Category: Neurology

Categories : Neurology Pain ManagementTags :

Astronauts’ ‘Space Headaches’ may Yield Insights into Those Suffered on Earth

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Space travel and zero gravity can take a toll on the body. A new study has found that astronauts with no prior history of headaches may experience migraine and tension-type headaches during long-haul space flight, which includes more than 10 days in space. Studying this type of headache may provide new insights into the mechanisms behind headaches on Earth. The study was published in Neurology.

“Changes in gravity caused by space flight affect the function of many parts of the body, including the brain,” said study author W. P. J. van Oosterhout, MD, PhD, of Leiden University Medical Center in the Netherlands.

“The vestibular system, which affects balance and posture, has to adapt to the conflict between the signals it is expecting to receive and the actual signals it receives in the absence of normal gravity. This can lead to space motion sickness in the first week, of which headache is the most frequently reported symptom. Our study shows that headaches also occur later in space flight and could be related to an increase in pressure within the skull.”

The study involved 24 astronauts from the European Space Agency, the U.S. National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency. They were assigned to International Space Station expeditions for up to 26 weeks from November 2011 to June 2018.

Prior to the study, nine astronauts reported never having any headaches and three had a headache that interfered with daily activities in the last year.

None of them had a history of recurrent headaches or had ever been diagnosed with migraine.

Of the total participants, 22 astronauts experienced one or more episode of headache during a total of 3596 days in space for all participants. Astronauts completed health screenings and a questionnaire about their headache history before the flight.

During space flight, astronauts filled out a daily questionnaire for the first seven days and a weekly questionnaire each following week throughout their stay in the space station.

The astronauts reported 378 headaches in flight. Researchers found that 92% of astronauts experienced headaches during flight compared to just 38% of them experiencing headaches prior to flight.

Of the total headaches, 170, or 90%, were tension-type headache and 19, or 10%, were migraine. Researchers also found that headaches were of a higher intensity and more likely to be migraine-like during the first week of space flight.

During this time, 21 astronauts had one or more headaches for a total of 51 headaches – of which 39 were considered tension-type headaches and 12 were migraine-like or probable migraine.

In the three months after return to Earth, none of the astronauts reported any headaches.

“Further research is needed to unravel the underlying causes of space headache and explore how such discoveries may provide insights into headaches occurring on Earth,” said Van Oosterhout.

“Also, more effective therapies need to be developed to combat space headaches as for many astronauts this a major problem during space flights.”

This research does not prove that going into space causes headaches; it only shows an association.

A limitation of the study was that astronauts reported their own symptoms, so they may not have remembered all the information accurately.

Source: American Academy of Neurology

Categories : Neurology Substance UseTags :

Continued Cocaine Use Disrupts Communication between Major Brain Networks

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A collaborative research endeavour by scientists in the Departments of Radiology, Neurology, and Psychology and Neuroscience at the UNC School of Medicine have demonstrated the deleterious effects of chronic cocaine use on the functional networks in the brain.

Their study titled “Network Connectivity Changes Following Long-Term Cocaine Use and Abstinence,” was highlighted by the editor of Journal of Neuroscience in “This Week in The Journal.” The findings show that continued cocaine use affects how crucial neural networks communicate with one another in the brain, including the default mode network (DMN), the salience network (SN), and the lateral cortical network (LCN).

“The disrupted communication between the DMN and SN can make it harder to focus, control impulses, or feel motivated without the drug,” said Li-Ming Hsu, PhD, assistant professor of radiology and lead author on the study. “Essentially, these changes can impact how well they respond to everyday situations, making recovery and resisting cravings more challenging.”

Hsu led this project during his postdoctoral tenure at the Center for Animal MRI in the Biomedical Research Imaging Center and the Department of Neurology. The work provides new insights into the brain processes that underlie cocaine addiction and creates opportunities for the development of therapeutic approaches and the identification of an imaging marker for cocaine use disorders.

The brain operates like an orchestra, where each instrumentalist has a special role crucial for creating a coherent piece of music. Specific parts of the brain need to work together to complete a task. The DMN is active during daydreams and reflections, the SN is crucial for attentiveness, and the CEN, much like a musical conductor, plays a role in our decision-making and problem-solving.

