Category: Neurology

Categories : Gastrointestinal NeurologyTags :

Mapping the Neural Pathways for Vomiting after Eating Infected Food

On By ModernMedia
Photo by Kyle Glenn on Unsplash

The urge to vomit after eating contaminated food is the body’s natural defensive response to get rid of bacterial toxins. However, exactly how the brain initiates the response has remained a mystery. Now, researchers have mapped out the detailed neural pathway of the defensive responses from the gut to the brain in mice. The study, published in the journal Cell, could help scientists develop better anti-nausea medications for cancer patients who undergo chemotherapy.

Many foodborne bacteria produce toxins in the host after ingestion. After sensing their presence, the brain will initiate a series of biological responses, including vomit and nausea, to expel the substances and develop an aversion toward foods that taste or look the same.

“But details on how the signals are transmitted from the gut to the brain were unclear, because scientists couldn’t study the process on mice,” says Peng Cao, the paper’s corresponding author at the National Institute of Biological Sciences in Beijing. Rodents cannot vomit, so scientists have been studying vomit in other animals like dogs and cats, but these animals are not comprehensively studied and thus failed to reveal the mechanism of nausea and vomiting. However, Cao and his team noticed that while mice don’t vomit, they retch – meaning they also experience the urge to vomit without throwing up.

The team found that after receiving Staphylococcal enterotoxin A (SEA), which is a common bacterial toxin produced by Staphylococcus aureus that also leads to foodborne illnesses in humans, mice developed episodes of unusual mouth opening. Mice that received SEA opened their mouths at angles wider than those observed in the control group, where mice received saline water. Moreover, during these episodes, the diaphragm and abdominal muscles of the SEA-treated mice contract simultaneously, a pattern seen in dogs when they are vomiting. During normal breathing, animals’ diaphragm and abdominal muscles contract alternatively.

“The neural mechanism of retching is similar to that of vomiting. In this experiment, we successfully build a paradigm for studying toxin-induced retching in mice, with which we can look into the defensive responses from the brain to toxins at the molecular and cellular levels,” Cao says.

In mice treated with SEA, the team found the toxin in the intestine activates the release of serotonin, a type of neurotransmitter, by the enterochromaffin cells on the lining of the intestinal lumen. The released serotonin binds to the receptors on the vagal sensory neurons located in the intestine, which transmits the signals along the vagus nerves from the gut to a specific type of neurons in the dorsal vagal complex – Tac1+DVC neurons – in the brainstem. When Cao and his team inactivated the Tac1+DVC neurons, SEA-treated mice retched less compared with mice with normal Tac1+DVC neuron activities.

In addition, the team investigated whether chemotherapy drugs, which also induce defensive responses like nausea and vomiting in recipients, activate the same neural pathway. They injected mice with doxorubicin, a common chemotherapy drug. The drug made mice retch, but when the team inactivated their Tac1+ DVC neurons or serotonin synthesis of their enterochromaffin cells, the animals’ retching behaviours were significantly reduced.

Cao says some of the current anti-nausea medications for chemotherapy recipients, such as Granisetron, work by blocking the serotonin receptors. The study helps explain why the drug works.

“With this study, we can now better understand the molecular and cellular mechanisms of nausea and vomiting, which will help us develop better medications,” Cao says.

Next, Cao and his colleagues want to explore how toxins act on enterochromaffin cells. Preliminary research shows that enterochromaffin cells don’t sense the presence of toxins directly. The process likely involves complex immune responses of damaged cells in the intestine.

“In addition to foodborne germs, humans encounter a lot of pathogens, and our body is equipped with similar mechanisms to expel these toxic substances. For example, coughing is our body’s attempt to remove the coronavirus. It’s a new and exciting field of research about how the brain senses the existence of pathogens and initiates responses to get rid of them.” Cao says, adding that future research may reveal new and better targets for drugs, including anti-nausea medicines.

