Connect with us

TOP SCEINCE

How a racing heart may alter decision-making brain circuits: Body-state monitoring neurons can hijack the decision-making process

Published

on

How a racing heart may alter decision-making brain circuits: Body-state monitoring neurons can hijack the decision-making process

Anxiety, addiction, and other psychiatric disorders are often characterized by intense states of what scientists call arousal: The heart races, blood pressure readings rise, breaths shorten, and “bad” decisions are made. In an effort to understand how these states influence the brain’s decision-making processes, scientists at the Icahn School of Medicine at Mount Sinai analyzed the data from a previous study of non-human primates. They found that two of the brain’s decision-making centers contain neurons that may exclusively monitor the body’s internal dynamics. Furthermore, a heightened state of arousal appeared to rewire one of the centers by turning some decision-making neurons into internal state monitors.

“Our results suggest that the brain’s decision-making circuits may be wired to constantly monitor and integrate what is happening inside the body. Because of that, changes in our level of arousal can alter the way that these circuits work,” said Peter Rudebeck, PhD, Associate Professor in the Nash Family Department of Neuroscience and Friedman Brain Institute at Mount Sinai and the senior author of the study published in PNAS (Proceedings of the National Academy of Sciences). “We hope that these results will help researchers gain a better understanding of the brain areas and fundamental cellular processes that underlie several psychiatric disorders.”

The study was led by Atsushi Fujimoto, MD, PhD, an Instructor in Dr. Rudebeck’s lab who previously studied how the brain controls risk-taking.

For years scientists have described the relationship between arousal and decision-making performance as a “U-shaped curve.” Basically, a little of bit of arousal — such as that experienced after a cup of coffee — might produce peak performance. But too much or too little arousal increases the chances that the brain will make slow or incorrect decisions.

Initial results from this study supported this idea. The researchers analyzed data from a previous set of experiments that tested the ability of three rhesus monkeys to decide between receiving two rewards: either a lot of tasty juice or a little. Dr. Rudebeck performed these experiments while working as a post-doctoral fellow at the National Institute of Mental Health. As expected, the monkeys consistently chose to have more juice, and on average they made this decision faster when their hearts were beating faster, supporting the idea that an aroused state fosters better performance.

Next, the researchers analyzed the electrical activity recorded from neurons in two of the brain’s decision centers called the orbitofrontal cortex and dorsal anterior cingulate cortex.

They found that the activity of about a sixth of the neurons in either area correlated with fluctuations in heart rate. In other words, if an animal’s heart rate changed, then the activity of these cells would also change by either speeding up or slowing down. This activity appeared to be unaffected by the decisions made about the different rewards that the monkeys were receiving. Meanwhile, the activity of the remaining cells in each area appeared to be primarily involved in the decision-making process.

“Brain scanning studies have suggested that bodily arousal alters the activity of these decision-making centers. Our results both support this idea on a cellular level and suggest that the sole job of some these neurons is to track the body’s internal, or interoceptive, states,” Dr. Fujimoto said. “The next question we had was: ‘What might happen during the type of heightened arousal states seen in patients who suffer from anxiety, addiction, and other psychiatric disorders?'”

To answer the question, the researchers analyzed the data obtained after the amygdala, the brain’s emotional center, was surgically turned off in each animal. This raised heart rates by up to 15 beats per minute. Now, in this higher arousal state, the faster the animals’ hearts beat, the slower they were to choose a reward. This suggests that when the animals’ arousal state was heightened, it actually hampered the decision-making process.

When the team looked at the neural activity, they found something even more interesting. The heightened arousal state appeared to alter the roles that the neurons played during decision-making. In both brain centers, the researchers saw evidence of a decrease in the number of neurons involved in the decision-making process. Moreover, in the dorsal anterior cingulate cortex, the number of neurons that appeared to track internal states rose slightly. This altered the balance of information represented in this area, as if the neural signals for decision making were “hijacked” by arousal.

“Although not definitive, our results suggest that a heightened arousal state degrades and takes control of the decision-making circuits in the brain,” Dr. Rudebeck said. “We plan to continue studying how arousal can influence higher brain functions and how this contributes to psychiatric disorders.”

This study was supported by the National Institutes of Health (MH110822), the NIH’s BRAIN Initiative (MH117040), the NIH Intramural Research Program at the National Institute of Mental Health (MH002886), the Takeda Science Foundation, and a Brain & Behavior Research Foundation Young Investigator Grant (#28979).

Source link

Continue Reading
Click to comment

Leave a Reply

TOP SCEINCE

How 3D printers can give robots a soft touch

Published

on

By

How a racing heart may alter decision-making brain circuits: Body-state monitoring neurons can hijack the decision-making process


Soft skin coverings and touch sensors have emerged as a promising feature for robots that are both safer and more intuitive for human interaction, but they are expensive and difficult to make. A recent study demonstrates that soft skin pads doubling as sensors made from thermoplastic urethane can be efficiently manufactured using 3D printers.

