Category Archives: Neuroscience

Neuroscience

Researchers Visualize the Intricate Branching of the Nervous System – Neuroscience News

Summary: Study reveals the molecular mechanism that allows neural networks to grow and branch out.

Source: Yale

Our nervous system is composed of billions of neurons that speak to one another through their axons and dendrites. When the human brain develops, these structures branch out in a beautifully intricate yet poorly understood way that allows nerve cells to form connections and send messages throughout the body. And now, Yale researchers have discovered the molecular mechanism behind the growth of this complex system.

Their findings are published inScience Advances.

Neurons are highly branched cells, and theyre like this because each neuron makes a connection with thousands of other neurons, says Joe Howard, Ph.D., Eugene Higgins Professor of Molecular Biophysics and Biochemistry and professor of physics, and senior researcher of the study.

Were working on this branching processhow do branches form and grow? That is whats underlying the whole way thenervous systemworks.

The team studied neuronal growth in fruit flies as they matured from embryos into larvae. To visualize this process, they tagged neurons with fluorescent markers and imaged them on a spinning disk microscope. Because neurons reside just under the cuticle [outermost layer], the researchers were able to observe this process in real time in live larvae.

After imaging the neurons at different stages of development, the team was able to create time-lapse movies of the growth.

In the earliest stages of development, thesensory neuronsbegan with only two or three dendrites. But in as little as five days, they blossomed into big, tree-like structures with thousands of branches.

Analysis of dendritic tips revealed their dynamic and stochastic (randomly determined) growth, which fluctuated among growing, shrinking, and paused states.

Before our study, there was a theory thatneuronsmay be dilating and deflating like a balloon, says Sonal Shree, Ph.D., associate research scientist and lead author of the study. And we found that no, theyre not inflating like a balloon, but rather growing and branching their tips.

We found that we can completely explain neuronal growth and the overall morphology in terms of just what the tips of the cells are doing, says Sabyasachi Sutradhar, Ph.D., associate research scientist and joint lead author of the study.

This means that now we can focus on the tips, because if we can understand how they work, then we can understand how the whole shape of the cell comes about, says Howard.

There is a whole world of branching in biology, from the veins and arteries of the circulatory system to the bronchioles of the lung. Howards lab hopes that better understanding of branching at thecellular levelwill also shed light on these processes at the molecular and tissue levels.

Author: Isabella BackmanSource: YaleContact: Isabella Backman YaleImage: The image is credited to Howard Lab

Original Research: Open access.Dynamic instability of dendrite tips generates the highly branched morphologies of sensory neurons by Sonal Shree et al. Science Advances

Abstract

Dynamic instability of dendrite tips generates the highly branched morphologies of sensory neurons

The highly ramified arbors of neuronal dendrites provide the substrate for the high connectivity and computational power of the brain. Altered dendritic morphology is associated with neuronal diseases.

Many molecules have been shown to play crucial roles in shaping and maintaining dendrite morphology. However, the underlying principles by which molecular interactions generate branched morphologies are not understood.

To elucidate these principles, we visualized the growth of dendrites throughout larval development ofDrosophilasensory neurons and found that the tips of dendrites undergo dynamic instability, transitioning rapidly and stochastically between growing, shrinking, and paused states.

By incorporating these measured dynamics into an agent-based computational model, we showed that the complex and highly variable dendritic morphologies of these cells are a consequence of the stochastic dynamics of their dendrite tips.

These principles may generalize to branching of other neuronal cell types, as well as to branching at the subcellular and tissue levels.

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Neuroscience

Perceived Choice in Music Listening Is Linked to Pain Relief – Neuroscience News

Summary: People given the impression they had control over the music they heard experienced more pain relief than those who felt as though they had no control over their music exposure.

Source: PLOS

A new study explores the use of music-listening to relieve acute pain, finding that people who were given the impression that they had control over the music they heard experienced more pain relief than people who were not given such control.

Dr. Claire Howlin of Queen Mary University of London, U.K., and colleagues from University College Dublin, Ireland, present these findings inPLOS ONEon August 3, 2022.

Music listening can be used forpainrelief, especially forchronic pain, i.e., pain lasting more than 12 weeks. However, the underlying mechanisms of these benefits are unclear, especially for acute pain, i.e., pain lasting less than 12 weeks.

Basic musical features, such as tempo or energy, seem to be less important for pain relief; instead, feeling able to make decisions about the music may be key for pain relief.

However, previous work has largely focused on findings from lab-based samples that did not explore real-world, pre-existing acute pain.

To improve understanding, Howlin and colleagues asked 286 adults experiencing real-worldacute painto rate their pain before and after listening to a music track. The track was specially composed in two different versions of varying complexity.

Participants were randomly assigned to hear either the low- or high-complexity version, and some were randomly selected to be given the impression that they had some control over the musical qualities of the track, although they heard the same track regardless of their choice.

The researchers found that participants who felt they had control over the music experienced greater relief in the intensity of their pain than participants who were not given such an impression. In questionnaires, participants reported enjoying both versions of the track, but no links were found between music complexity and amount of pain relief.

Additionally, participants who engage more actively with music in theireveryday lifeexperienced even greater pain-relief benefits from having a sense of control over the track used in this study.

These findings suggest that choice and engagement with music are important for optimizing its pain-relief potential. Future research could further explore the relationship between music choice and subsequent engagement, as well as strategies for boosting engagement to improvepain relief.

The authors add: Now we know that the act of choosing music is an important part of the well-being benefits that we see frommusic listening. Its likely that people listen more closely, or more carefully when they choose themusicthemselves.

Author: Press OfficeSource: PLOSContact: Press Office PLOSImage: The image is in the public domain

Original Research: Open access.Tune out pain: Agency and active engagement predict decreases in pain intensity after music listening by Claire Howlin et al. PLOS ONE

Abstract

Tune out pain: Agency and active engagement predict decreases in pain intensity after music listening

Music is increasingly being recognised as an adjuvant treatment for pain management. Music can help to decrease the experience of both chronic and experimental pain. Cognitive agency has been identified as a specific mechanism that may mediate the analgesic benefits of music engagement however, it is unclear if this specific mechanism translates to acute pain.