Source: ScienceDaily

Categories : NeurologyTags :

Body Self-perception is Based on The Brain’s Guesswork

On By ModernMedia
Photo by Bruce Christianson on Unsplash

Researchers at Karolinska Institutet in Sweden have found that the perception of one’s own body is largely based on the brain making guesses that are based on probability theory, instead of direct sensory input. The researchers detailed their findings in a study recently published in the journal eLife.

The researchers posit that the way humans perceive their bodies is largely governed by probability assessments based on past experiences, combined with sensory information such as sight and touch, for example.

“The experience of one’s own body is a statistical estimate of reality based on sensory information, sensory uncertainty, and previous experiences that can be summarised in a mathematical model”, explains Henrik Ehrsson, professor at the Department of Neuroscience, Karolinska Institutet.

Why are these results important?

“The results clarify the computational functions that govern the perception of one’s own body. This perception thus arises, not only as a result of a “direct” interpretation of signals from sight, touch sense, and proprioception as the textbooks say, but rather is based on active “guesses” that the brain constantly makes based on probability theory and the information that can be extracted from the patterns of sensory signals”, says Henrik Ehrsson.

“When we varied the degree of time delay between the visual and tactile impressions in small steps, or blurred the image in the augmented reality glasses to increase uncertainty, the illusion changed in a way that can be described by equations and curves: increased delay gave a weaker feeling of the rubber hand as its own, while increased uncertainty (blurriness) made the illusion stronger”, says Marie Chancel, corresponding author of the study.

Based on the experiments, the researchers came up with a statistical explanatory model for the brain’s perceptual awareness of its own body.

Changes in body ownership

The next step is to try to understand how the statistical model that determines own-bodily awareness is implemented by neural networks in the brain. In a preliminary study, the researchers have shown that neural activity in posterior parietal cortex follows the Bayesian model well in experiments where they measure brain activity with functional magnetic resonance imaging. The researchers also want to investigate how their model can explain changes in bodily awareness in various psychiatric and neurological conditions, such as Schizophrenia and Anorexia.

Source: Karolinska Institutet

Categories : Gender NeurologyTags :

Do Women Have the Edge in Remembering Words?

On By ModernMedia
Photo by Andrea Piacquadio on Pexels

Women are popularly believed at being better at finding and remembering words than men, but are the popular science textbooks which proclaim this actually correct? If so, this has relevance for tests such as measures of dementia. Researchers investigated this supposed difference, publishing their findings in Perspectives on Psychological Science.

Marco Hirnstein, professor at The University of Bergen, Norway, is unequivocal about the results. “Women are better. The female advantage is consistent across time and life span, but it is also relatively small.”

Prof Hirnstein is interested in how biological, psychological, and social factors contribute to sex/gender differences in cognitive abilities and what the underlying brain mechanisms are.

“So far, the focus has mostly been on abilities, in which men excel. However, in recent years the focus has shifted more towards women,” said Prof Hirnstein.

Textbooks and popular science books take it for granted that women are better at finding words. For example, when naming words that begin with the letter “F,” or words that belong to a certain category like animals or fruits. It has also been considered “fact” that women are better at remembering words.

Yet, the actual findings are much more inconsistent than textbooks imply: Some studies find a female advantage, some find a male advantage, some do not find any advantage.

“Most intellectual skills show no or negligible differences in average performance between men and women. However, women excel in some tasks, while men excel in others on average.”

Prof Hirnstein and his colleagues point out how their findings can be useful in diagnosis and in healthcare. The results help to clarify whether the female advantage is real but also have relevance for for interpreting the results of diagnostic assessments.

For example, to diagnose dementia, knowing that women are generally better in those tasks is critical to not under-diagnose women, due to their better average, baseline performance and not over-diagnose men. Currently, many but not all assessments take sex/gender into account.

The researchers conducted a meta-analysis of the available literatures, encompassing more than 500 measures from more than 350,000 participants. The researchers found that women are indeed better. The advantage is small but consistent across the last 50 years and across an individual’s lifespan.

Moreover, they found that the female advantage depends on the sex/gender of the leading scientist: Female scientists report a larger female advantage, male scientists report a smaller female advantage.

