Neuromuscular disease

Neuromuscular disease is a very broad term that encompasses many diseases and ailments that impair the functioning of the muscles, either directly, being pathologies of the voluntary muscle, or indirectly, being pathologies of nerves or neuromuscular junctions.[1][2]

Neuromuscular diseases are those that affect the muscles and/or their direct nervous system control, problems with central nervous control can cause either spasticity or some degree of paralysis (from both lower and upper motor neuron disorders), depending on the location and the nature of the problem. Some examples of central disorders include cerebrovascular accident, Parkinson’s disease, multiple sclerosis, Huntington’s disease and Creutzfeldt–Jakob disease. Spinal muscular atrophies are disorders of lower motor neuron while amyotrophic lateral sclerosis is a mixed upper and lower motor neuron condition.[medical citation needed]

Symptoms/signs

Symptoms of neuromuscular disease may include the following:[1][3]

Causes

Neuromuscular disease can be caused by autoimmune disorders,[4] genetic/hereditary disorders [1] and some forms of the collagen disorder Ehlers–Danlos Syndrome,[5] exposure to environmental chemicals and poisoning which includes heavy metal poisoning.[6] The failure of the electrical insulation surrounding nerves, the myelin, is seen in certain deficiency diseases, such as the failure of the body’s system for absorbing vitamin B-12[6]

Diseases of the motor end plate include myasthenia gravis, a form of muscle weakness due to antibodies against acetylcholine receptor,[7] and its related condition Lambert-Eaton myasthenic syndrome (LEMS).[8] Tetanus and botulism are bacterial infections in which bacterial toxins cause increased or decreased muscle tone, respectively.[9]Muscular dystrophies, including Duchenne’s and Becker’s, are a large group of diseases, many of them hereditary or resulting from genetic mutations, where the muscle integrity is disrupted, they lead to progressive loss of strength and decreased life span.[10]

Further causes of neuromuscular diseases are :

Polymyositis

Inflammatory muscle disorders

Tumors

Mechanism

In terms of the mechanism of neurological diseases, it depends on which one—whether it is amyotrophic lateral sclerosis, myasthenia gravis or some other NMD.[1]One finds that in muscular dystrophy (Duchenne), gene therapy might have promise as a treatment, since the mutation in a nonessential exon, can be improved via exon-skipping.[16]

Diagnosis

Nerve conduction velocity (study)

Diagnostic procedures that may reveal muscular disorders include direct clinical observations. This usually starts with the observation of bulk, possible atrophy or loss of muscle tone. Neuromuscular disease can also be diagnosed by testing the levels of various chemicals and antigens in the blood, and using electrodiagnostic medicine tests[17] including electromyography[18] (measuring electrical activity in muscles) and nerve conduction studies.[19]

In neuromuscular disease evaluation, it is important to perform musculoskeletal and neurologic examinations. Genetic testing is an important part of diagnosing inherited neuromuscular conditions.

Source: wiki

Closed Loop System Could Detect and Heal Disease by Modulating Peripheral Nerve Activity

Integrated, international efforts under ElectRx program blend mapping of neural circuits and development of novel bio-electrical interfaces.

DARPA has selected seven teams of researchers to begin work on the Agency’s Electrical Prescriptions (ElectRx) program, which has as its goal the development of a closed-loop system that treats diseases by modulating the activity of peripheral nerves. The teams will initially pursue a diverse array of research and technological breakthroughs in support of the program’s technical goals. Ultimately, the program envisions a complete system that can be tested in human clinical trials aimed at conditions such as chronic pain, inflammatory disease, post-traumatic stress and other illnesses that may not be responsive to traditional treatments.

“The peripheral nervous system is the body’s information superhighway, communicating a vast array of sensory and motor signals that monitor our health status and effect changes in brain and organ functions to keep us healthy,“ said Doug Weber, the ElectRx program manager and a biomedical engineer who previously worked as a researcher for the Department of Veterans Affairs. “We envision technology that can detect the onset of disease and react automatically to restore health by stimulating peripheral nerves to modulate functions in the brain, spinal cord and internal organs.”