Previous attempts to understand the cognitive mechanisms that underpin music analgesia have been predominantly lab-based, limiting the extent to which observed effects may apply to participants everyday lives.

Addressing these gaps, in naturalistic settings, the present study examined the degree to which cognitive agency (i.e., perceived choice in music), music features (i.e., complexity), and individual levels of musical sophistication were related to perceived pain. In an online global experiment, using a randomised between groups experimental design with two levels for choice (no choice and perceived choice) and two levels for music (high and low complexity), a sample of 286 adults experiencing acute pain reported their pain intensity and pain unpleasantness pre- and post-music listening.

A bespoke piece of music was co-created with a commercial artist to enable the manipulation of music complexity while controlling for familiarity, while facilitating an authentic music listening experience.

Overall, findings demonstrated that increased perceived control over music is associated with analgesic benefits, and that perceived choice is more important than music complexity. Highlighting the importance of listener engagement, people who reported higher levels of active engagement experienced greater decreases of pain intensity in the perceived choice condition, than those who reported lower levels of active engagement.

These findings have implications for both research and practice, emphasising the importance of facilitating freedom of choice, and sustained engagement with music throughout music listening interventions.

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Perceived Choice in Music Listening Is Linked to Pain Relief - Neuroscience News

Neuroscience

Mothers Use the Benefits of Song to Promote Infant Development – Neuroscience News

Summary: Attention-grabbing songs mothers sing to their little ones help develop emotional regulation and brain structures associated with self-regulation.

Source: University of Miami

Professor Shannon de lEtoile knows the impact of a mothers lullaby.

As a young music therapist in Colorado, de lEtoile saw that when disadvantaged mothers were encouraged to sing to their babies, they were amazed by the positive responses they received. She quickly realized that music could be a powerful tool to help mothers learn more about their infants and to build a relationship with their new child.

Soon, de lEtoile began researching the practice, called infant-directed singing, and learned its wide range of returns. Chief among them, infant-directed singing helps babies learn to regulate their emotions, which allows them to later navigate socialization, school, and the professional world, according to de lEtoile, who has spent her career studying the habit.

If a mother can sing in a way that captures the infants attention, it can help them tap into those brain structures that they need to develop for self-regulation, said de lEtoile, a board-certified music therapist and associate dean of graduate studies at the University of Miami Frost School of Music.

Yet, while singing to infants is something most mothers do naturallywithout even realizing the benefitsfor those in difficult circumstances, infant-directed singing may not be as instinctive, de lEtoile observed. She has noticed that mothers impacted by depression, domestic violence, or substance exposure may need encouragement and guidance to provide this unique form of caregiving.

Infant-directed singing is a way that mothers communicate with their babies that most infants can recognize and respond to. But to be most effective, the mother needs to be attentive and sensitive to infant cues, said de lEtoile. For some moms that may not be happening and that impacts the infant.

But because infant-directed singing is so advantageous, de lEtoile is working with the College of Arts and Sciences Department of Psychologys flagship early intervention program at theLinda Ray Intervention Centerto create a coaching program that will guide mothers in the practice.

Recently, de lEtoiles efforts received support from theGRAMMY MuseumGrant Program, a division of the National Academy of Recording Arts and Sciences. This funding will sponsor her pilot study to train mothers of infants at the center in the critical caregiving skill. The study is one of just six scientific research projects that earned funding from the organization this year.

For close to three decades, the Linda Ray Intervention Center, which serves children from birth to age 2, has been the site of some of the most cutting-edge research in the nation. That research focuses on the developmental needs of at-risk infants and how to best support mothers in building secure bonds with their children.

We want to give moms and caregivers these tools they can use, so that they can feel empowered to help their babies thrive, de lEtoile said. Building self-regulation at an early age is so important because it helps children deal with adversity. Children who dont regulate well are lacking in resilience, and they may have problems later in life, like obesity, addiction, and aggression.

De lEtoile and the centers executive director, Isabel Chica, are now in the process of identifying and training staff members at the center, who will coach mothers for a month in the most beneficial ways to sing to their infants.

The process includes watching and recording mothers as they sing to their infants and then demonstrating to these mothers how they can be sensitive to their infants emotions while singing. Mothers will be able to notice if the infant is benefiting because the baby will gaze longer at the mother and reach a contented state.

Chica believes the project is a great fit for the center.

One of our main goals is to provide families with opportunities to learn new strategies and techniques that support positive parent-child interactions, and this pilot may strengthen parenting skills as well as a parents ability to help their child self-regulate, Chica said. We believe this is a great way for healthy attachments to develop between parent and child.

As part of the study, after each mother completes the training, de lEtoile will work with the Frost Schools music engineering program to analyze recordings of the mothers voice. Ideally, the analysis will reveal changes over time in the mothers ability to modify their singing according to the infants emotions.

Videos of the babies will also be analyzed to determine engagement with the mother over time, tracked through their gaze (whether they are focused on the mother), as well as their level of comfort, revealed in the babys facial cues.

For an infant to make progress toward self-regulation, they need focused attention on the mother. And they also need to have achieved an optimal level of arousal where they are not excited, or fussy, but comfortable, she said.

The project also signals a new frontier for de lEtoile, who in the past has documented how infant-directed singing occurs naturally, in both typical and clinical populations, including mothers with post-partum depression and infants with Down syndrome. In this project, she is providing a community-based, infant-directed singing intervention and is thrilled to work with the Linda Ray Intervention Center.

For more than two years, de lEtoile has been working closely with center staff to develop the program so that it aligns with the needs of their families. The staffers will soon begin coaching some of the mothers, and both Chica and de lEtoile are eager to begin.