Source: University of Bergen

Categories : NeurologyTags :

Adult Brains can Rewire to Recover from Inherited Blindness

On By ModernMedia
Eye
Source: Daniil Kuzelev on Unsplash

A recent discovery has revealed that the adult brain has far greater potential to recover from inherited blindness than previously believed, with important implications for visually impaired people. The paper appears in Current Biology.

The research team was examining treatment for Leber congenital amaurosis (LCA), a group of inherited retinal diseases distinguished by severe visual impairment at birth. The condition, caused by mutations in any of over two dozen genes, results in degeneration or dysfunction in the retina’s photoreceptors.

Administering chemical compounds that target the retina, called synthetic retinoids, can restore a notable amount of vision in children with LCA. The UCI team wanted to find out if the treatment could make a difference for adults who have the condition.

“Frankly, we were blown away by how much the treatment rescued brain circuits involved in vision,” said corresponding author Sunil Gandhi, professor of neurobiology and behaviour. “Seeing involves more than intact and functioning retinae. It starts in the eye, which sends signals throughout the brain. It’s in the central circuits of the brain where visual perception actually arises.” Until now, scientists believed that the brain must receive those signals in childhood so that central circuits could wire themselves correctly.

The researchers were surprised by what they found in rodent models of LCA. “The central visual pathway signalling was significantly restored in adults, especially the circuits that deal with information coming from both eyes,” Prof Gandhi said. “Immediately after the treatment, the signals coming from the opposite-side eye, which is the dominant pathway in the mouse, activated two times more neurons in the brain. What was even more mind-blowing was that the signals coming from the same-side eye pathway activated five-fold more neurons in the brain after the treatment and this impressive effect was long-lasting. The restoration of visual function at the level of the brain was much greater than expected from the improvements we saw at the level of the retinae. The fact that this treatment works so well in the central visual pathway in adulthood supports a new concept, which is that there is latent potential for vision that is just waiting to be triggered.”

The finding opens exciting research possibilities. “Whenever you have a discovery that breaks with your expectations about the possibility for the brain to adapt and rewire, it teaches you a broader concept,” Prof Gandhi said. “This new paradigm could aid in the development of retinoid therapies to more completely rescue the central visual pathway of adults with this condition.”

Source: University of California – Irvine

Categories : Mental Health NeurologyTags :

Unlocking the Complex Neurological Puzzle of Depression

On By ModernMedia
Source: Pixabay

By studying the brains of fruit flies, which share similar mechanisms to human ones, scientists at Johannes Gutenberg University Mainz (JGU) are attempting to gain a better understanding of depression-like states and thus improve means of treating them. Their findings include the effect of Asian traditional medicine and its mode of preparation, and the effect of timing, such as getting a reward in the evening as opposed to other times of the day. The results were published recently in the journal Current Biology.

One aspect of their research “We have been looking at the effects of natural substances used in traditional Asian medicine, such as in Ayurveda, in our Drosophila fly model,” explained Professor Roland Strauss at JGU. “Some of these could have an anti-depressive potential or prophylactically strengthen resilience to chronic stress, so that a depression-like state might not even develop.”

The researchers intend to demonstrate efficacy, find optimal formulations, and isolate the active substances from the plant, which could lead to new drugs.

“In the Drosophila model we can pinpoint exactly where these substances are active because we are able to analyse the entire signalling chain,” Strauss pointed out. “Furthermore, every stage in the signalling pathway can also be proven.” The researchers subject the flies to a mild form of recurrent stress, such as irregular phases of vibration of the substrate. This treatment results in the development of a depression-like state (DLS) in the flies, ie, they move more slowly, do not stop to examine unexpectedly encountered sugar, and, unlike their more relaxed counterparts, are less willing to climb wide gaps. Whether or not the natural substances have an effect depends on the preparation of each natural substance, eg, whether it has been extracted with water or alcohol.

The research team has also discovered that if they reward the flies for 30 minutes on the evening of a stressful day, by offering them food with a higher sugar content than usual, or by activating the reward signalling pathway, this can prevent DLS developing. Flies have sugar receptors on their tarsi (the lower part of their legs) and their proboscis, while the end of the signalling pathway at which serotonin is released onto the mushroom body (equivalent to the human hippocampus) have also been located.