“Robotic hardware can involve large forces and torques, so it needs to be made quite safe if it’s going to either directly interact with humans or be used in human environments,” said project lead Joohyung Kim, a professor of electrical & computer engineering at the University of Illinois Urbana-Champaign. “It’s expected that soft skin will play an important role in this regard since it can be used for both mechanical safety compliance and tactile sensing.

As reported in the journal IEEE Transactions on Robotics, the 3D-printed pads function as both soft skin for a robotic arm and pressure-based mechanical sensors. The pads have airtight seals and connect to pressure sensors. Like a squeezed balloon, the pad deforms when it touches something, and the displaced air activates the pressure sensor.

Kim explained, “Tactile robotic sensors usually contain very complicated arrays of electronics and are quite expensive, but we have shown that functional, durable alternatives can be made very cheaply. Moreover, since it’s just a question of reprogramming a 3D printer, the same technique can be easily customized to different robotic systems.”

The researchers demonstrated that this functionality can be naturally used for safety: if the pads detect anything near a dangerous area such as a joint, the arm automatically stops. They can also be used for operational functionality with the robot interpreting touches and taps as instructions.

Since 3D-printed parts are comparatively simple and inexpensive to manufacture, they can be easily adapted to new robotic systems and replaced. Kim noted that this feature is desirable in applications where cleaning and maintaining parts is expensive or infeasible.

“Imagine you want to use soft-skinned robots to assist in a hospital setting,” he said. “They would need to be regularly sanitized, or the skin would need to be regularly replaced. Either way,there’s a huge cost. However, 3D printing is a very scalable process, so interchangeable parts can be inexpensively made and easily snapped on and off the robot body.”

Tactile inputs like the kind provided by the new pads are a relatively unexplored facet of robotic sensing and control. Kim hopes that the ease of this new manufacturing technique will inspire more interest.

“Right now, computer vision and language models are the two major ways that humans can interact with robotic systems, but there is a need for more data on physical interactions, or ‘force-level’ data,” he said. “From the robot’s point of view, this information is the most direct interaction with its environment, but there are very few users — mostly researchers — who think about this. Collecting this force-level data is a target task for me and my group.



Source link

Continue Reading

TOP SCEINCE

Honey bees experience multiple health stressors out-in-the-field

Published

on

By

How a racing heart may alter decision-making brain circuits: Body-state monitoring neurons can hijack the decision-making process


It’s not a single pesticide or virus stressing honey bees, and affecting their health, but exposure to a complex web of multiple interacting stressors encountered while at work pollinating crops, found new research out of York University.

Scientists have been unable to explain increasing colony mortality, even after decades of research examining the role of specific pesticides, parasitic mites, viruses or genetics. This led the research team to wonder if previous studies were missing something by focussing on one stressor at a time.

“Our study is the first to apply systems level or network analyses to honey bee stressors at a massive scale. I think this represents a paradigm shift in the field because we have been so focussed on finding the one big thing, the smoking gun,” says corresponding author of the new paper York Faculty of Science Professor Amro Zayed, York Research Chair in Genomics. “But we are finding that bees are exposed to a very complicated network of stressors that change quickly over time and space. It’s a level of complexity that we haven’t thought about before. To me, that’s the big surprise of this study.”

The paper, Honey bee stressor networks are complex and dependent on crop and region, published today in Current Biology, takes a much broader look at the interplay of stressors and their effects. The study team also included researchers from the University of British Columbia, Agriculture and Agri-Food Canada, the University of Victoria, the University of Lethbridge, the University of Manitoba, l’Université Laval, the University of Guelph, and the Ontario Beekeepers’ Association.

Not all stressors are the same, however. Some stressors are more influential than others — what researchers call the social media influencers of the bee world — having an outsized impact on the architecture of a highly complex network and their co-stressors. They also found that most of these influencer stressors are viruses and pesticides that regularly show up in combination with specific other stressors, compounding the negative effects through their interactions.

“Understanding which stressors co-occur and are likely to interact is profoundly important to unravelling how they are impacting the health and mortality of honey bee colonies,” says lead author, York Postdoctoral Fellow Sarah French of the Faculty of Science.

“There have been a lot of studies about major pesticides, but in this research, we also saw a lot of minor pesticides that we don’t usually think about or study. We also found a lot of viruses that beekeepers don’t typically test for or manage. Seeing the influencer stressors interact with all these other stressors, whether it be mites, other pesticides or viruses, was not only interesting, but surprising.”