The oldest and simplest example of this concept is the cardiac pacemaker, which uses brief pulses of electricity to stimulate the heart to beat at a healthy rate. Extending this concept to other organs like the spleen may offer new opportunities for treating inflammatory diseases such as rheumatoid arthritis. Fighting inflammation may also provide new treatments for depression, which growing evidence suggests might be caused in part by excess levels of inflammatory biomolecules. Peripheral nerve stimulation may also be used to regulate production of neurochemicals that regulate learning and memory in the brain, offering new treatments for post-traumatic stress and other mental health disorders.

“Through the combination of a growing understanding of how the nervous system regulates many aspects of our health and advancing technology to measure and stimulate nerve signals, I believe we’re poised to make fundamental changes to the way we diagnose and treat disease,” Weber said. “To that end, DARPA has assembled a performer team and outlined a research way-ahead that we anticipate can move us toward a capability to safely and reliably modulate the peripheral nervous system to fight disease.”

The main thrusts for Phase I of ElectRx are fundamental studies to map the neural circuits governing the physiology of diseases of interest to DARPA and preliminary development of novel, minimally invasive neural and bio-interface technologies with unprecedented levels of precision, targeting and scale. The teams include a mix of first-time and prior DARPA performers. Many have partnered with established medical device manufacturers to support trials in the near term and ultimately facilitate transition of ElectRx interface devices as they mature.

  • Circuit Therapeutics (Menlo Park, Calif.), a start-up co-founded by Karl Deisseroth and Scott Delp, is a new DARPA performer. The team plans to further develop its experimental optogenetic methods for treating neuropathic pain, building toward testing in animal models before seeking to move to clinical trials in humans.
  • A team at Columbia University (New York), led by Elisa Konofagou, will pursue fundamental science to support the use of non-invasive, targeted ultrasound for neuromodulation. The team aims to elucidate the underlying mechanisms that may make ultrasound an option for chronic intervention, including activation and inhibition of nerves.
  • A team at the Florey Institute of Neuroscience and Mental Health (Parkville, Australia), led by John Furness, is a first-time DARPA performer. Team members will seek to map the nerve pathways that underlie intestinal inflammation, with a focus on determining the correlations between animal models and human neural circuitry. They will also explore the use of neurostimulation technologies based on the cochlear implant —developed by Cochlear, Inc. to treat hearing loss, but adapted to modulate activity of the vagus nerve in response to biofeedback signals—as a possible treatment for inflammatory bowel disease.
  • A team at the Johns Hopkins University (Baltimore), led by Jiande Chen, aims to explore the root mechanisms of inflammatory bowel disease and the impact of sacral nerve stimulation on its progression. The team will apply a first-of-its-kind approach to visualize intestinal responses to neuromodulation in animal models.
  • A team at the Massachusetts Institute of Technology (Cambridge, Mass.), led by Polina Anikeeva, will aim to advance its established work in magnetic nanoparticles for localized, precision in vivo neuromodulation through thermal activation of neurons in animal models. The team’s work will target the adrenal gland and the splanchnic nerve circuits that govern its function. To increase specificity and minimize potential side effects of this method of stimulation, the team seeks to develop nanoparticles with the ability to bind to neuronal membranes. Dr. Anikeeva was previously a DARPA Young Faculty Awardee.
  • A team at Purdue University (West Lafayette, Ind.), led by Pedro Irazoqui, will leverage an existing collaboration with Cyberonics to study inflammation of the gastrointestinal tract and its responsiveness to vagal nerve stimulation through the neck. Validation of the mechanistic insights that emerge from the effort will take place in pre-clinical models in which novel neuromodulation devices will be applied to reduce inflammation in a feedback-controlled manner. Later stages of the effort could advance the design of clinical neuromodulation devices.
  • A team at the University of Texas, Dallas, led by Robert Rennaker and Michael Kilgard, will examine the use of vagal nerve stimulation to induce neural plasticity for the treatment of post-traumatic stress. As envisioned, stimulation could enhance learned behavioral responses that reduce fear and anxiety when presented with traumatic cues. Dr. Rennaker is a U.S. Marine Corps veteran who served in Liberia, Kuwait and Yugoslavia.

Concept diagram of ElectRx technologies.