The research was motivated by observations from human functional brain imaging studies suggesting chronic cocaine use alters connectivity within and between the major brain networks. Researchers needed a longitudinal animal model to understand the relationship between brain connectivity and the development of cocaine dependence, as well as changes during abstinence.

Researchers employed a rat model to mimic human addiction patterns, allowing the models to self-dose by nose poke. Paired with advanced neuroimaging techniques, the behavioural approach enables a deeper understanding of the brain’s adaptation to prolonged drug use and highlights how addictive substances can alter the functioning of critical brain networks.

Hsu’s research team used functional MRI scans to explore the changes in brain network dynamics on models that self-administrated cocaine. Over a period of 10 days followed by abstinence, researchers observed significant alterations in network communication, particularly between the DMN and SN.

These changes were more pronounced with increased cocaine intake over the 10 days of self-administration, suggesting a potential target for reducing cocaine cravings and aiding those in recovery. The changes in these networks’ communication could also serve as useful imaging biomarkers for cocaine addiction.

The study also offered novel insights into the anterior insular cortex (AI) and retrosplenial cortex (RSC). The former is responsible for emotional and social processing; whereas, the latter controls episodic memory, navigation, and imagining future events. Researchers noted that there was a difference in coactivity between these two regions before and after cocaine intake. This circuit could be a potential target for modulating associated behavioural changes in cocaine use disorders.

“Prior studies have demonstrated functional connectivity changes with cocaine exposure; however, the detailed longitudinal analysis of specific brain network changes, especially between the anterior insular cortex (AI) and retrosplenial cortex (RSC), before and after cocaine self-administration, and following extended abstinence, provides new insights,” said Hsu.

Source: University of North Carolina Health Care

Categories : Neurology OphthalmologyTags :

In the Fight against Brain Pathogens, the Eyes Have it

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The eyes have been called the window to the brain. It turns out they also serve as an immunological barrier that protects the organ from pathogens and even tumours, Yale researchers have found. In a new study, researchers showed that vaccines injected into the eyes of mice can help disable the herpes virus, a major cause of brain encephalitis.

To their surprise, the vaccine activates an immune response through lymphatic vessels along the optic nerve.

The results were published Feb. 28 in the journal Nature.

“There is a shared immune response between the brain and the eye,” said Eric Song, an associate research scientist and resident physician in Yale School of Medicine’s Department of Immunobiology and corresponding author of the paper.

“And the eyes provide easier access for drug therapies than the brain does.”

Wanting to explore immunological interactions between brain and eyes, the research team, which was led by Song, found that the eyes have two distinct lymphatic systems regulating immune responses in the front and rear of the eye.

After they vaccinated mice with inactivated herpes virus, the researchers found that lymphatic vessels in the optic nerve sheath at the rear of the eye protected mice not only from active herpes infections, but from bacteria and even brain tumors.

Harnessing this new biology, Song’s team is currently testing newly created drugs from his lab delivered through eye injections that may help combat macular edema, or leaky blood vessels of the retina common in people with diabetes, and glaucoma.

“These results reveal a shared lymphatic circuit able to mount a unified immune response between posterior eye and the brain, highlighting an understudied immunological feature of the eyes and opening up the potential for new therapeutic strategies in ocular and central nervous system diseases,” the authors wrote.

Source: Yale University

Categories : NeurologyTags :

During Sleep, Brain Waves Flush out Metabolic Waste

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The rhythmic waves of electric pulses produced by neurons during sleep have long fascinated science and defied explanation. Slow brain waves are associated with restful, refreshing sleep. Now, scientists have found that brain waves help flush waste out of the brain during sleep. Individual nerve cells coordinate to produce rhythmic waves that propel fluid through dense brain tissue, washing the tissue in the process. This finding could help lead to new ways to treat diseases such as Alzheimer’s.

“These neurons are miniature pumps. Synchronised neural activity powers fluid flow and removal of debris from the brain,” explained first author Li-Feng Jiang-Xie, PhD, a postdoctoral research associate in the Department of Pathology & Immunology. “If we can build on this process, there is the possibility of delaying or even preventing neurological diseases, including Alzheimer’s and Parkinson’s disease, in which excess waste – such as metabolic waste and junk proteins – accumulate in the brain and lead to neurodegeneration.”

The Washington University School of Medicine in St. Louis researchers published their findings in Nature.

In carrying out the energy-demanding tasks of the brain’s functions, brain cells consume nutrients and create metabolic waste, which must be disposed of.