The researchers’ investigations showed that the pathway was considerably more complex than anticipated. Three different neurotransmitter systems have to be activated until the serotonin deficiency at the mushroom body, which is present in flies in a DLS, is compensated for by reward. One of these three systems is the dopaminergic system, which also signals reward in humans. Humans might obtain a reward through something other than sugar.

Boosting resilience by preventing depression

In addition, the researchers decided to look for resilience factors in the fly genome. The team intends to find out whether and how the genomes of flies that are able to better cope with stress differ from those that develop a DLS in response to exposure to recurrent mild stress. The hope is that in the future it will be possible to diagnose genetic susceptibility to depression in humans – and then treat this with the natural substances that are also being investigated during the project.

Source: Johannes Gutenberg Universitaet Mainz

Categories : NeurologyTags :

Algorithm Rapidly Assesses Level of Consciousness in ICU Patients

On By ModernMedia
Source: Pixabay CC0

Neurological assessment of an ICU patient’s level of consciousness is an important but time-consuming task that may take up to an hour. Now, researchers have developed an algorithm that can accurately track patients’ level of consciousness based on simple physiological markers that are already routinely monitored in hospital settings.

The work, published in Neurocritical Care, may eventually yield a way to reduce the strain on medical staff, and could also provide vital new data to guide clinical decisions and enable the development of new treatments.

“Consciousness isn’t a light switch that’s either on or off – it’s more like a dimmer switch, with degrees of consciousness that change over the course of the day,” said Associate Prof Samantha Kleinberg at Stevens Institute of Technology. “If you only check patients once per day, you just get one data point. With our algorithm, you could track consciousness continuously, giving you a far clearer picture.”

To develop their algorithm, A/Prof Kleiberg’s team gathered a variety of data, simple heart rate monitors up to sophisticated devices that measure brain temperature, and used them to forecast the results of a clinician’s assessment of a patient’s level of consciousness. Yet, even using just the simplest physiological data, the algorithm proved as accurate as a trained clinical examiner, and only slightly less accurate than more sophisticated tests such as MRI.

“That’s hugely important, because it means this tool could potentially be deployed in virtually any hospital setting – not just neurological ICUs where they have more sophisticated technology,” A/Prof Kleinberg explained. The algorithm could be installed as a simple software module on existing bedside patient-monitoring systems, she noted, making it relatively cheap and easy to roll out at scale.

Besides giving doctors better clinical information, and patients’ families a clearer idea of their loved ones’ prognosis, continuous monitoring could help to drive new research and ultimately improve patient outcomes.

“Consciousness is incredibly hard to study, and part of the reason is that there simply isn’t much data to work with,” said A/Prof Kleinberg. “Having round-the-clock data showing how patients’ consciousness changes could one day make it possible to treat these patients far more effectively.”

More work will be needed before the team’s algorithm can be rolled out in clinical settings. The team’s algorithm was trained based on data collected immediately prior to a clinician’s assessment, and further development will be needed to show that it can accurately track consciousness around the clock. Additional data will also be required to train the algorithm for use in other clinical settings such as paediatric ICUs.

A/Prof Kleinberg also hopes to improve the algorithm’s accuracy by cross-referencing different kinds of physiological data, and studying the way they coincide or lag one another over time. Some such relationships are known to correlate with consciousness, potentially making it possible to validate the algorithm’s consciousness ratings during periods when assessments by human clinicians aren’t available.

Source: Stevens Institute of Technology

Categories : Genetics NeurologyTags :

Gene Therapy Partially Restores Cone Function in Achromatopsia

On By ModernMedia
Eye
Source: Daniil Kuzelev on Unsplash

University of College London researchers have used gene therapy to partially restore the function of cone receptors in two children with achromatopsia, a rare genetic disorder which can cause partial or complete colourblindness.

The findings, published in Brain, suggest that treatment activates previously dormant communication links between the retina and the brain, thanks to the developing adolescent brain’s plastic nature.

