout the study, showing that the ants do indeed recognize pathogens and different exposures.

One hypothesis put forward by the researchers is that the social immunity observed in the study may indicate an improvement in the efficiency of contaminant removal, with a positive effect on group survival.

Because there is no information on how these variable responses affect the ants’ survival, it is not yet possible to determine whether they actually constitute a social immune memory, but further experiments could test this possibility.

“Lemon leafcutters are adapted to open areas, so they benefit from monocultures and are a pest. Their cleaning behavior is one of the obstacles to effective biological control without the use of chemical insecticides. Understanding the social immunity of leafcutters can help to develop more effective and ecologically correct controls,” concludes Rodrigues.

About FAPESP

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the state of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration.