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The Impact of High Blood Pressure on Brain Immunity

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NINDS Research on High Blood Pressure and Cognitive Decline

NINDS Research on High Blood Pressure and Cognitive Decline

by National Institute of Neurological Disorders and Stroke (NINDS) December 14, 2023

NIH-funded researchers have found that high blood pressure leads to an increase in interleukin-17 in the brain, which activates immune cells and causes cognitive decline. The discovery, made using a mouse model, points to the possibility of new treatments by targeting T cells in the brain’s protective membranes. Credit: SciTechDaily.com

An NIH-funded study in mice suggests a potential new target for treating hypertension. Research supported by National Institutes of Health The findings suggest that a response of immune system cells within the protective membrane that surrounds the brain may contribute to the cognitive decline that can occur in people with chronic hypertension. This discovery is natural neuroscience, may shed light on new ways to counter the effects of high blood pressure on cognition. This study was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the NIH. “Understanding the role of immune signaling in cognitive decline is critical,” said Dr. Roderick Corriveau, NINDS program director. “These findings provide insight into how signaling from the immune system contributes to the symptoms of cognitive decline that ultimately lead to the diagnosis of dementia.”

Global impact of hypertension and its impact on cognition

High blood pressure affects more than 1 billion people worldwide and can cause cognitive decline not only when a stroke occurs, but even when a person with high blood pressure does not have a stroke. However, efforts to control cognitive decline in people who have not had a stroke with blood pressure-lowering treatments have shown mixed results. The results of this mouse study suggest that under conditions that mimic common hypertension, immune cells around and within the brain become abnormally activated, and that this activation leads to impaired brain function. Fluorescent staining reveals an extensive vascular network of the dura mater. These blood vessels contain her T cells, which are activated in mouse models of chronic hypertension, causing a condition that can lead to dementia-like symptoms. Credit: Iadecola Lab

Research Insights: Mouse models of hypertension

Researchers led by Costantino Iadecola, MD, director and director of the Feil Family Brain and Mind Institute in New York City, used a mouse model of hypertension to investigate interleukin-17 (IL-17). It was discovered that the levels of A chemical normally released in the body, cerebrospinal fluid, and brain to activate the immune system. Previously, Dr. Iadekola’s team showed that a high-salt diet increases IL-17 in the intestine, followed by cognitive impairment. These new findings further deepen the story by showing that IL-17 is acting within the brain itself. It is also worth noting that these experiments used a different mouse model called the DOCA salt model, which more closely mimics common hypertension in humans. “This is the most realistic model of hypertension that we have at this time,” Dr. Iadecola said. “DOCA mice simulate low-renin hypertension, a type of hypertension that is common in people, especially black Americans.”

Role of IL-17 and brain macrophages

Further research has shown that when IL-17 enters the brain, it activates immune cells known as macrophages, which are responsible for activating inflammation and fighting infections. A series of experiments showed that both mice with brain macrophage deletion of IL-17 receptors and mice with brain macrophage depletion showed no effect of hypertension on cognitive function, and therefore these macrophages were not associated with the observed cognitive function. It was confirmed that this is important for the reduction of Functioning despite other hypertension symptoms. Researchers were still looking for a source of IL-17 that acts on brain macrophages. Based on previous studies, the researchers’ initial hypothesis was that the gut releases IL-17, which travels to the brain through the bloodstream. Once there, a reaction is triggered that damages the ability of the brain’s blood vessels to respond appropriately to increased brain activity. However, blocking the ability of cerebral blood vessels to respond to IL-17 only partially reversed the cognitive impairment, suggesting that another source of IL-17 is acting on the brain. Uncovering IL-17 pathways and protective barriers One clue suggests that one layer of the brain’s protective layer, known as the dura mater, contains immune T cells that secrete IL-17 and may influence mouse behavior. taken from other recent studies. Using special mice whose cells glow fluorescent green when they make IL-17, the researchers found that high blood pressure increases IL-17 in the dura mater, which is then released into the tissues. Normally, a barrier exists within the brain’s protective covering called the meninges to prevent unwanted spillage into the brain. However, in mice with experimentally induced hypertension, this barrier appears to be disrupted, allowing IL-17 to enter the cerebrospinal fluid. Two additional experiments helped confirm this hypothesis. First, drugs were used to block the migration of her T cells from the lymph nodes to the meninges. Second, antibodies were used to block the activity of her T cells within the meninges. In both cases, the hypertensive mice recovered cognitive function, suggesting that targeting hyperactive T cells may be a new therapeutic approach worth exploring. “Taken together, our data suggest that hypertension causes two distinct effects,” Dr. Iadecola said. “One is that IL-17 has an effect on blood vessels, but this seems to be relatively minor. The more prominent central effect is that IL-17 releases IL-17, which has a direct effect on immune cells in the brain. It is caused by cells in the meninges. These immune cells, activated by signaling from the meninges, affect the brain in a way that ultimately causes cognitive impairment.”