The academically-led study has been running alongside a phase 1/2 clinical trial in children with achromatopsia, using a new way to test whether the treatment is changing the neural pathways specific to the cones.

Achromatopsia is caused by disease-causing variants to one of a few genes. As it affect the cones in the retina, are responsible for colour vision, people with achromatopsia are completely colourblind, while they also have very poor vision and photophobia. Their cone cells do not send signals to the brain, but many remain present, so researchers have been seeking to activate the dormant cells.

Lead author Dr Tessa Dekker said: “Our study is the first to directly confirm widespread speculation that gene therapy offered to children and adolescents can successfully activate the dormant cone photoreceptor pathways and evoke visual signals never previously experienced by these patients.

“We are demonstrating the potential of leveraging the plasticity of our brains, which may be particularly able to adapt to treatment effects when people are young.”

The study involved four young people with achromatopsia aged 10 to 15 years old.

The two trials, which each target a different gene implicated in achromatopsia, are testing gene therapies with the primary aim of establishing that the treatment is safe, while also testing for improved vision. Their results have not yet been fully compiled so the overall effectiveness of the treatments remains to be determined.

The accompanying academic study used a novel functional magnetic resonance imaging (fMRI) mapping approach to separate emerging post-treatment cone signals from existing rod-driven signals in patients, allowing the researchers to pinpoint any changes in visual function, after treatment, directly to the targeted cone photoreceptor system. They employed a ‘silent substitution’ technique using pairs of lights to selectively stimulate cones or rods. The researchers also had to adapt their methods to accommodate eye movements due to nystagmus, another symptom of achromatopsia. The results were compared to tests involving nine untreated patients and 28 volunteers with normal vision.

Each of the four children was treated with gene therapy in one eye, enabling doctors to compare the treatment’s effectiveness with the untreated eye.

For two of the four children, there was strong evidence for cone-mediated signals in the brain’s visual cortex coming from the treated eye, six to 14 months after treatment. Before the treatment, the patients showed no evidence of cone function on any tests. After treatment, their measures closely resembled those from normal sighted study participants.

The study participants also completed a test to distinguish between different levels of contrast. This showed there was a difference in cone-supported vision in the treated eyes in the same two children.

The researchers say they cannot confirm whether the treatment was ineffective in the other two study participants, or if there may have been treatment effects that were not picked up by the tests they used, or if effects are delayed.

Co-lead author Dr Michel Michaelides (UCL Institute of Ophthalmology and Moorfields Eye Hospital), who is also co-investigator on both clinical trials, said: “In our trials, we are testing whether providing gene therapy early in life may be most effective while the neural circuits are still developing. Our findings demonstrate unprecedented neural plasticity, offering hope that treatments could enable visual functions using signalling pathways that have been dormant for years.

“We are still analysing the results from our two clinical trials, to see whether this gene therapy can effectively improve everyday vision for people with achromatopsia. We hope that with positive results, and with further clinical trials, we could greatly improve the sight of people with inherited retinal diseases.”

Dr Dekker added: “We believe that incorporating these new tests into future clinical trials could accelerate the testing of ocular gene therapies for a range of conditions, by offering unparalleled sensitivity to treatment effects on neural processing, while also providing new and detailed insight into when and why these therapies work best.”

One of the study participants commented: “Seeing changes to my vision has been very exciting, so I’m keen to see if there are any more changes and where this treatment as a whole might lead in the future.

“It’s actually quite difficult to imagine what or just how many impacts a big improvement in my vision could have, since I’ve grown up with and become accustomed to low vision, and have adapted and overcome challenges (with a lot of support from those around me) throughout my life.”

Source: University College London

Categories : NeurologyTags :

Smartphone Use may Help with Memory Skills

On By ModernMedia
Photo by Priscilla du Preez on Unsplash

Instead of causing people to become lazy or forgetful, the use of smartphones and other digital devices could help improve memory skills, report the authors of a new study published in Journal of Experimental Psychology: General.

The research, showed that digital devices serve to aid people storing and recalling crucial information. This, in turn, frees up their memory to remember additional, less important, things.