“It is critical that the brain disposes of metabolic waste that can build up and contribute to neurodegenerative diseases,” said Jonathan Kipnis, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Pathology & Immunology and a BJC Investigator. Kipnis is the senior author on the paper. “We knew that sleep is a time when the brain initiates a cleaning process to flush out waste and toxins it accumulates during wakefulness. But we didn’t know how that happens. These findings might be able to point us toward strategies and potential therapies to speed up the removal of damaging waste and to remove it before it can lead to dire consequences.”

But the dense brain makes cleaning difficult. Cerebrospinal fluid surrounding the brain enters and weaves through intricate cellular webs, collecting toxic waste as it travels. Upon exiting the brain, contaminated fluid must pass through a barrier before spilling into the lymphatic vessels in the dura mater, which envelopes the brain. But what powers the movement of fluid into, through and out of the brain?

Studying the brains of sleeping mice, the researchers found that neurons drive cleaning efforts by firing electrical signals in a coordinated fashion to generate rhythmic waves in the brain, Jiang-Xie explained. They determined that such waves propel the fluid movement.

The research team silenced specific brain regions so that neurons in those regions didn’t create rhythmic waves. Without these waves, fresh cerebrospinal fluid could not flow through the silenced brain regions and trapped waste couldn’t leave the brain tissue.

“One of the reasons that we sleep is to cleanse the brain,” Kipnis said. “And if we can enhance this cleansing process, perhaps it’s possible to sleep less and remain healthy. Not everyone has the benefit of eight hours of sleep each night, and loss of sleep has an impact on health. Other studies have shown that mice that are genetically wired to sleep less have healthy brains. Could it be because they clean waste from their brains more efficiently? Could we help people living with insomnia by enhancing their brain’s cleaning abilities so they can get by on less sleep?”

Brain wave patterns change throughout sleep cycles. Of note, taller brain waves with larger amplitude move fluid with more force. The researchers are now interested in understanding why neurons fire waves with varying rhythmicity during sleep and which regions of the brain are most vulnerable to waste accumulation.

“We think the brain-cleaning process is similar to washing dishes,” neurobiologist Jiang-Xie explained. “You start, for example, with a large, slow, rhythmic wiping motion to clean soluble wastes splattered across the plate. Then you decrease the range of the motion and increase the speed of these movements to remove particularly sticky food waste on the plate. Despite the varying amplitude and rhythm of your hand movements, the overarching objective remains consistent: to remove different types of waste from dishes. Maybe the brain adjusts its cleaning method depending on the type and amount of waste.”

Source: Washington University School of Medicine

Categories : Lab Tests and Imaging NeurologyTags :

“Movies” with Colour and Music Visualise Brain Activity Data in Beautiful Detail

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Novel toolkit translates neuroimaging data into audiovisual formats to aid interpretation

Simple audiovisualisation of wide field neural activity. Adapted from Thibodeaux et al., 2024, PLOS ONE, CC-BY 4.0

Complex neuroimaging data can be explored through translation into an audiovisual format – a video with accompanying musical soundtrack – to help interpret what happens in the brain when performing certain behaviours. David Thibodeaux and colleagues at Columbia University, US, present this technique in the open-access journal PLOS ONE on February 21, 2024. Examples of these beautiful “brain movies” are included below.

Recent technological advances have made it possible for multiple components of activity in the awake brain to be recorded in real time. Scientists can now observe, for instance, what happens in a mouse’s brain when it performs specific behaviours or receives a certain stimulus. However, such research produces large quantities of data that can be difficult to intuitively explore to gain insights into the biological mechanisms behind brain activity patterns.

Prior research has shown that some brain imaging data can be translated into audible representations. Building on such approaches, Thibodeaux and colleagues developed a flexible toolkit that enables translation of different types of brain imaging data – and accompanying video recordings of lab animal behaviour – into audiovisual representations.

The researchers then demonstrated the new technique in three different experimental settings, showing how audiovisual representations can be prepared with data from various brain imaging approaches, including 2D wide-field optical mapping (WFOM) and 3D swept confocally aligned planar excitation (SCAPE) microscopy.