“Using the peripheral nervous system as a medium for delivering therapy is largely new territory and it’s rich with potential to manage many of the conditions that impact the readiness of our military and, more generally, the health of the nation,” Weber said. “It will be an exciting path forward.”

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Source: DARPA
Image Source: The image is credited to DARPA

Vagus Nerve Stimulation May Reduce Rheumatoid Arthritis Symptoms

vagusSummary: A new study reports vagus nerve stimulation reduces symptoms of RA, cytokine levels and inflammation.

Source: Northwell Health.

Clinical trial data published in the Proceedings of the National Academy of Sciences (PNAS) demonstrates stimulating the vagus nerve with an implantable bioelectronic device significantly improved measures of disease activity in patients with rheumatoid arthritis (RA). RA is a chronic inflammatory disease that affects 1.3 million people in the United States and costs tens of billions of dollars annually to treat. The findings, announced by the Academic Medical Center/University of Amsterdam, the Feinstein Institute for Medical Research and SetPoint Medical, appear online in PNAS Early Edition and will appear in an upcoming print issue.

The publication, titled “Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis,” highlights a human study designed to reduce symptoms of RA, cytokine levels and inflammation by stimulating the vagus nerve with a small implanted device.

“This is the first study to evaluate whether stimulating the inflammatory reflex directly with an implanted electronic device can treat RA in humans,” said Professor Paul-Peter Tak, MD, PhD, FMedSci, the international principal investigator and lead author of the paper at the Division of Clinical Immunology & Rheumatology of the Academic Medical Center/University of Amsterdam. “We have previously shown that targeting the inflammatory reflex may reduce inflammation in animal models and in vitro models of RA. The direct correlation between vagus nerve stimulation and the suppression of several key cytokines like TNF as well as reduced RA signs and symptoms demonstrates proof of mechanism, which might be relevant for other immune-mediated inflammatory diseases as well.”

“Our findings suggest a new approach to fighting diseases with bioelectronic medicines, which use electrical pulses to treat diseases currently treated with potent and relatively expensive drugs,” said Anthony Arnold, Chief Executive Officer of SetPoint Medical. “These results support our ongoing development of bioelectronic medicines designed to improve the lives of people suffering from chronic inflammatory diseases and give healthcare providers new and potentially safer treatment alternatives at a much lower total cost for the healthcare system.”

“This is a real breakthrough in our ability to help people suffering from inflammatory diseases,” said co-author Kevin J. Tracey, MD, president and CEO of the Feinstein Institute for Medical Research, discoverer of the inflammatory reflex and co-founder of SetPoint Medical. “While we’ve previously studied animal models of inflammation, until now we had no proof that electrical stimulation of the vagus nerve can indeed inhibit cytokine production and reduce disease severity in humans. I believe this study will change the way we see modern medicine, helping us understand that our nerves can, with a little help, make the drugs that we need to help our body heal itself.”

While focused on rheumatoid arthritis, the trial’s results may have implications for patients suffering from other inflammatory diseases, including Crohn’s, Parkinson’s, Alzheimer’s and others.

Study Methodology and Results

In the study, a stimulation device was implanted on the vagus nerve during a surgical procedure, then activated and deactivated based on a set schedule to measure response over 84 days, with primary endpoints measured at day 42 using DAS28-CRP, a standard disease activity composite score for RA that includes counts of tender and swollen joints, patient’s and physician’s assessment of disease activity and serum C-reactive protein (CRP) levels.

Photo of hand of a person with RA.

Of 17 patients with active RA in the study, several patients that had failed to respond to multiple therapies, including biologicals with different mechanisms of action, demonstrated robust responses. The findings indicate that active electrical stimulation of the vagus nerve inhibits TNF production in RA patients and significantly attenuates RA disease severity.

Several patients reported significant improvements, including some who had previously failed to respond to any other form of pharmaceutical treatment. In addition, no serious adverse side effects were reported.

The emerging field of bioelectronic medicine aims to target disorders traditionally treated with drugs and instead uses advanced neuromodulation devices that may offer significant advantages. SetPoint is developing a novel proprietary bioelectronic medicine platform to treat a variety of immune-mediated inflammatory diseases, using an implanted device to stimulate the vagus nerve.