Future Research Directions

Dr. Iadekola and his team are now trying to connect the dots between activation of immune cells in the meninges and cognitive decline. Previous works by the group The researchers suggested a link between a high-salt diet, which suppresses the production of the chemical nitric oxide in brain blood vessels, and the resulting accumulation of tau, a toxic protein that forms clumps within affected neurons. Alzheimer’s disease disease. The findings also indicate suppression of nitric oxide production in cerebral blood vessels, and whether this also leads to increased tau production is currently being investigated.

Reference: “Meningeal interleukin-17-producing T cells mediate cognitive impairment in a mouse model of salt-sensitive hypertension” Monica M. Santisteban, Samantha Schaeffer, Antoine Anfray, Giuseppe Faraco, David Brea, Gang Wang, Melissa J. Sobanko , Rose Sciortino, Gianfranco Rachumi, Ali Wiseman, Rybaik Park, Joseph Anraser, Costantino Iadecola, December 4, 2023, natural neuroscience.DOI: 10.1038/s41593-023-01497-z of NINDS’ Mind Your Risks® Campaign This paper highlights the relationship between high blood pressure and brain health (including risk of stroke and dementia), particularly in Black men aged 28 to 45, and provides recommendations to prevent and reduce the impact of high blood pressure on brain health. We offer strategies. This research was funded by NINDS (NS089323, NS095441, NS123507), the Leon Levy Fellowship in Neuroscience, and the Feil Family Foundation.


Source: scitechdaily.com

AI technology capable of translating brain waves into text

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AI can decode brainwave recordings and predict words someone is reading

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A team of scientists has announced that a sensor-equipped helmet, combined with artificial intelligence, can translate a person’s thoughts into text.

In this study, participants read passages of text while wearing hats, and their brain electrical activity was recorded through the scalp. These electroencephalogram (EEG) recordings were converted to text using an AI model called DeWave.

Lin Ching Tian Researchers from Australia’s University of Technology Sydney (UTS) say the technology is non-invasive, relatively cheap and portable.

The system is far from perfect, with an accuracy of about 40%, but recent data currently under peer review shows an improvement in accuracy of more than 60%, Lin said.

In a study published in NeurIPS conference In New Orleans, Louisiana, the DeWave program does not use spoken language, but instead has participants read sentences aloud. However, in the researchers’ latest study, participants read the text silently.

Last year, the team he led was jerry tan Researchers at the University of Texas at Austin reported similar accuracy in converting thoughts into text, but used MRI scans to interpret brain activity. Using EEG is more practical because the subject does not have to remain still in the scanner.

UTS team member Charles Zhou said the DeWave model was trained by looking at many examples where brain signals matched a particular sentence.

“For example, when you think of saying ‘hello,’ your brain sends a specific signal,” Zhou says. “DeWave learns how these signals relate to the word ‘hello’ by looking at many examples of these signals for different words and sentences.”

Once DeWave had a good understanding of the brain signals, the team connected it to an open-source large-scale language model (LLM) similar to the AI ​​that powers ChatGPT.