The toolkit was applied to previously-collected WFOM data that detected both neural activity and brain blood flow changes in mice engaging in different behaviours, such as running or grooming. Neuronal data was represented by piano sounds that struck in time with spikes in brain activity, with the volume of each note indicating magnitude of activity and its pitch indicating the location in the brain where the activity occurred. Meanwhile, blood flow data were represented by violin sounds. The piano and violin sounds, played in real time, demonstrate the coupled relationship between neuronal activity and blood flow. Viewed alongside a video of the mouse, a viewer can discern which patterns of brain activity corresponded to different behaviours.

The authors note that their toolkit is not a substitute for quantitative analysis of neuroimaging data. Nonetheless, it could help scientists screen large datasets for patterns that might otherwise have gone unnoticed and are worth further analysis.

The authors add: “Listening to and seeing representations of [brain activity] data is an immersive experience that can tap into this capacity of ours to recognise and interpret patterns (consider the online security feature that asks you to “select traffic lights in this image” – a challenge beyond most computers, but trivial for our brains)…[It] is almost impossible to watch and focus on both the time-varying [brain activity] data and the behavior video at the same time, our eyes will need to flick back and forth to see things that happen together. You generally need to continually replay clips over and over to be able to figure out what happened at a particular moment. Having an auditory representation of the data makes it much simpler to see (and hear) when things happen at the exact same time.”

  1. Audiovisualisation of neural activity from the dorsal surface of the thinned skull cortex of the awake mouse.
  2. Audiovisualisation of neural activity from the dorsal surface of the thinned skull cortex of the ketamine/xylazine anaesthetised mouse.
  3. Audiovisualisation of SCAPE microscopy data capturing calcium activity in apical dendrites in the awake mouse brain.
  4. Audiovisualisation of neural activity and blood flow from the dorsal surface of the thinned skull cortex of the awake mouse.

Video Credits: Thibodeaux et al., 2024, PLOS ONE, CC-BY 4.0

Categories : Implants and Prostheses NeurologyTags :

New Neural Prosthetic Device Can Help Restore Memory in Humans

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Source: CC0

Scientists have demonstrated the first successful use of a neural prosthetic device to recall specific memories. The findings appear online in Frontiers in Computational Neuroscience.

This groundbreaking research was derived from a 2018 study led by Robert Hampson, PhD, professor of regenerative medicine, translational neuroscience and neurology at Wake Forest University School of Medicine. That study demonstrated the successful implementation of a prosthetic system that uses a person’s own memory patterns to facilitate the brain’s ability to encode and recall memory, improving recall by as much as 37%.

In the previous study, the team’s electronic prosthetic system was based on a multi-input multi-output (MIMO) nonlinear mathematical model, and the researchers influenced the firing patterns of multiple neurons in the hippocampus, a part of the brain involved in making new memories.

In this study, researchers from Wake Forest and University of Southern California (USC) built a new model of processes that assists the hippocampus in helping people remember specific information.

When the brain tries to store or recall information such as, “I turned off the stove” or “Where did I put my car keys?” groups of cells work together in neural ensembles that activate so that the information is stored or recalled.

Using recordings of the activity of these brain cells, the researchers created a memory decoding model (MDM) which let them decode what neural activity is used to store different pieces of specific information.

The neural activity decoded by the MDM was then used to create a pattern, or code, which was used to apply neurostimulation to the hippocampus when the brain was trying to store that information.

“Here, we not only highlight an innovative technique for neurostimulation to enhance memory, but we also demonstrate that stimulating memory isn’t just limited to a general approach but can also be applied to specific information that is critical to a person,” said Brent Roeder, Ph.D., a research fellow in the department of translational neuroscience at Wake Forest University School of Medicine and the study’s corresponding author.

The team enrolled 14 adults with epilepsy who were participating in a diagnostic brain-mapping procedure that used surgically implanted electrodes placed in various parts of the brain to pinpoint the origin of their seizures.

Participants underwent all surgical procedures, post-operative monitoring and neurocognitive testing at one of the three sites participating in this study including Atrium Health Wake Forest Baptist Medical Center, Keck Hospital of USC in Los Angeles and Rancho Los Amigo National Rehabilitation Center in Downey, California.

The team delivered MDM electrical stimulation during visual recognition memory tasks to see if the stimulation could help people remember images better.

They found that when they used this electrical stimulation, there were significant changes in how well people remembered things. In about 22% of cases, there was a noticeable difference in performance.