We want this project to have a lasting legacy and impact, not just for us to have positive outcomes but to create a model for how a program like this could be implemented in other early intervention facilities, de lEtoile said.

Author: Megan OndrizekSource: University of MiamiContact: Megan Ondrizek University of MiamiImage: The image is credited to Jenny Hudak/University of Miam

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Mothers Use the Benefits of Song to Promote Infant Development - Neuroscience News

Neuroscience

An Effective New Treatment for Chronic Back Pain Targets the Nervous System – Neuroscience News

Summary: A newly developed method called sensorimotor retraining appears to be effective at treating chronic back pain.

Source: University of Neww South Wales

People challenged with chronic back pain have been given hope with a new treatment that focuses on retraining how the back and the brain communicate, a randomised controlled trial run by researchers at UNSW Sydney and Neuroscience Research Australia (NeuRA) and several other Australian and European universities has shown.

The study, funded by the Australian National Health and Medical Research Council (NHMRC), was described today in a paper published in theJournal of the American Medical Association. The study, carried out at NeuRA, divided 276 participants into two groups: one undertook a 12-week course of sensorimotor retraining and the other received a 12-week course of sham treatments designed to control for placebo effects, which are common in low back pain trials.

Professor James McAuleyfrom UNSWsSchool of Health Sciences, andNeuRAsaid sensorimotor retraining alters how people think about their body in pain, how they process sensory information from their back and how they move their back during activities.

What we observed in our trial was a clinically meaningful effect on pain intensity and a clinically meaningful effect on disability. People were happier, they reported their backs felt better and their quality of life was better. It also looks like these effects were sustained over the long term; twice as many people were completely recovered. Very few treatments for low back pain show long-term benefits, but participants in the trial reported improved quality of life one year later.

The new treatment challenges traditional treatments for chronic back pain, such as drugs and treatments that focus on the back such as spinal manipulation, injections, surgery and spinal cord stimulators, by viewing long-standing back pain as a modifiable problem of the nervous system rather than a disc, bone or muscle problem.

If you compare the results to studies looking atopioid treatment versus placebo, the difference for that is less than one point out of 10 in pain intensity, its only short term and there is little improvement in disability. We see similar results for studies comparingmanual therapy to shamorexercise to sham, Prof. McAuley said.

This is the first new treatment of its kind for back pain which has been the number one cause of theGlobal Disability Burden for the last 30 years that has been tested against placebo.

How it works

Prof. McAuley said the treatment is based on research that showed the nervous system of people suffering from chronic back pain behaves in a different way from people who have a recent injury to the lower back.

People with back pain are often told their back is vulnerable and needs protecting. This changes how we filter and interpret information from our back and how we move our back. Over time, the back becomes less fit, and the way the back and brain communicate is disrupted in ways that seem to reinforce the notion that the back is vulnerable and needs protecting. The treatment we devised aims to break this self-sustaining cycle, he said.

ProfessorLorimer Moseley AO, Bradley Distinguished Professor at the University of South Australia said, This treatment, which includes specially designed education modules and methods and sensorimotor retraining, aims to correct the dysfunction we now know is involved in most chronic back pain and thats a disruption within the nervous system. The disruption results in two problems: a hypersensitive pain system and imprecise communication between the back and the brain.

The treatment aims to achieve three goals. The first is to align patient understanding with the latest scientific understanding about what causes chronic back pain. The second is to normalise the way the back and the brain communicate with each other, and thirdly, to gradually retrain the body and the brain back to a normal protection setting and a resumption of usual activities.

ProfessorBen Wandof Notre Dame University, the clinical director on the trial, emphasised that by using a program of sensorimotor training, patients can see that their brain and back are not communicating well, but can also experience an improvement in this communication. He said, We think this gives them confidence to pursue an approach to recovery that trains both the body and the brain.

Training the body and the brain

Traditional therapies concentrate on fixing something in your back, injecting a disc, loosening up the joints or strengthening the muscles. What makes sensorimotor retraining different, according to Prof. McAuley is that it looks at the whole system what people think about their back, how the back and brain communicate, how the back is moved, as well as the fitness of the back.

The study authors say that more research is needed to replicate these results and to test the treatment in different settings and populations. They also want to test their approach in other chronic pain states that show similar disruption within the nervous system. They are optimistic about rolling out a training package to bring this new treatment to clinics and have enlisted partner organisations to start that process.

Once the new treatment is available via trained physiotherapists, exercise physiologists and other clinicians Prof. McAuley hopes this to occur in the next six to nine months people with chronic back pain should be able to access it at a similar cost to other therapies offered by those practitioners.

Author: Lachlan GilbertSource: University of New South WalesContact: Lachlan Gilbert University of New South WalesImage: The image is in the public domain

Original Research: Closed access.Effect of Graded Sensorimotor Retraining on Pain Intensity in Patients With Chronic LowBack Pain by James McAuley et al. JAMA

Abstract

Effect of Graded Sensorimotor Retraining on Pain Intensity in Patients With Chronic LowBack Pain

Importance

The effects of altered neural processing, defined as altering neural networks responsible for perceptions of pain and function, on chronic pain remains unclear.

Objective

To estimate the effect of a graded sensorimotor retraining intervention (RESOLVE) on pain intensity in people with chronic low back pain.

Design, Setting, and Participants

This parallel, 2-group, randomized clinical trial recruited participants with chronic (>3 months) nonspecific low back pain from primary care and community settings. A total of 276 adults were randomized (in a 1:1 ratio) to the intervention or sham procedure and attention control groups delivered by clinicians at a medical research institute in Sydney, Australia. The first participant was randomized on December 10, 2015, and the last was randomized on July 25, 2019. Follow-up was completed on February 3, 2020.