“This LLM is like a smart writer who can craft sentences. We tell these writers to pay attention to the signals from DeWave and use that as a guide to craft their sentences. ” says Zhou.

Finally, the team trained both DeWave and a language model together to further improve their ability to write sentences based on EEG data.

Researchers predict that further improvements to the system could revolutionize communication for people who have lost language due to stroke or other conditions, and could also have applications in robotics.

craig gin from the University of Sydney said he was impressed by Lin’s team’s work. “It’s great progress,” he says.

“People have long wanted to convert brainwaves to text, and the team’s model shows amazing accuracy. A few years ago, EEG-to-text conversion was complete and utter nonsense. .”

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Source: www.newscientist.com

Miniature VR goggles revolutionizing brain research

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This diagram shows a VR setup with an “overhead threat” projected into the top field of view.Credit: Dom Pinke/Northwestern University
For the first time, the goggles allow researchers to study responses to overhead threats. northwestern university
Researchers have developed a new virtual reality (VR) goggle for mice. These tiny goggles aren’t just cute, they offer a more immersive experience for lab mice. By more faithfully simulating natural environments, researchers can more accurately and precisely study the neural circuits underlying behavior. A leap forward in VR goggles The new goggles represent a breakthrough compared to current state-of-the-art systems that simply surround a mouse with a computer or projection screen. Current systems allow the mouse to see the laboratory environment peeking out from behind the screen, but the flat nature of the screen prevents it from conveying three-dimensional (3D) depth. Another drawback was that the researchers couldn’t easily attach a screen above the mice’s heads to simulate overhead threats, such as looming birds of prey. New VR goggles avoid all of these problems. And as VR grows in popularity, the goggles could also help researchers gain new insights into how the human brain adapts and responds to repeated VR exposure. . This area is currently poorly understood. The study was published in the journal Dec. 8. neuron. This is the first time researchers have used a VR system to simulate overhead threats. A view through new miniature VR goggles.Credit: Dom Pinke/Northwestern University “For the past 15 years, we’ve been using VR systems on mice,” said Daniel Dombeck of Northwestern University, lead author of the study. “Traditionally, labs have used large computers and projection screens to surround the animals. For humans, this is like watching TV in the living room. You can still see the couch and walls. You There are cues around it that let you know you’re not in the scene. Next, consider wearing VR goggles, like the Oculus Rift, that occupy your entire field of vision, except the projected scene. They can’t see anything, and each eye projects a different scene to create depth information, which the rats lacked.” Dombeck is a professor of neurobiology in Northwestern University’s Weinberg College of Arts and Sciences. His laboratory is a leader in the development of his VR-based systems and high-resolution laser-based imaging systems for animal research. The value of VR Although researchers can observe animals in nature, it is extremely difficult to image patterns of brain activity in real time while animals interact with the real world. To overcome this challenge, the researchers integrated his VR into a laboratory setting. In these experimental settings, animals use a treadmill to move through a scene, such as a virtual maze, projected onto a screen around them. By keeping the mouse in place on a treadmill, rather than running it through a natural environment or a physical maze, neurobiologists can use tools to The brain can be observed and mapped. Ultimately, this will help researchers understand the general principles of how neural circuits activated during different behaviors encode information. “VR essentially recreates a real-life environment,” Dombeck says. “While we’ve had a lot of success with this VR system, the animals may not be as immersed as they would be in a real environment. Force the mouse to pay attention to the screen and ignore the surrounding lab.” That alone requires a lot of training.” Introduction to iMRSIV Recent advances in hardware miniaturization led Dombeck and his team to wonder if they could develop VR goggles that more closely replicate real-world environments. We created compact goggles using custom-designed lenses and a small organic light-emitting diode (OLED) display. The system, called Miniature Rodent Stereo Illumination VR (iMRSIV), consists of two lenses and two screens, one on each side of the head, that illuminate each eye individually for 3D vision. This provides each eye with a 180-degree field of view that fully immerses the mouse and excludes the surrounding environment. An artist’s interpretation of a cartoon of a mouse wearing VR goggles. Credit: @rita