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Source: Emily Ng – Northwell Health
Image Source: This NeuroscienceNews.com image is credited to James Heilman, MD and is licensed CC BY SA 3.0.
Original Research: The study will appear in PNAS.

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Northwell Health. “Vagus Nerve Stimulation May Reduce Rheumatoid Arthritis Symptoms.” NeuroscienceNews. NeuroscienceNews, 5 July 2016.
<http://neurosciencenews.com/ra-vagus-nerve-stimulation-4614/&gt;.

Nervous system and nerve-growth factor (NGF) play a major role in arthritis

Reducing levels of nerve-growth factor may be a key to developing better pain treatments.

Arthritis is a debilitating disorder affecting one in 10 Canadians, with pain caused by inflammation and damage to joints.

Yet the condition is poorly managed in most patients, since adequate treatments are lacking – and the therapies that do exist to ease arthritis pain often cause serious side effects, particularly when used long-term. Any hope for developing more-effective treatments for arthritis relies on understanding the processes driving this condition.

A new study in the Journal of Neuroscience by researchers at McGill University adds to a growing body of evidence that the nervous system and nerve-growth factor (NGF) play a major role in arthritis. The findings also support the idea that reducing elevated levels of NGF – a protein that promotes the growth and survival of nerves, but also causes pain — may be an important strategy for developing treatment of arthritis pain.

The image shows the sympathetic nerve fibers. The caption best describes the image.

Using an approach established by arthritis researchers elsewhere, the McGill scientists examined inflammatory arthritis in the ankle joint of rats. In particular, they investigated changes in the nerves and tissues around the arthritic joint, by using specific markers to label the different types of nerve fibres and allow them to be visualized with a fluorescence microscope.

Normally, sympathetic nerve fibres regulate blood flow in blood vessels. Following the onset of arthritis in the rats, however, these fibres began to sprout into the inflamed skin over the joint and wrap around the pain-sensing nerve fibres instead. More sympathetic fibres were detected in the arthritic joint tissues, as well.

The results also showed a higher level in the inflamed skin of NGF – mirroring the findings of human studies that have shown considerable increases in NGF levels in arthritis patients.

To investigate the role of these abnormal sympathetic fibres, the McGill researchers used an agent to block the fibres’ function. They found that this reduced pain-related behaviour in the animals.

“Our findings reinforce the idea that there is a neuropathic component to arthritis, and that sympathetic nerve fibres play a role in increasing the pain,” said McGill doctoral student Geraldine Longo, who co-authored the paper with Prof. Afredo Ribeiro-da-Silva and postdoctoral fellow Maria Osikowicz.

“We are currently using drugs to prevent the production of elevated levels of NGF in arthritic rats; we hope that our research will serve as a basis for the development of a new treatment for arthritis in the clinic”, said Prof. Ribeiro-da-Silva.

Notes about this neurology and arthritis research

This research was funded by grants from the Canadian Institutes of Health Research (CIHR), the Louise and Alan Edwards Foundation, and the MITACS-Accelerate Quebec program in partnership with Pfizer Canada.

Contact: Chris Chipello – McGill University
Source: McGill University press release
Image Source: The nerve fiber image is credited to Geraldine Longo and is adapted from the McGill University press release.
Original Research: Abstract for “Sympathetic Fiber Sprouting in Inflamed Joints and Adjacent Skin Contributes to Pain-Related Behavior in Arthritis” by Geraldine Longo, Maria Osikowicz, and Alfredo Ribeiro-da-Silva in Journal of Neuroscience. Published online June 12 2013 doi: 10.1523/JNEUROSCI.5784-12.2013

Babies Exposed to Stimulation Get a Brain Boost

Summary: Contrary to popular belief, exposing children to stimuli early can help to boost their development, researchers report.

Source: NTNU.

Many new parents still think that babies should develop at their own pace, and that they shouldn’t be challenged to do things that they’re not yet ready for. Infants should learn to roll around under their own power, without any “helpful” nudges, and they shouldn’t support their weight before they can stand or walk on their own. They mustn’t be potty trained before they are ready for it.