Interventions

Participants randomized to the intervention group (n=138) were asked to participate in 12 weekly clinical sessions and home training designed to educate them about and assist them with movement and physical activity while experiencing lower back pain. Participants randomized to the control group (n=138) were asked to participate in 12 weekly clinical sessions and home training that required similar time as the intervention but did not focus on education, movement, and physical activity. The control group included sham laser and shortwave diathermy applied to the back and sham noninvasive brain stimulation.

Main Outcomes and Measures

The primary outcome was pain intensity at 18 weeks, measured on an 11-point numerical rating scale (range, 0 [no pain] to 10 [worst pain imaginable]) for which the between-group minimum clinically important difference is 1.0 point.

Results

Among 276 randomized patients (mean [SD] age, 46 [14.3] years; 138 [50%] women), 261 (95%) completed follow-up at 18 weeks. The mean pain intensity was 5.6 at baseline and 3.1 at 18 weeks in the intervention group and 5.8 at baseline and 4.0 at 18 weeks in the control group, with an estimated between-group mean difference at 18 weeks of 1.0 point ([95% CI, 1.5 to 0.4];P=.001), favoring the intervention group.

Conclusions and Relevance

In this randomized clinical trial conducted at a single center among patients with chronic low back pain, graded sensorimotor retraining, compared with a sham procedure and attention control, significantly improved pain intensity at 18 weeks. The improvements in pain intensity were small, and further research is needed to understand the generalizability of the findings.

Trial Registration

ANZCTR Identifier:ACTRN12615000610538

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Neuroscience

Finding the Right Memory Strategy to Slow Cognitive Decline – Neuroscience News

Summary: Study compares two forms of cognitive training used to help those with mild cognitive impairment to improve memory and learning.

Source: University of Michigan

Whats the best way to improve your memory as you age? Turns out, it depends, a new study suggests. But your fourth-grade math teacher may have been onto something with that phrase to help you remember how to work out a complicated problem: Please Excuse My Dear Aunt Sally.

A new study led by researchers from the University of Michigan and Penn State College of Medicinecompared two approaches for people with an early form of memory loss.

The two are mnemonic strategy training, which aims to connect what someone is trying to remember to something else like a word, phrase or song (such as the Dear Aunt Sally mnemonic), and spaced retrieval training, which gradually increases the amount of time between tests of remembering something.

People with mild cognitive impairment, which can but does not always lead to a later Alzheimers disease diagnosis, were better able to remember information when using one of these cognitive training approaches. However, the data, and brain scans that revealed which areas of the brain were more active, showed each activity works differently.

Our research shows that we can help people with mild cognitive impairment improve the amount of information they learn and remember; however, different cognitive training approaches engage the brain in distinct ways, said lead and corresponding authorBenjamin Hampstead, Ph.D. Hampstead is a professor of psychiatry at Michigan Medicine and the VA Ann Arbor Healthcare System.

He directs theResearch Program on Cognition and Neuromodulation Based Interventionsand leads the Clinical Core and co-leads the Neuroimaging Core at the federally fundedMichigan Alzheimers Disease Research Center.

Mnemonic strategy training increased activity in brain areas often affected by Alzheimers disease, which likely explains why this training approach helped participants remember more information and for longer, Hampstead said.

In contrast, those completing rehearsal-based training showed reduced brain activity, which suggests they were processing the information more efficiently.

Hampstead and his team worked with Krish Sathian, MBBS, Ph.D., professor and chair of Penn States Department of Neurology and director of Penn State Neuroscience Institute. Sathian noted that cognitive training approaches are likely to become increasingly important in synergy with the new pharmacological treatments on the horizon for those with neurodegenerative disorders.

Moving forward, Hampstead said researchers and clinicians can use this type of information to help identify the best-fit non-pharmacologic treatments for their patients with memory impairment.

Additional authors include Anthony Y. Stringer, Ph.D. of Emory University, and U-M team members Alexandru D. Iordan, Ph.D. and Rob Ploutz-Snyder, Ph.D.

Author: Kara GavinSource: University of MichiganContact: Kara Gavin University of MichiganImage: The image is in the public domain

Original Research: Closed access.Towards rational use of cognitive training in those with mild cognitive impairment by Benjamin Hampstead et al. Alzheimers Disease & Dementia

Abstract

Towards rational use of cognitive training in those with mild cognitive impairment

The term cognitive training includes a range of techniques that hold potential for treating cognitive impairment caused by neurologic injury and disease.

Ourcentral premiseis that these techniques differ in their mechanisms of action and therefore engage distinct brain regions (or neural networks).

We support this premise using data from a single-blind randomized-controlled trial in which patients with mild cognitive impairment were randomized to either mnemonic strategy training (MST) or spaced retrieval training (SRT) as they learned ecologically relevant object-location associations.

Both training approaches were highly effective in the short term, but MST demonstrated a clear advantage after days to weeks. MST also increased activation in and functional connectivity between frontal, temporal, and parietal regions as well as the hippocampus.

In contrast, patterns of reduced activation and functional connectivity were evident following SRT. These findings support the rational development of cognitive training techniques.

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Finding the Right Memory Strategy to Slow Cognitive Decline - Neuroscience News

Neuroscience

Making a Memory Positive or Negative – Neuroscience News

Summary: Researchers discovered a specific neurotransmitter that helps assign either positive or negative emotions to memories.

Source: Salk Institute

Researchers at the Salk Institute and colleagues have discovered the molecule in the brain responsible for associating good or bad feelings with a memory.

Their discovery, published inNatureon July 20, 2022, paves the way for a better understanding of why some people are more likely to retain negative emotions than positive onesas can occur with anxiety, depression or post-traumatic stress disorder (PTSD).

Weve basically gotten a handle on the fundamental biological process of how you can remember if something is good or bad, says senior authorKay Tye, a professor in Salks Systems Neurobiology Laboratory and a Howard Hughes Medical Institute Investigator. This is something thats core to our experience of life, and the notion that it can boil down to a single molecule is incredibly exciting.

For a human or animal to learn whether to avoid, or seek out, a particular experience again in the future, their brain must associate a positive or negative feeling, or valence with that stimulus. The brains ability to link these feelings with a memory is called valence assignment.

In 2016, Tye discovered that a group of neurons in the brains basolateral amygdala (BLA) helps assign valence when mice are learning. One set of BLA neurons was activated with positive valence, as the animals learned to associate a tone with a sweet taste. A separate set of BLA neurons was activated with negative valence, as the animals learned to associate a different tone with a bitter taste.

We found these two pathwaysanalogous to railroad tracksthat were leading to positive and negative valence, but we still didnt know what signal was acting as the switch operator to direct which track should be used at any given time, says Tye, holder of the Wylie Vale Chair.

In the new study, the researchers homed in on the importance of the signaling molecule neurotensin to these BLA neurons. They already knew that neurotensin is a neuropeptide produced by the cells associated with valence processing, but so are a few other neurotransmitters. So, they used CRISPR gene editing approaches to selectively remove the gene for neurotensin from the cellsthe first time that CRISPR has been used to isolate specific neurotransmitter function.

Without neurotensin signaling in the BLA, mice could no longer assign positive valence and didnt learn to associate the first tone with a positive stimulus. Interestingly, the absence of neurotensin did not block negative valence. The animals instead became even better at negative valence, having a stronger association between the second tone and a negative stimulus.

The findings suggest that the brains default state is to have a bias toward fearthe neurons associated with negative valence are activated until neurotensin is released, switching on the neurons associated with positive valence. From an evolutionary perspective, Tye says, this makes sense because it helps people avoid potentially dangerous situationsand it probably resonates with people who tend to find the worst in a situation.

In further experiments, Tye and her team showed that high levels of neurotensin promoted reward learning and dampened negative valence, further supporting the idea that neurotensin is responsible for positive valence.

We can actually manipulate this switch to turn on positive or negative learning, says co-first author Hao Li, a postdoctoral fellow in the Tye Lab. Ultimately, wed like to try to identify novel therapeutic targets for this pathway.

The researchers still have questions about whether levels of neurotensin can be modulated in peoples brains to treat anxiety or PTSD. They are also planning future studies to probe what other brain pathways and molecules are responsible for triggering the release of neurotensin.

Other authors of the paper were Matilde Borio, Mackenzie Lemieux, Austin Coley, Avraham Libster, Aneesh Bal, Caroline Jia, Jasmin Revanna, Kanha Batra, Kyle Fischer, Laurel Keyes, Nancy Padilla-Coreano and Romy Wichmann of Salk; Praneeth Namburi, Jacob Olson, Anna Beyeler, Gwendolyn Calhoon, Natsuko Hitora-Imamura, Ada Felix-Ortiz, Vernica de la Fuente, Vanessa Barth, Hunter King, Ehsan Izadmehr, Cody Siciliano and Ila Fiete of MIT; Xin Jin, Sourav Choudhury, Xi Shi and Feng Zhang of the Broad Institute of MIT and Harvard; Huan Wang and Yulong Li of Peking University; and Kenneth McCullough and Kerry Ressler of Harvard Medical School.

Funding: The work was supported by the JPB Foundation, PIIF, PNDRF, JFDP, Alfred P. Sloan Foundation, New York Stem Cell Foundation, Klingenstein Foundation, McKnight Foundation, Clayton Foundation, National Institutes of Health (R01-MH102441, RF1-AG047661, DP2-DK102256, DP1-AT009925, F32 MH115446-01 and K99 DA055111), the Brain and Behavior Research Foundation, MEXT (15K21744, 17H06043), the Uehara Memorial Foundation, Singleton, Leventhal and Whitaker fellowships, a fellowship from the Swiss National Science Foundation and a Fulbright scholarship.

Author: Press OfficeSource: Salk InstituteContact: Press Office Salk InstituteImage: The image is credited to Salk Institute

Original Research: Closed access.Neurotensin orchestrates valence assignment in the amygdala by Kay Tye et al. Nature

Abstract

Neurotensin orchestrates valence assignment in the amygdala

The ability to associate temporally segregated information and assign positive or negative valence to environmental cues is paramount for survival. Studies have shown that different projections from the basolateral amygdala (BLA) are potentiated following reward or punishment learning.

However, we do not yet understand how valence-specific information is routed to the BLA neurons with the appropriate downstream projections, nor do we understand how to reconcile the sub-second timescales of synaptic plasticitywith the longer timescales separating the predictive cues from their outcomes.

Here we demonstrate that neurotensin (NT)-expressing neurons in the paraventricular nucleus of the thalamus (PVT) projecting to the BLA (PVT-BLA:NT) mediate valence assignment by exerting NT concentration-dependent modulation in BLA during associative learning.

We found that optogenetic activation of the PVT-BLA:NT projection promotes reward learning, whereas PVT-BLA projection-specific knockout of the NT gene (Nts) augments punishment learning. Using genetically encoded calcium and NT sensors, we further revealed that both calcium dynamics within the PVT-BLA:NT projection and NT concentrations in the BLA are enhanced after reward learning and reduced after punishment learning.

Finally, we showed that CRISPR-mediated knockout of theNtsgene in the PVT-BLA pathway blunts BLA neural dynamics and attenuates the preference for active behavioural strategies to reward and punishment predictive cues. In sum, we have identified NT as a neuropeptide that signals valence in the BLA, and showed that NT is a critical neuromodulator that orchestrates positive and negative valence assignment in amygdala neurons by extending valence-specific plasticity to behaviourally relevant timescales.

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Making a Memory Positive or Negative - Neuroscience News

Neuroscience

Self-Reflection Linked to Improved Late-Life Cognition and Brain Health – Neuroscience News

Summary: A persons ability to self-reflect is associated with cognition and glucose metabolism later in life, a new study finds. Those who engage in more self-reflection had improved cognition, better overall brain health, and increased glucose metabolism later in life.