Unlike VR goggles for humans, the iMRSIV (pronounced “immersive”) system does not wrap around the mouse’s head. Instead, the goggles are attached to experimental equipment and sit snugly right in front of the mouse’s face. Since the mouse runs in place on the treadmill, the goggles still cover the mouse’s field of view.
“We designed and built a custom holder for the goggles,” said John Issa, a postdoctoral fellow in Dombeck’s lab and co-first author of the study. “The entire optical display, the screen and lens, goes all the way around the mouse.” Enhance learning and engagement By mapping the brains of mice, Dombeck and his team found that the brains of mice wearing goggles activated in a manner very similar to that of freely moving animals. And in a side-by-side comparison, the researchers found that mice with goggles were able to immerse themselves in the scene much faster than mice with traditional VR systems. “We went through the same kind of training paradigm that we’ve done in the past, but the mice with the goggles learned faster,” Dombeck said. “After the first session they were already able to complete the task. They knew where to run and were looking for the right place to get the reward. We think they may not actually need as much training because they can interact with their environment in such a way.” Simulating overhead threats for the first time Next, the researchers used goggles to simulate overhead threats. This was not possible with the current system. Since the hardware for the imaging technology is already on top of the mouse, there is no place to attach a computer screen. But the skies above rats are often where animals are searching for important, sometimes life-or-death information. “The upper part of the visual field in mice is very sensitive to detecting predators from above, like in birds,” said co-first author Dom Pinke, a research specialist in Dombeck’s lab. . “It’s not a learned behavior. It’s an imprinted behavior. It’s hardwired into the mouse’s brain.” To create the looming threat, the researchers projected a dark, expanding disk onto the top of the goggles and above the mouse’s field of view. In experiments, mice ran faster and froze up when they noticed the disc. Both behaviors are common responses to overhead threats. Researchers were able to record neural activity to study these responses in detail. “In the future, we would like to investigate situations in which rats are predators rather than prey,” Issa said. “For example, we can observe brain activity while chasing a fly. This activity involves a lot of depth perception and distance estimation. Those are things we can start to capture. is.” Accessibility in neurobiological research Dombeck hopes the goggles will not only open the door to further research, but also to new researchers. He believes the goggles could make neurobiology research more accessible because they are relatively inexpensive and require less intensive laboratory preparation. “Traditional VR systems are very complex,” Dombeck says. “It’s expensive and it’s big. You need a large lab with plenty of space. Additionally, the long time it takes to train a mouse to perform a task limits the number of experiments you can perform. Although we are still working on improvements, our goggles are small, relatively inexpensive, and also very easy to use. This could make VR technology available to other labs. There is a gender.” References: “Full-field virtual reality goggles for mice” by Domonkos Pinke, John B. Issa, Gabriel A. Dara, Gergely Dobos, Daniel A. Dombeck, December 8, 2023. neuron.DOI: 10.1016/j.neuron.2023.11.019 This research “Full-field virtual reality goggles for mice” National Institutes of Health (Award Number R01-MH101297), the National Science Foundation (Award Number ECCS-1835389), the Hartwell Foundation, and the Brain and Behavioral Research Foundation. (function(d, s, id){
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Source: scitechdaily.com

“Unconscious Brain Activity and Epileptic Seizures: The Role of Sleep Brain Waves”

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A new study has found that the slow brain waves typical of sleep occur in epilepsy patients when they are awake, helping to prevent the brain from becoming more excited. These waves reduce epileptic activity while negatively impacting memory, suggesting a potential new therapeutic approach for epilepsy.

UCL researchers have found that slow brain waves commonly seen during sleep occur in epilepsy patients while they are awake, preventing seizures but affecting memory, suggesting a new potential treatment for epilepsy. are doing.
A new study led by researchers at University College London (UCL) has found that slow waves, which normally occur only in the brain during sleep, also occur when epilepsy patients are awake, and show that slow waves, which are associated with epilepsy symptoms, can also occur in the brain during sleep. It was found that there is a possibility of preventing increased excitement.