Neuroscientists have previously expressed concerns that the overuse of technology could result in the breakdown of cognitive abilities and cause ‘digital dementia’.

The findings show that, on the contrary, using a digital device as external memory not only helps people to remember the information saved into the device, but it also helps them to remember unsaved information too.

To demonstrate this, researchers developed a memory task to be played on a touchscreen digital tablet or computer. The test was undertaken by 158 volunteers aged between 18 and 71.

Participants were shown up to 12 numbered circles on the screen, and had to remember to drag some of these to the left and some to the right. The number of circles that they remembered to drag to the correct side determined their pay at the end of the experiment. One side was designated “high value,” meaning that remembering to drag a circle to this side was worth 10 times as much money as remembering to drag a circle to the other “low value” side.

Participants performed this task 16 times. They had to use their own memory to remember on half of the trials and they were allowed to set reminders on the digital device for the other half.

The results found that participants tended to use the digital devices to store the details of the high-value circles. And, when they did so, their memory for those circles was improved by 18%. Their memory for low-value circles was also improved by 27%, even in people who had never set any reminders for low-value circles.

However, results also showed a potential cost to using reminders. When they were taken away, the participants remembered the low-value circles better than the high-value ones, showing that they had entrusted the high-value circles to their devices and then forgotten about them.

Senior author Dr Sam Gilbert said, “We wanted to explore how storing information in a digital device could influence memory abilities.

“We found that when people were allowed to use an external memory, the device helped them to remember the information they had saved into it. This was hardly surprising, but we also found that the device improved people’s memory for unsaved information as well.

“This was because using the device shifted the way that people used their memory to store high-importance versus low-importance information. When people had to remember by themselves, they used their memory capacity to remember the most important information. But when they could use the device, they saved high-importance information into the device and used their own memory for less important information instead.

“The results show that external memory tools work. Far from causing ‘digital dementia,’ using an external memory device can even improve our memory for information that we never saved. But we need to be careful that we back up the most important information. Otherwise, if a memory tool fails, we could be left with nothing but lower-importance information in our own memory.”

Source: University College London

Categories : NeurologyTags :

Why do We Struggle to Recognise the Faces of People of Other Races?

On By ModernMedia
An Asian man and two white men enjoying St. Patrick’s Day Photo by Pressmaster on Pexels

In a study published in Scientific Reports, cognitive psychologists at the believe they have discovered the answer to a 60-year-old question as to why people find it more difficult to recognise faces from visually distinct racial backgrounds than they do their own.

This phenomenon named the Other-Race Effect (ORE) was first discovered in the 1960s. Humans seem to use a variety of markers to recognise people, instead of photographically memorising their faces, which may be based on what they observe in others around them. Hair and eye colour may be used by white people to tell apart other white people since those features vary considerably in that racial group. Setting may also be important: some people might not notice that the centre man in the picture above is Asian while his friends on either side are white.

The ORE has consistently been demonstrated through the Face Inversion Effect (FIE) paradigm, where people are tested with pictures of faces presented in their usual upright orientation and inverted upside down. Such experiments have consistently shown that the FIE is larger when individuals are presented with faces from their own race as opposed to faces from other races.

The findings spurred decades of debate, and social scientists took the view that indicates less motivation for people to engage with people of other races, making a weaker memory for them. Cognitive scientists posited it is down to a lack of visual experience of other-race individuals, resulting in less perceptual expertise with other-race faces.

Now, a team in the Department of Psychology at Exeter, using direct electrical current brain stimulation, has found that the ORE would appear to be caused by a lack of cognitive visual expertise and not by social bias.

“For many years, we have debated the underpinning causes of ORE,” said Dr Ciro Civile, the projects lead researcher.

“One of the prevailing views is that it is predicated upon social motivational factors, particularly for those observers with more prejudiced racial attitudes. This report, a culmination of six years of funded research by the European Union and UK Research and Innovation, shows that when you systematically impair a person’s perceptual expertise through the application of brain stimulation, their ability to recognise faces is broadly consistent regardless of the ethnicity of that face.”