When they looked specifically at participants with impaired memory function, who were given the stimulation on both sides of their brain, almost 40% of them showed significant changes in memory performance.

“Our goal is to create an intervention that can restore memory function that’s lost because of Alzheimer’s disease, stroke or head injury,” Roeder said.

“We found the most pronounced change occurred in people who had impaired memory.”

Roeder said he hopes the technology can be refined to help people live independently by helping them recall critical information such as whether medication has been taken or whether a door is locked.

“While much more research is needed, we know that MDM-based stimulation has the potential to be used to significantly modify memory,” Roeder said.

Source: Atrium Health Wake Forest Baptist

Categories : Cancer NeurologyTags :

Removing a Protein Lets Glioblastoma Chemo Remain Effective for Longer

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New research by the University of Sussex could help to increase life expectancy and improve treatment for glioblastoma. In the study, published in the Journal of Advanced Science, researchers have discovered that an understudied protein, called PANK4, is able to block cancer cells from responding to chemotherapeutic treatment for the highly intrusive brain cancer, glioblastoma.

Scientists at Sussex have demonstrated that if the protein is removed, cancer cells respond better to temozolomide, the main chemotherapy drug for the treatment of glioblastoma.

Prof Georgios Giamas, Professor of Cancer Cell Signalling at the University of Sussex explains: “Glioblastoma is a devastating brain cancer, and researchers are working hard to identify ways to delay progression of the disease, and tackle cell resistance to treatment. As this is the first time that PANK4 has been linked to glioblastoma, the next step is to develop a drug targeting this protein to try to reverse chemo-resistance and restore sensitivity, ensuring that patients receive the best treatment and have better outcomes.”

Glioblastoma is one of the most aggressive forms of brain cancer. Approximately 250 000 – 300 000 globally are diagnosed with it annually, with a best-case survival rate of just one to 18 months after diagnosis.

Following surgery to remove the tumour, glioblastoma patients are typically treated with radiation and the chemotherapeutic drug, temozolomide. Although patients initially respond well to the drug, the cancer cells quickly develop resistance to this treatment.

The University of Sussex scientists led an international research team to understand the possible reasons for this resistance, helping to guide future therapies to improve quality of life and increase life expectancy for those with glioblastoma.

The team identified a protein called PANK4 which, when removed from the cancer cells, can lead to the cell’s death, and saw patients better responding to temozolomide. Linked to this, the researchers found that patients expressing high levels of the PANK4 protein had lower survival rates.

Dr Viviana Vella, research fellow at the University of Sussex explains: “There are a multitude of under-investigated proteins that may hold great potential for therapeutic intervention. Our study sheds light on this understudied protein, PANK4, unveiling a protective role in temozolomide-resistant cancer cells. Ultimately, PANK4 depletion represents a vulnerability that can now be exploited to restore sensitivity to the drug and improve treatment.”

Source: University of Sussex

Categories : Lab Tests and Imaging NeurologyTags :

Visualising Multiple Sclerosis with a New MRI Procedure

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This is a pseudo-colored image of high-resolution gradient-echo MRI scan of a fixed cerebral hemisphere from a person with multiple sclerosis. Credit: Govind Bhagavatheeshwaran, Daniel Reich, National Institute of Neurological Disorders and Stroke, National Institutes of Health

A key feature of multiple sclerosis (MS) is that it causes the patient’s own immune system to attack and destroy the myelin sheaths in the central nervous system. To date, it hasn’t been possible to visualise the myelin sheaths well enough to use this information for the diagnosis and monitoring of MS.  Now researchers have developed a new magnetic resonance imaging (MRI) procedure that maps the condition of the myelin sheaths more accurately than was previously possible.

The researchers successfully tested the procedure on healthy people for the first time, and published their results in Magnetic Resonance in Medicine.

In the future, the MRI system with its special head scanner could help doctors to recognise MS at an early stage and better monitor the progression of the disease.

This technology, developed by the researchers at ETH Zurich and University of Zurich, led by Markus Weiger and Emily Baadsvik from the Institute for Biomedical Engineering, could also facilitate the development of new drugs for MS. But it doesn’t end there: the new MRI method could also be used by researchers to better visualise other solid tissue types such as connective tissue, tendons and ligaments.

Quantitative myelin maps

Conventional MRI devices capture only inaccurate, indirect images of the myelin sheaths because these devices typically work by reacting to water molecules in the body that have been stimulated by radio waves in a strong magnetic field.