According to neuroscientist Audrey van der Meer, a professor at the Norwegian University of Science and Technology (NTNU) this mindset can be traced back to the early 1900s, when professionals were convinced that our genes determine who we are, and that child development occurred independently of the stimulation that a baby is exposed to. They believed it was harmful to hasten development, because development would and should happen naturally.

Early stimulation in the form of baby gym activities and early potty training play a central role in Asia and Africa. The old development theory also contrasts with modern brain research that shows that early stimulation contributes to brain development gains even in the wee ones among us.

Using the body and senses

Van der Meer is a professor of neuropsychology and has used advanced EEG technology for many years to study the brain activity of hundreds of babies.

The results show that the neurons in the brains of young children quickly increase in both number and specialization as the baby learns new skills and becomes more mobile. Neurons in very young children form up to a thousand new connections per second.

Van der Meer’s research also shows that the development of our brain, sensory perception and motor skills happen in sync. She believes that even the smallest babies must be challenged and stimulated at their level from birth onward. They need to engage their entire body and senses by exploring their world and different materials, both indoors and out and in all types of weather. She emphasizes that the experiences must be self-produced; it is not enough for children merely to be carried or pushed in a stroller.

Unused brain synapses disappear

“Many people believe that children up to three years old only need cuddles and nappy changes, but studies show that rats raised in cages have less dendritic branching in the brain than rats raised in an environment with climbing and hiding places and tunnels. Research also shows that children born into cultures where early stimulation is considered important, develop earlier than Western children do,” van der Meer says.

She adds that the brains of young children are very malleable, and can therefore adapt to what is happening around them. If the new synapses that are formed in the brain are not being used, they disappear as the child grows up and the brain loses some of its plasticity.

Van der Meer mentions the fact that Chinese babies hear a difference between the R and L sounds when they are four months old, but not when they get older. Since Chinese children do not need to distinguish between these sounds to learn their mother tongue, the brain synapses that carry this knowledge disappear when they are not used.

Loses the ability to distinguish between sounds

Babies actually manage to distinguish between the sounds of any language in the world when they are four months old, but by the time they are eight months old they have lost this ability, according to van der Meer.

In the 1970s, it was believed that children could only learn one language properly. Foreign parents were advised not to speak their native language to their children, because it could impede the child’s language development. Today we think completely differently, and there are examples of children who speak three, four or five languages fluently without suffering language confusion or delays.

Brain research suggests that in these cases the native language area in the brain is activated when children speak the languages. If we study a foreign language after the age of seven, other areas of the brain are used when we speak the language, explains Van der Meer.

She adds that it is important that children learn languages by interacting with real people.

“Research shows that children don’t learn language by watching someone talk on a screen, it has to be real people who expose them to the language,” says van der Meer.

Early intervention with the very young

Since a lot is happening in the brain during the first years of life, van der Meer says that it is easier to promote learning and prevent problems when children are very young.

The term “early intervention” keeps popping up in discussions of kindergartens and schools, teaching and learning. Early intervention is about helping children as early as possible to ensure that as many children as possible succeed in their education and on into adulthood – precisely because the brain has the greatest ability to change under the influence of the ambient conditions early in life.

“When I talk about early intervention, I’m not thinking of six-year-olds, but even younger children from newborns to age three. Today, 98 per cent of Norwegian children attend kindergarten, so the quality of the time that children spend there is especially important. I believe that kindergarten should be more than just a holding place – it should be a learning arena – and by that I mean that play is learning,” says van der Meer.

Too many untrained staff

She adds that a two-year old can easily learn to read or swim, as long as the child has access to letters or water. However, she does not want kindergarten to be a preschool, but rather a place where children can have varied experiences through play.

“This applies to both healthy children and those with different challenges. When it comes to children with motor challenges or children with impaired vision and hearing, we have to really work to bring the world to them,” says van der Meer.

“One-year-olds can’t be responsible for their own learning, so it’s up to the adults to see to it. Today untrained temporary staff tend to be assigned to the infant and toddler rooms, because it’s ‘less dangerous’ with the youngest ones since they only need cuddles and nappy changes. I believe that all children deserve teachers who understand how the brains of young children work. Today, Norway is the only one of 25 surveyed OECD countries where kindergarten teachers do not constitute 50 per cent of kindergarten staffing,” she said.