Methodology and findings

The study was published today (November 30) in the journal nature communications The National Institute for Health Research (NIHR) UCLH Biomedical Research Center also took part in conducting electroencephalogram (EEG) scans from electrodes in the brains of 25 patients with focal epilepsy (a type of epilepsy characterized by seizures originating from specific parts of the brain). was inspected. brain), they performed an associative memory task.
Electrodes were placed in the patient’s brain to localize abnormal activity and inform surgical treatment.
During the task, participants were presented with 27 pairs of images that remained on the screen for 6 seconds. The images are divided into nine groups of three, and each group contains photos of people, places, and objects. In each case, participants had to remember which images were grouped together. EEG data were recorded continuously throughout the task.
After reviewing EEG data, the researchers found that the brains of people with epilepsy produce slow waves lasting less than a second while they are awake and participating in tasks.
The occurrence of these “awakening” slow waves increased in response to increased brain excitability, reducing the influence of epileptic spikes on brain activity.
In particular, it reduces the “firing” of nerve cells, which the researchers say can prevent epileptic activity.

Implications and future research

Lead author Professor Matthew Walker (UCL Queen Square Institute of Neurology) said: “Sleep is crucial for repairing, maintaining, and resetting brain activity. When we are awake, our brains gradually become more excitable, which recovers during sleep.
“Recent research has shown that a specific form of brain activity, namely slow waves during sleep, plays an important role in these restorative functions. We believe that these ‘sleep’ slow waves , we wanted to consider whether this could occur during wakefulness in response to the abnormal increase in brain activity associated with epilepsy.
“This study reveals for the first time ‘arousal’ slow waves, a potential protective mechanism used by the brain to counter epileptic activity. This mechanism takes advantage of brain defense activity that normally occurs during sleep, but can also occur during wakefulness in epileptic patients. ”
As part of the study, the team also wanted to test whether the occurrence of “awake” slow waves had a negative impact on cognitive function.
Researchers found that during memory tasks, “awake” slow waves reduced neuronal activity, thus affecting cognitive performance and increasing the time patients needed to complete the task.
The researchers reported that for every additional slow wave per second, reaction time increased by 0.56 seconds.
Professor Walker said: “This observation suggests that the cognitive impairments experienced by epilepsy patients, particularly memory impairments, may be due in part to short-term impairments caused by these slow waves. “
The research team hopes that future studies will increase such activity as a potential new treatment for epilepsy patients.
Lead author Dr Laurent Sheibany (UCL Queen Square Institute of Neurology) said:
“Our study suggests that naturally occurring activity is utilized by the brain to offset pathological activity. However, slow waves of ‘wake’ may have no effect on memory performance. This comes at a cost because we know we give.
“From a purely neurobiological perspective, this study also supports the idea that sleep activity does not occur uniformly throughout the brain, but may occur in specific regions of the brain.”
Reference: “Awakening slow waves in focal human epilepsy affect network activity and cognition” November 29, 2023 nature communications.
DOI: 10.1038/s41467-023-42971-3
This research was funded by the Medical Research Council, Wellcome, UCLH Biomedical Research Center and the Swiss National Science Foundation.

Source: scitechdaily.com

Neuroscientists analyze brain scans of soccer fans to research passionate devotion

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Football is a great model of social belonging, promoting inclusivity, teamwork, community spirit, social change, and individual achievement. Still, collective factors may be the reason behind acts of violence and vandalism. In a new study, neuroscientists at the University of San Sebastian investigate the brain mechanisms underlying positive and negative social stimuli in soccer fans in positive and negative social scenarios.

Mendieta other. fMRI was used to measure the brain activity of fans of rival soccer teams during a match. This image shows the contrast between winning and losing in the “good fanatic’s brain.” Activities related to important victories are shown in warm colors. The blue scale represents activations associated with significant losses. This pattern is consistent with a mentalization network suggesting a pain rationalization process triggered by a losing scenario. Image credit: Mendieta other.