But the myelin sheaths, which wrap around the nerve fibres in several layers, consist mainly of fatty tissue and proteins. That said, there is some water – known as myelin water – trapped between these layers.

Standard MRIs build their images primarily using the signals of the hydrogen atoms in this myelin water, rather than imaging the myelin sheaths directly.

The ETH researchers’ new MRI method solves this problem and measures the myelin content directly.

It puts numerical values on MRI images of the brain to show how much myelin is present in a particular area compared to other areas of the image.

A number 8, for instance, means that the myelin content at this point is only 8 percent of a maximum value of 100, which indicates a significant thinning of the myelin sheaths.

Essentially, the darker the area and the smaller the number in the image, the more the myelin sheaths have been reduced.

This information ought to enable doctors to better assess the severity and progression of MS.

Measuring signals within millionths of a second

It is difficult however to image the myelin sheaths directly, since the signals that the MRI triggers in the tissue are very short-lived; the signals that emanate from the myelin water last much longer.

“Put simply, the hydrogen atoms in myelin tissue move less freely than those in myelin water. That means they generate much briefer signals, which disappear again after a few microseconds,” Weiger says, adding: “And bearing in mind a microsecond is a millionth of a second, that’s a very short time indeed.” A conventional MRI scanner can’t capture these fleeting signals because it doesn’t take the measurements fast enough.

To solve this problem, the researchers used a specially customised MRI head scanner that they have developed over the past ten years together with the companies Philips and Futura.

This scanner is characterised by a particularly strong gradient in the magnetic field.

“The greater the change in magnetic field strength generated by the three scanner coils, the faster information about the position of hydrogen atoms can be recorded,” Baadsvik says.

Generating such a strong gradient calls for a strong current and a sophisticated design.

As the researchers scan only the head, the magnetic field is more contained and concentrated than with conventional devices.

In addition, the system can quickly switch from transmitting radio waves to receiving signals; the researchers and their industry partners have developed a special circuit for this purpose.

The researchers have already successfully tested their MRI procedure on tissue samples from MS patients and on two healthy individuals. Next, they want to test it on MS patients themselves. Whether the new MRI head scanner will make its way into hospitals in the future now depends on the medical industry. “We’ve shown that our process works,” Weiger says. “Now it’s up to industry partners to implement it and bring it to market.”

Source: ETH Zurich

Categories : Neurology Pain ManagementTags :

Focused Ultrasound can Shut Down Pain Centre in Brain

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Source: CC0

A new method has been developed that could non-invasively ease pain, avoiding the side effects of pain medication and the addiction problems associated with current opioid pain relievers.

This new study by Wynn Legon, assistant professor at the Fralin Biomedical Research Institute at Virginia Tech, and his team targets the insula, the location for pain reception deep within the brain. Their study, published in the journal PAIN, found that soundwaves from low-intensity focused ultrasound aimed at this spot can reduce both the perception of pain and other effects of pain, such as heart rate changes.

“This is a proof-of-principle study,” Legon said. “Can we get the focused ultrasound energy to that part of the brain, and does it do anything? Does it change the body’s reaction to a painful stimulus to reduce your perception of pain?”

Unlike ultrasound scans, focused ultrasound delivers a narrow band of sound waves to a tiny point. At high intensity, ultrasound can ablate tissue. At low-intensity, it can cause gentler, transient biological effects, such as altering nerve cell electrical activity

Neuroscientists have long studied how non-surgical techniques, such as transcranial magnetic stimulation, might be used to treat depression and other issues. Legon’s study, however, is the first to target the insula and show that focused ultrasound can reach deep into the brain to ease pain.

The study involved 23 healthy human participants. Heat was applied to the backs of their hands to induce pain. At the same time, they wore a device that delivered focused ultrasound waves to a spot in their brain guided by magnetic resonance imaging (MRI).

Participants rated their pain perception in each application on a scale of zero to nine. Participants reported an average reduction in pain of three-fourths of a point.

“That might seem like a small amount, but once you get to a full point, it verges on being clinically meaningful,” said Legon, also an assistant professor in the School of Neuroscience in Virginia Tech’s College of Science.

“It could make a significant difference in quality of life, or being able to manage chronic pain with over-the-counter medicines instead of prescription opioids.”