Source: UCL

Self-reflection is positively associated with cognition late in life as well as glucose metabolism, a marker of brain health, finds a new study led by UCL researchers.

The authors of the new study, published inNeurology, say thatolder adultswho engage inself-reflectionmay have a reduced risk ofdementia.

Lead author, Ph.D. student Harriet Demnitz-King (UCL Psychiatry), says that there is a growing body of evidence finding that positive psychological factors, such as purpose in life and conscientiousness, may reduce the risk of dementia.

Finding further ways to reduce the risk of dementia is an urgent priority, so we hope that as self-reflection capabilities can be improved upon, it could be a useful tool in helping people to stay cognitively healthy as they age.

Anyone can engage in self-reflection and potentially increase how much they self-reflect, as it is not dependent onphysical healthor socioeconomic factors.

The study used cross-sectional data (rather than reporting results of the trial interventions) from two clinical trials, Age-Well and SCD-Well, that included a total of 259 participants with mean ages of 69 and 73. They answered questions about reflective pondering, measuring how often they think about and try to understand their thoughts and feelings.

The researchers found that people who engaged more in self-reflection had better cognition and improvedglucose metabolismas shown by brain imaging. The researchers did not find any association with amyloid deposition, the build-up of harmful brain proteins linked to Alzheimers disease.

Previous research has shown that self-reflection capabilities can be improved with a recently tested psychological intervention, and the researchers say that such a program might be useful for people at risk of dementia.

Harriet Demnitz-King explained that other studies have found that a self-reflective thinking style leads to a more adaptive stress response, with evidence even showing improvements ininflammatory responsesto stress and better cardiovascular health, so this may be how self-reflection could improve our resilience againstcognitive decline.

They caution that while their findings suggest that engagement in self-reflection helps to preserve cognition, they cannot rule out that it might instead be that people with better cognition are also better able to self-reflect, and suggest that more, longitudinal research is needed to determine the direction of causation.

Senior author Dr. Natalie Marchant (UCL Psychiatry) says that with no disease-modifying treatments yet available, it is important that we find ways to prevent dementia; by finding out which factors make dementia or cognitive decline more or less likely, we may be able to develop ways to target these factors and reduce dementia risk.

Self-reflection has also been associated with other benefits, such as recovery from depression and better cardiovascular health, so even if we cannot confirm exactly how it might impact cognitive decline, there is other evidence showing its overall benefits.

Previous studies by Dr. Marchant have found that repetitive negative thinking may increase the risk of Alzheimers disease, while mindfulness may help to improve cognition in older adults.

Dr. Richard Oakley, Associate Director of Research at Alzheimers Society, commented that in this study researchers showed for the first time that self-reflectionreflecting on your own thoughts, feelings and behaviorswas linked to better brain function in areas of thebrainknown to be affected by dementia.

While more research is needed to fully understand the implications of this finding, if self-reflection does seem to have a positive effect onbrain function, theres a chance one day we could reduce the risk of dementia with psychological treatments that help people build healthy thought patterns.

The number of people living with dementia in the UK is set to rise to 1.6 million by 2040the Government committing to double dementia research funding will ensure researchers can explore every way to reduce the risk.

Author: Chris LaneSource: UCLContact: Chris Lane UCLImage: The image is in the public domain

Original Research: Closed access.Association Between Self-Reflection, Cognition, and Brain Health in Cognitively Unimpaired Older Adults by Harriet Demnitz-King et al. Neurology

Abstract

Association Between Self-Reflection, Cognition, and Brain Health in Cognitively Unimpaired Older Adults

Background and Objectives:Self-reflection (the active evaluation of ones thoughts, feelings and behaviours) can confer protection against adverse health outcomes. Its impact on markers sensitive to Alzheimers disease (AD), however, is unknown. The primary objective of this cross-sectional study was to examine the association between self-reflection and AD-sensitive markers.

Methods:This study utilised baseline data from cognitively unimpaired older adults enrolled in the Age-Well clinical trial and older adults with subjective cognitive decline from the SCD-Well clinical trial. In both cohorts, self-reflection was measured via the reflective pondering subscale of the Rumination Response Scale, global cognition assessed via the Preclinical Alzheimers Cognitive Composite 5, and a modified late-life Lifestyle-for-Brain-Health (LIBRA) index computed to assess health and lifestyle factors.

In Age-Well, glucose metabolism and amyloid deposition were quantified in AD-sensitive grey matter regions via FDG- and AV45-PET scans, respectively. Associations between self-reflection and AD-sensitive markers (global cognition, glucose metabolism, and amyloid deposition) were assessed via unadjusted and adjusted regressions. Further, we explored whether associations were independent of health and lifestyle factors. To control for multiple comparisons in Age-Well, false discovery rate correctedp-values (pFDR) are reported.

Results:A total of 134 (mean age 69.3 3.8 years, 61.9% female) Age-Well and 125 (mean age 72.6 6.9 years, 65.6% female) SCD-Well participants were included. Across unadjusted and adjusted analyses self-reflection was positively associated with global cognition in both cohorts (Age-Well: adjusted-= 0.22, 95% confidence interval [CI] 0.05-0.40,pFDR= 0.041; SCD-Well: adjusted-= 0.18,95% CI 0.03-0.33,p= 0.023) and with glucose metabolism in Age-Well after adjustment for all covariates (adjusted-= 0.29, 95% CI 0.03-0.55,pFDR= 0.041). Associations remained following additional adjustment for LIBRA but did not survive FDR correction. Self-reflection was not associated with amyloid deposition (adjusted-= 0.13, 95% CI -0.07-0.34,pFDR= 0.189).

Discussion:Self-reflection was associated with better global cognition in two independent cohorts and with higher glucose metabolism after adjustment for covariates. There was weak evidence that relationships were independent from health and lifestyle behaviours. Longitudinal and experimental studies are warranted to elucidate whether self-reflection helps preserve cognition and glucose metabolism, or whether reduced capacity to self-reflect is a harbinger of cognitive decline and glucose hypometabolism.