More children with special needs

Lars Adde is a specialist in paediatric physical therapy at St. Olavs Hospital and a researcher at NTNU’s Department of Laboratory Medicine, Children’s and Women’s Health. He works with young children who have special needs, in both his clinical practice and research.

Image shows a baby playing.

He believes it is important that all children are stimulated and get to explore the world, but this is especially important for children who have special challenges. He points out that a greater proportion of children that are now coming into the world in Norway have special needs.

“This is due to the rapid development in medical technology, which enables us to save many more children – like extremely premature babies and infants who get cancer. These children would have died 50 years ago, and today they survive – but often with a number of subsequent difficulties,” says Adde.

New knowledge offers better treatment

Adde says that the new understanding of brain development that has been established since the 1970s has given these children far better treatment and care options.

For example, the knowledge that some synapses in the brain are strengthened while others disappear has led to the understanding that we have to work at what we want to be good at – like walking. According to the old mindset, any general movement would provide good general motor function.

Babies who are born very prematurely at St. Olavs Hospital receive follow-up by an interdisciplinary team at the hospital and a municipal physiotherapist in their early years. Kindergarten staff where the child attends receive training in exactly how this child should be stimulated and challenged at the appropriate level. The follow-up enables a child with developmental delays to catch up quickly, so that measures can be implemented early – while the child’s brain is still very plastic.

A child may, for example, have a small brain injury that causes him to use his arms differently. Now we know that the brain connections that govern this arm become weaker when it is used less, which reinforces the reduced function.

“Parents may then be asked to put a sock on the “good” hand when their child uses his hands to play. Then the child is stimulated and the brain is challenged to start using the other arm,” says Adde.

Shouldn’t always rush development

Adde stresses that it is not always advisable to speed up the development of children with special needs who initially struggle with their motor skills.

A one–year old learning to walk first has to learn to find her balance. If the child is helped to standing position, she will eventually learn to stand – but before she has learned how to sit down again. If the child loses her balance, she’ll fall like a stiff cane, which can be both scary and counterproductive.

In that situation, “we might then ask the parents to instead help their child up to kneeling position while it holds onto something. Then the child will learn to stand up on its own. If the child falls, it will bend in the legs and tumble on its bum. Healthy children figure this out on their own, but children with special challenges don’t necessarily do this,” says Adde.

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Source: NTNU
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Full open access research for “Development of Visual Motion Perception for Prospective Control: Brain and Behavioral Studies in Infants” by Seth B. Agyei, F. R. (Ruud) van der Weel and Audrey L. H. van der Meer in Frontiers in Psychology. Published online February 9 2016 doi:10.3389/fpsyg.2016.00100

Abstract for “Longitudinal study of preterm and full-term infants: High-density EEG analyses of cortical activity in response to visual motion” bySeth B. Agyei, F.R. (Ruud) van der Weel, Audrey L.H. van der Meer in Neuropsychologia. Published online April 2016 doi:10.1016/j.neuropsychologia.2016.02.001

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NTNU “Babies Exposed to Stimulation Get a Brain Boost.” NeuroscienceNews. NeuroscienceNews, 30 January 2017.
<http://neurosciencenews.com/baby-stimulation-neurodevelopment-5844/&gt;.

Abstract

Development of Visual Motion Perception for Prospective Control: Brain and Behavioral Studies in Infants

During infancy, smart perceptual mechanisms develop allowing infants to judge time-space motion dynamics more efficiently with age and locomotor experience. This emerging capacity may be vital to enable preparedness for upcoming events and to be able to navigate in a changing environment. Little is known about brain changes that support the development of prospective control and about processes, such as preterm birth, that may compromise it. As a function of perception of visual motion, this paper will describe behavioral and brain studies with young infants investigating the development of visual perception for prospective control. By means of the three visual motion paradigms of occlusion, looming, and optic flow, our research shows the importance of including behavioral data when studying the neural correlates of prospective control.