French says the way influencer stressors co-occur with other stressors is similar to the way humans experience co-morbidities, such as when someone is diagnosed with heart disease. They are more likely to also have diabetes or high blood pressure or both, and each one impacts the other. “That’s similar to the way we examine bee colonies. We look at everything that’s going on in the colony and then compare or amalgamate all the colonies together to look at the broader patterns of what is happening and how everything is related. Two or multiple stressors can really synergize off each other leading to a much greater effect on bee health.”

From Québec to British Columbia, honey bee colonies were given the job of pollinating some of Canada’s most valuable crops — apples, canola oil and seed, highbush and lowbush blueberry, soybean, cranberry and corn. The study covered multiple time scales, providing numerous snapshots, rather than the usual single snapshot in time. The research team found that honey bees were exposed to an average of 23 stressors at once that combined to create 307 interactions.

Honey bees are a billion dollar industry. In 2021, honey bees contributed some $7 billion in economic value by pollinating orchards, vegetables, berries and oil seeds like canola, and produced 75 to 90 million pounds of honey. Figuring which stressors would provide the most benefit if managed would go a long way toward developing the right tools to tackle them, something beekeepers are often lacking.

The research is part of the BEECSI: ‘OMIC tools for assessing bee health project funded to the tune of $10 million by Genome Canada in 2018 to use genomic tools to develop a new health assessment and diagnosis platform powered by stressor-specific markers.

More research is needed to unravel how the stressors are interacting and impacting honey bee mortality and colony health going forward, says French. “It’s really teasing apart which of these compounds might have that relationship and how can we build off this to study those specific relationships.”

It can’t come soon enough, honey bees are currently facing poor health, colony loss, parasites, pathogens and heightened stressors worldwide. Some beekeepers in this country and the United States face a loss over winter of up to 60 per cent of their colonies.

“Our study suggests some combinations are occurring very frequently,” adds Zayed, “and that is relevant because we see them again and again, but we don’t know how these combinations affect bee health. It helps to prioritize which experiments we can now take back to the lab and establish how these interactions affect bees.”



Source link

Continue Reading

TOP SCEINCE

First evidence of human occupation in lava tube cave in Saudi Arabia

Published

on

By

How a racing heart may alter decision-making brain circuits: Body-state monitoring neurons can hijack the decision-making process


Recent strides in interdisciplinary archaeological research in Arabia have unveiled new insights into the evolution and historical development of regional human populations, as well as the dynamic patterns of cultural change, migration, and adaptation to environmental fluctuations.

Despite the challenges posed by limited preservation of archaeological assemblages and organic remains in arid environments, these discoveries are reshaping our understanding of the region’s rich cultural heritage.

One such breakthrough led by Griffith University’s Australian Research Centre for Human Evolution (ARCHE), in collaboration with international partners, comes from the exploration of underground settings, including caves and lava tubes, which have remained largely untapped reservoirs of archaeological abundance in Arabia.

Through meticulous excavation and analysis, researchers have uncovered a wealth of evidence at Umm Jirsan, spanning from the Neolithic to the Chalcolithic/Bronze Age periods (~10,000-3,500 years ago).

“Our findings at Umm Jirsan provide a rare glimpse into the lives of ancient peoples in Arabia, revealing repeated phases of human occupation and shedding light on the pastoralist activities that once thrived in this landscape,” said Dr Mathew Stewart, the lead researcher and a Research Fellow at ARCHE.

“This site likely served as a crucial waypoint along pastoral routes, linking key oases and facilitating cultural exchange and trade.”

Rock art and faunal records attest to the pastoralist use of the lava tube and surrounding areas, painting a vivid picture of ancient lifeways.

Depictions of cattle, sheep, goat and dogs corroborate the prehistoric livestock practices and herd composition of the region.

Isotopic analysis of animal remains indicates that livestock primarily grazed on wild grasses and shrubs, while humans maintained a diet rich in protein, with a notable increase in the consumption of C3 plants over time, suggesting the emergence of oasis agriculture.

“While underground localities are globally significant in archaeology and Quaternary science, our research represents the first comprehensive study of its kind in Saudi Arabia,” added Professor Michael Petraglia, Director of ARCHE.

“These findings underscore the immense potential for interdisciplinary investigations in caves and lava tubes, offering a unique window into Arabia’s ancient past.”

The research at Umm Jirsan underscores the importance of collaborative, multidisciplinary approaches to archaeological inquiry and highlights the significance of Arabia’s archaeological heritage on the global stage.

Researchers involved in this study work in close partnership with the Heritage Commission, Saudi Ministry of Culture, and the Saudi Geological Survey. Additional partners include King Saud University and key institutions in the UK, the USA, and Germany.



Source link

Continue Reading

Trending

Copyright © 2017 Zox News Theme. Theme by MVP Themes, powered by WordPress.