Trial Registration:Age-Well:NCT02977819; SCD-Well:NCT03005652

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Self-Reflection Linked to Improved Late-Life Cognition and Brain Health - Neuroscience News

Neuroscience

Psychological Traits of Violent Extremism Investigated Using New Research Tool – Neuroscience News

Summary: The newly developed Extremist Archetypes Scale includes five dimensions of extremist archetypes.

Source: PLOS

Researchers have developed and validated a new tool known as the Extremist Archetypes Scale to help distinguish different psychological traits found among people engaged in violent extremism.

Milan Obaidi and Sara Skaar of the University of Oslo, Norway, and colleagues present the tool and validation results in the open-access journalPLOS ONEon July 20.

People who join violent extremist groups may differ widely in their motivations, knowledge, personalities, and other factors. However, research into violent extremism has often neglected this variation, limiting the scope and usefulness of such research. To help address this issue, Obaidi and colleagues built on earlier research to develop a new scale that captures heterogeneity among extremists.

Their new Extremist Archetypes Scale includes five dimensions of extremist archetypes: adventurer, fellow traveler, leader, drifter and misfit. An adventurer, for instance, may be drawn to extremism out of excitement and the prospect of being a hero, while a drifter may seek group belonging.

The researchers chose to treat archetypes as dimensions in order to allow for instances in which an extremist does not fall perfectly within a single archetype and to be able to capture a persons transition into an extremist archetype.

Next, the researchers conducted several analyses to help validate the Extremist Archetypes Scale. They tested associations between peoples scores on the scale and their scores on several well-established scales that evaluate personality traits, sociopolitical attitudes, ideologies, prejudice, and ethnic identification. In addition, they validated the scales applicability across diverse instances related to gender, political orientation, age, and ethnicity.

The validation analyses supported the predictive validity of the scaleincluding across political orientation and ethnicityas well as the idea that the archetypes consistently reflect different personality and behavioral profiles.

For instance, the adventurer archetype was associated with personality traits of extraversion and violent behavioral intentions, and the misfit was associated with narcissism, Machiavellianism, and psychopathy.

The researchers suggest that application of their scale in future research could help inform counter-extremism efforts. They also note that they focused on group-based extremism, but future research could examine archetypes of extremists who act alone.

The authors add: The current research developed the Extremist Archetypes Scale, whichmeasures different archetype dimensions that reflect different motivations for joining extremist groups and obtaining different roles within them.

Author: Hanna AbdallahSource: PLOSContact: Hanna Abdallah PLOSImage: The image is in the public domain

Original Research: Open access.Measuring extremist archetypes: Scale development and validation by Milan Obaidi et al. PLOS ONE

Abstract

Measuring extremist archetypes: Scale development and validation

Previous work has often disregarded the psychological heterogeneity of violent extremists. This research aimed to contribute to a more nuanced understanding of the psychological diversity of violent extremists.

Based on qualitative work, we developed and validated the Extremist Archetypes Scale, identifying five distinct archetype dimensions: adventurer, fellow traveler, leader, drifter and misfit.

Study 1 identified five dimensions among White majority members (N= 307), four of which were related to extremist violent intentions and which dissociated in terms of sociopolitical ideologies and intergroup attitudes.

Preregistered Study 2 (N= 308) confirmed the scales five-factor solution in another sample of White majority members, replicated relationships with violent intentions, and demonstrated the dimensions distinct personality correlates.

As in Study 1, the archetype dimensions had positive associations with extremist violent intentions and tapped onto different psychological profiles in terms of major personality traits. Study 3 (N= 317) replicated these results in a sample of Muslim minority members.

Measurement equivalence was established across gender, age, political orientation, and ethnicity (majority and minority).

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Psychological Traits of Violent Extremism Investigated Using New Research Tool - Neuroscience News

Neuroscience

Neuroscience Says These 5 Simple Tricks Will Calm Your Anxiety Instantly – Inc.

Fortunately,we can point to simple techniques that neuroscience suggestswork effectively tomake people much less anxious--quicker than you think.

1. Listen to this specially designed song.

I'm putting this first because it's my favorite and I'm still shocked at how well it works.

A decade ago, British musicians teamed up with sound therapists to record a song called Weightlessnessthat stimulates specific neurological reactions: lower heart rate, lower blood pressure, and reduced levels of the stress hormone, cortisol.

"The song...contains a sustaining rhythm that starts at 60 beats per minute and gradually slows to around 50," explained Lyz Cooper, founder of the British Academy of Sound Therapy. "While listening, your heart rate gradually comes to match that beat."

It's just eight minutes long, andit works like a charm. I first tried it several years ago, and I've kept it bookmarked on my computer ever since. I'll embed a YouTube version at the end of this column.

2. Use the 4-7-8 breathing method.

Another very easy, almost too-good-to-be-true method that actually works. In short, by breathing in a very simple way, you can kick-start your parasympathetic nervous system, which causes the body to become calmer.

Repeat steps 3, 4 and 5 a total of three times. Bonus: If you're ever lying awake at night unable to sleep, the 4-7-8 method of breathing works wonders for that, too.

3. Get 45 minutes of vigorous exercise.

This one is fairly recent, and it comes from the International Journal of Environmental Research and Public Health. Researchers studied 66 college students during the pandemic, and concluded that negative thoughts and anxiety were appreciably less prevalent when participants exercised:

Choose whatever works for your ambition and schedule; I tend to recommend the 45 minute version, simply because if part of what is creating anxiety is concern about getting things done, adding a 2-hour habit to your day might be a bit self-defeating.

4. Get some nature.

We have all kinds of studies to point to here. Two of my colleagues on Inc.com have written pretty extensively about how taking an "awe walk" in nature can make people feel less anxious -- even one lasting just 15 minutes.