Researchers also monitored each participant’s heart rate and heart rate variability as a means to discern how ultrasound to the brain also affects the body’s reaction to a painful stimulus.

The study also found the ultrasound application reduced physical responses to the stress of pain – heart rate and heart rate variability, which are associated with better overall health.

“Your heart is not a metronome. The time between your heart beats is irregular, and that’s a good thing,” Legon said.

“Increasing the body’s ability to deal with and respond to pain may be an important means of reducing disease burden.”

The effect of focused ultrasound on those factors suggests a future direction for the Legon lab’s research – to explore the heart-brain axis, or how the heart and brain influence each other, and whether pain can be mitigated by reducing its cardiovascular stress effects.

Source: Virginia Tech

Categories : Ageing NeurologyTags :

Strongest Evidence Yet of Brain’s Compensation for Cognitive Decline in Aging

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Image: Pixabay CC0

Scientists have found the strongest evidence yet that our brains can compensate for age-related deterioration by recruiting other areas to help with brain function and maintain cognitive performance.

As we age, our brain gradually atrophies, losing nerve cells and connections and this can lead to a decline in brain function. It’s not fully understood why some people appear to maintain better brain function than others, and how we can protect ourselves from cognitive decline.

A widely accepted notion is that some people’s brains are able to compensate for the deterioration in brain tissue by recruiting other areas of the brain to help perform tasks. While brain imaging studies have shown that the brain does recruit other areas, until now it has not been clear whether this makes any difference to performance on a task, or whether it provides any additional information about how to perform that task.

In a study published in the journal eLife, a team led by scientists at the University of Cambridge in collaboration with the University of Sussex have shown that when the brain recruits other areas, it improves performance specifically in the brains of older people.

Study lead Dr Kamen Tsvetanov, an Alzheimer’s Society Dementia Research Leader Fellow in the Department of Clinical Neurosciences, University of Cambridge, said: “Our ability to solve abstract problems is a sign of so-called ‘fluid intelligence’, but as we get older, this ability begins to show significant decline. Some people manage to maintain this ability better than others. We wanted to ask why that was the case – are they able to recruit other areas of the brain to overcome changes in the brain that would otherwise be detrimental?”

Brain imaging studies have shown that fluid intelligence tasks engage the ‘multiple demand network’ (MDN), a brain network involving regions both at the front and rear of the brain, but its activity decreases with age. To see whether the brain compensated for this decrease in activity, the Cambridge team looked at imaging data from 223 adults between 19 and 87 years of age who had been recruited by the Cambridge Centre for Ageing & Neuroscience (Cam-CAN).

The volunteers were asked to identify the odd-one-out in a series of puzzles of varying difficulty while lying in a functional magnetic resonance imaging (fMRI) scanner, so that the researchers could look at patterns of brain activity by measuring changes in blood flow.

As anticipated, in general the ability to solve the problems decreased with age. The MDN was particularly active, as were regions of the brain involved in processing visual information.

When the team analysed the images further using machine-learning, they found two areas of the brain that showed greater activity in the brains of older people, and also correlated with better performance on the task. These areas were the cuneus, at the rear of the brain, and a region in the frontal cortex. But of the two, only activity in the cuneus region was related to performance of the task more strongly in the older than younger volunteers, and contained extra information about the task beyond the MDN.

Although it is not clear exactly why the cuneus should be recruited for this task, the researchers point out that this brain region is usually good at helping us stay focused on what we see. Older adults often have a harder time briefly remembering information that they have just seen, like the complex puzzle pieces used in the task. The increased activity in the cuneus might reflect a change in how often older adults look at these pieces, as a strategy to make up for their poorer visual memory.

Dr Ethan Knights from the Medical Research Council Cognition and Brain Sciences Unit at Cambridge said: “Now that we’ve seen this compensation happening, we can start to ask questions about why it happens for some older people, but not others, and in some tasks, but not others. Is there something special about these people – their education or lifestyle, for example – and if so, is there a way we can intervene to help others see similar benefits?”

Dr Alexa Morcom from the University of Sussex’s School of Psychology and Sussex Neuroscience research centre said: “This new finding also hints that compensation in later life does not rely on the multiple demand network as previously assumed, but recruits areas whose function is preserved in ageing.”

The original text of this story is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Source: University of Cambridge