“Our study aims to uncover the behaviors and dynamics associated with extreme competitiveness, aggression, and social belonging within and between fans’ groups,” said the first author. Dr. Francisco Zamorano Mendietaa researcher at the University of San Sebastian.

Rivalries are deeply rooted in the history of sports, and fans can be very protective of their “home” team and favorite players.

These same fans run through a range of emotions as they watch their team succeed or fail during a game, cheering when they score or being furious at a bad call.

Soccer fans are known for their loyalty and enthusiasm for their team, especially in Europe and South America.

To gain insight into the brain mechanisms behind fan behavior, Dr. Zamorano and his colleagues recruited 43 healthy male volunteers for a functional MRI (fMRI) study.

Participants are fans of Chile’s two most popular soccer teams, which are considered arch-rivals.

They were divided into two groups: 22 supporters of one team and 21 supporters of the rival team.

They completed a survey to determine their Soccer Enthusiasm Score and underwent a psychological evaluation.

All participants received an edited version of the match containing 63 goals.

While participants watched a compilation of matches, their brain activity was measured using fMRI, a non-invasive imaging technique that detects changes in blood flow in the brain.

The fMRI results showed that fans’ brain activity changed depending on whether their team was successful or unsuccessful.

“When your team wins, the reward system in your brain is activated,” Dr. Zamorano says.

“Losing activates the mentalization network, putting fans into a reflective state, which may alleviate some of the pain of the loss.”

“We also observed that the brain hub connecting the limbic system and frontal cortex was disrupted, disrupting mechanisms that regulate cognitive control and increasing the likelihood of destructive or violent behavior. .”

The research team’s findings could shed light on social dynamics at all levels.

“People inherently crave social connection, whether it’s membership in a running club, participation in a book discussion group, or participation in a virtual forum,” Dr. Zamorano said.

“These social bonds are often formed around shared beliefs, values ​​and interests, but there can also be elements of persuasive proselytism, or ‘groupthink’; That can lead to irrational beliefs and social discord.”

“The enthusiasm we see among some sports fans can serve as a convincing example of intense emotional investment, occasional aggressive behavior, and a decline in rationality.”

“Understanding the psychology of group identification and competition sheds light on decision-making processes and social dynamics, allowing us to more fully understand how societies operate.”

Authors present their work findings this month, Radiological Society of North America (RSNA) Annual Meeting.

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Francisco Zamorano Mendieta other. Brain mechanisms underlying emotional responses in social pain. Football as a surrogate for studying fanaticism: an fMRI study. RSNA 2023

Source: www.sci.news

Unprecedented Level of Internal Structure Exposed by Groundbreaking Human Brain ‘Atlas’

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Global collaboration has led to the creation of the world’s most comprehensive primate brain atlas, consisting of 4.2 million cells. This atlas has provided insights into region-specific functions, associations with neurological diseases, and has guided future brain research and disease intervention. The project aims to explore the evolution of the human brain and discover new targets for disease treatment. The initiative, known as the “Brain Initiative Cell Census Network” project by the National Institutes of Health, has been working towards mapping the cell groups and understanding their functions for over 21 years. The recent breakthrough discovery has allowed scientists to gain a deeper understanding of the brain and the medical mysteries behind disorders such as autism and depression. The research team, led by scientists from Arizona State University, the University of Pennsylvania, the University of Washington, and the Brotman Beatty Institute, created the largest atlas of the primate brain to date. The atlas consists of profiles of over 4 million cells, providing valuable information on the evolution of human cognition and behavior, as well as the occurrence of neurological diseases. The data collected has been made publicly available for the scientific community and the general public. The research team utilized state-of-the-art single-cell techniques and analyzed gene expression and DNA regulatory regions to identify molecularly distinct brain cell types and their functional characteristics. They also investigated the genetic architecture of neurological disease risk at the cellular level. The atlas serves as a crucial resource for further research on the human brain and potential interventions for neurological diseases.

Source: scitechdaily.com