You don't even have to walk, necessarily; researchers found that simply commuting to work through "outdoor spaces that contain 'green' and/or 'blue' natural elements" (think trees, grass, and bodies of water) made people less anxious.

For that matter, researchers at the University of Hyogo in Japan say that simply putting small plants on workers' desks in an office "contributed to their psychological stress reduction regardless of their age or plants choice."

Bottom line, it's a lot harder to be anxious when you're surrounded by green and blue.

5. Save it for later.

This last trick is less about shutting off anxiety than it is about making it manageable. In short, make a note about the things that make you anxious -- even a literal, written note -- and then promise yourself that you'll set a block of time later in the day to be worried about them.

Seriously, pick a time and put it on your schedule: "From 2 p.m. to 2:20 p.m. is my "worry time." Any other time of day, I jot down my worries so I can feel anxious about them at the appropriate time."

"This strategy focuses on not postponing your worries," psychologist Dr. Regine Galanti explained to Time, "[instead] setting up a time where you can worry all you want. ... [I]t sets boundaries, so when a worry comes up at 9 a.m., you can say, 'Hey, not now, your time is coming.'"

Perhaps the best part about this trick? By whatever time you've set aside for worrying, you'll often find you're no longer worried.

Bonus:Train your brain

As I write in my free e-book Neuroscience: 13 Ways to Understand and Train Your Brain for Life, there's nothing more fascinating than the human brain, and the unexpected ways in which it works.

If it helps to get rid ofanxiety, that has to be at the top of the list.

Here's the embed of the 8-minute song, Weightlessness,that I promised above. I recommend watching it within this article rather than clicking out, otherwise your calming music might be jarringly interrupted by an ad.

The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.

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Neuroscience Says These 5 Simple Tricks Will Calm Your Anxiety Instantly - Inc.

Neuroscience

Making Sense of Socially Enhanced Aggression in the Brain – Neuroscience News

Summary: Study reveals the lateral habenula plays a critical role in the priming of aggression in male mice.

Source: University of Tsukuba

When male animals spend time around other males of the same species, subsequent aggressive behavior tends to be amplifiedthis type of priming is known as social instigation. However, the pathway in the brain that leads to this increased aggression was, until recently, relatively unknown.

In a study published inNature Communications, researchers from the University of Tsukuba have revealed that the lateral habenula, a small and relatively primitive region located deep within the brain, is important for this behavior in mice.

Aggressive behavior, especially between males, is important in many animal species and can be promoted in a number of different ways, including by social instigation.

Although this behavioral effect is well characterized, the brain pathway that is responsible for it is less understood.

The dorsal raphe nucleus is a brain region that controls aggressive behaviors, and it receives glutamate (a molecule that acts as a signal between brain cells) when social instigation occurs. However, the source of this glutamate was a mystery.

Researchers from the University of Tsukuba decided to address this gap in the knowledge.

Many different brain regions release glutamate into the dorsal raphe nucleus, explains lead author of the study Professor Aki Takahashi.

Because our initial experiments suggested that glutamate release from the lateral habenula might be responsible for aggression induced by social instigation, we conducted more experiments to see if this was the case.

The research team used two different techniques to block communication between the lateral habenula and dorsal raphe nucleus in mice, and found that this also blocked the increased aggression caused by social instigationbut it didnt affect normal levels of aggression, suggesting that this pathway is not important for aggressive behavior in general.

We then wanted to look at the pathway beyond the dorsal nucleus, says Professor Takahashi.

We found that social instigation caused signals to travel through the brain from the lateral habenula to the dorsal raphe nucleus and then on to the ventral tegmental areaa highly connected region in the midbrainleading to heightened aggression.

Although there are many differences in aggression between humans and mice, the results of this new study may have applications when investigating socially provoked anger or violence. There is currently a lack of effective preventative measures against socially provoked aggression, and any information that increases our understanding of these aggressive behaviors will be useful.

Funding: This research was supported by JSPS KAKENHI Grant Numbers JP17H04766, JP19H05202, JP21H00183, Japan Science and Technology Agency (JST) Adaptable and Seamless Technology transfer Program through Target-driven R&D (A-STEP) Grant Number JPMJTM20BW and JST FOREST Program Grant Number JPMJFR214A to AT, and by National Institute of Mental Health grants R01MH114882-01, R01MH104559, and R01MH127820 to SJR.

Author: YAMASHINA NaokoSource: University of TsukubaContact: YAMASHINA Naoko University of TsukubaImage: The image is in the public domain

Original Research: Open access.Lateral habenula glutamatergic neurons projecting to the dorsal raphe nucleus promote aggressive arousal in mice by TAKAHASHI Aki et al. Nature Communications

Abstract

Lateral habenula glutamatergic neurons projecting to the dorsal raphe nucleus promote aggressive arousal in mice

The dorsal raphe nucleus (DRN) is known to control aggressive behavior in mice.

Here, we found that glutamatergic projections from the lateral habenula (LHb) to the DRN were activated in male mice that experienced pre-exposure to a rival male mouse (social instigation) resulting in heightened intermale aggression. Both chemogenetic and optogenetic suppression of the LHb-DRN projection blocked heightened aggression after social instigation in male mice.

In contrast, inhibition of this pathway did not affect basal levels of aggressive behavior, suggesting that the activity of the LHb-DRN projection is not necessary for the expression of species-typical aggressive behavior, but required for the increase of aggressive behavior resulting from social instigation.

Anatomical analysis showed that LHb neurons synapse on non-serotonergic DRN neurons that project to the ventral tegmental area (VTA), and optogenetic activation of the DRN-VTA projection increased aggressive behaviors.

Our results demonstrate that the LHb glutamatergic inputs to the DRN promote aggressive arousal induced by social instigation, which contributes to aggressive behavior by activating VTA-projecting non-serotonergic DRN neurons as one of its potential targets.

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Making Sense of Socially Enhanced Aggression in the Brain - Neuroscience News