The research was conducted at the University of Exeter’s Washington Singer Laboratories, using non-invasive transcranial Direct Current Stimulation (tDCS) specifically designed to interfere with the ability to recognise upright faces. This was applied to the participants’ dorsolateral prefrontal cortex, via a pair of sponges attached to their scalp.

The team studied the responses of nearly 100 White European students to FIE tests, splitting them equally into active stimulation and sham/control groups. The first cohort received 10 minutes of tDCS while performing the face recognition task involving upright and inverted Western Caucasian and East Asian (Chinese, Japanese, Korean) faces. The second group, meanwhile, performed the same task while experiencing 30 seconds of stimulation, randomly administered throughout the 10 minutes – a level insufficient to induce any performance change.

In the control group, the size of the FIE for own-race faces was found to be almost three times larger than the one found for other-race faces confirming the robust ORE. This was mainly driven by participants showing a much better performance at recognising own-race faces in the upright orientation, compared to other-race faces – almost twice as likely to correctly identify that they had seen the face before.

In the active tDCS group, the stimulation successfully removed the perceptual expertise component for upright own-race faces and resulted in no difference being found between the size of the FIE for own versus other-race faces. And when it came to recognising faces that had been inverted, the results were roughly equal for both groups for both races, supporting the fact that people have no expertise whatsoever at seeing faces presented upside down.

“Establishing that the Other-Race Effect, as indexed by the Face Inversion Effect, is due to expertise rather than racial prejudice will help future researchers to refine what cognitive measures should and should not be used to investigate important social issues,” said Ian McLaren, Professor of Cognitive Psychology. “Our tDCS procedure developed here at Exeter can now be used to test all those situations where the debate regarding a specific phenomenon involves perceptual expertise.”

Source: University of Exeter

Categories : NeurologyTags :

Stimulating the Vagus Nerve Boosts the Brain’s Learning Centres

On By ModernMedia
Source: Pixabay

Researchers have shown a direct link between vagus nerve stimulation and its connection to the brain’s learning centres. The discovery, reported in the journal Neuron, may lead to treatments that will improve cognitive retention in both healthy and injured nervous systems.

“We concluded that there is a direct connection between the vagus nerve, the cholinergic system that regulates certain aspects of brain function, and motor cortex neurons that are essential in learning new skills,” said Cristin Welle, PhD, senior author of the paper. “This could provide hope to patients with a variety of motor and cognitive impairments, and someday help healthy individuals learn new skills faster.”

Researchers taught healthy mice a difficult task to see if it could help boost learning. Stimulating the vagus nerve during the process was found to help the mice learn the task much faster and achieve a higher performance level. This showed that vagus nerve stimulation can increase learning in a healthy nervous system.

The vagus nerve regulates internal organ functions like digestion, heart rate and respiration, as well as helping control reflex actions like coughing and sneezing.

The study also revealed a direct connection between the vagus nerve and the cholinergic system, which is essential for learning and attention. Each time the vagus nerve was stimulated, researchers could observe the neurons that control learning activated within the cholinergic system. Damage to this system has been linked to Alzheimer’s disease, Parkinson’s disease and other motor and cognitive conditions. Now that this connection has been established in healthy nervous systems, Dr Welle said it could lead to better treatment options for those whose systems have been damaged.

“The idea of being able to move the brain into a state where it’s able to learn new things is important for any disorders that have motor or cognitive impairments,” she said. “Our hope is that vagus nerve stimulation can be paired with ongoing rehabilitation in disorders for patients who are recovering from a stroke, traumatic brain injury, PTSD or a number of other conditions.”

In addition to the study, Dr Welle and her team have applied for a grant that would allow them to use a non-invasive device to stimulate the vagus nerve to treat patients with multiple sclerosis who have developed movement deficits. She also hopes that this device could eventually help speed up skill learning in healthy people.

“I think there’s a huge untapped potential for using vagus nerve stimulation to help the brain heal itself,” she said. “By continuing to investigate it, we can ultimately optimise patient recovery and open new doors for learning.”

Source: University of Colorado Anschutz Medical Campus