“Development of Visual Motion Perception for Prospective Control: Brain and Behavioral Studies in Infants” by Seth B. Agyei, F. R. (Ruud) van der Weel and Audrey L. H. van der Meer in Frontiers in Psychology. Published online February 9 2016 doi:10.3389/fpsyg.2016.00100


Abstract

Longitudinal study of preterm and full-term infants: High-density EEG analyses of cortical activity in response to visual motion

Electroencephalogram (EEG) was used to investigate brain electrical activity of full-term and preterm infants at 4 and 12 months of age as a functional response mechanism to structured optic flow and random visual motion. EEG data were recorded with an array of 128-channel sensors. Visual evoked potentials (VEPs) and temporal spectral evolution (TSE, time-dependent amplitude changes) were analysed. VEP results showed a significant improvement in full-term infants’ latencies with age for forwards and reversed optic flow but not random visual motion. Full-term infants at 12 months significantly differentiated between the motion conditions, with the shortest latency observed for forwards optic flow and the longest latency for random visual motion, while preterm infants did not improve their latencies with age, nor were they able to differentiate between the motion conditions at 12 months. Differences in induced activities were also observed where comparisons between TSEs of the motion conditions and a static non-flow pattern showed desynchronised theta-band activity in both full-term and preterm infants, with synchronised alpha-beta band activity observed only in the full-term infants at 12 months. Full-term infants at 12 months with a substantial amount of self-produced locomotor experience and neural maturation coupled with faster oscillating cell assemblies, rely on the perception of structured optic flow to move around efficiently in the environment. The poorer responses in the preterm infants could be related to impairment of the dorsal visual stream specialized in the processing of visual motion.

“Longitudinal study of preterm and full-term infants: High-density EEG analyses of cortical activity in response to visual motion” bySeth B. Agyei, F.R. (Ruud) van der Weel, Audrey L.H. van der Meer in Neuropsychologia. Published online April 2016 doi:10.1016/j.neuropsychologia.2016.02.001

GWAS identifies genomic locations linked to personality traits and psychiatric disorders

A meta-analysis of genome-wide association studies (GWAS) has identified six loci or regions of the human genome that are significantly linked to personality traits, report researchers at University of California San Diego School of Medicine in this week’s advance online publication of Nature Genetics. The findings also show correlations with psychiatric disorders.

“Although personality traits are heritable, it has been difficult to characterize genetic variants associated with personality until recent, large-scale GWAS,” said senior author Chi-Hua Chen, PhD, assistant professor in the Department of Radiology at UC San Diego School of Medicine.

Five psychological factors are commonly used to measure individual differences in personality:

  • Extraversion (versus introversion) reflects talkativeness, assertiveness and a high activity level
  • Neuroticism (versus emotional stability) reflects negative affect, such as anxiety and depression
  • Agreeableness (versus antagonism) measures cooperativeness and compassion
  • Conscientiousness (versus undependability) indicates diligence and self-discipline
  • Openness to experience (versus being closed to experience) suggests intellectual curiosity and creativity

Psychologists and others define personality phenotypes — sets of observable characteristics — based upon quantitative scoring of these five factors. Past meta-analyses of twin and family studies have attributed approximately 40 percent of variance in personality to genetic factors. GWAS, which look for genetic variations across a large sampling of people, have discovered several variants associated with the five factors.

In their new paper, Chen and colleagues analyzed genetic variations among the five personality traits and six psychiatric disorders, using data from 23andMe, a privately held personal genomics and biotechnology company, the Genetics of Personality Consortium, a European-based collaboration of GWAS focusing on personality questions, UK Biobank and deCODE Genetics, an Iceland-based human genetics company.

The researchers found, for example, that extraversion was associated with variants in the gene WSCD2 and near gene PCDH15; neuroticism was associated with variants on chromosome 8p23.1 and gene L3MBTL2. Personality traits were largely separated genetically from psychiatric disorders, except for neuroticism and openness to experience, which clustered in the same genomic regions as the disorders.

In addition, there were high genetic correlations between extraversion and attention deficit hyperactivity disorder (ADHD) and between openness and schizophrenia and bipolar disorder. Neuroticism was genetically correlated with internalized psychopathologies, such as depression and anxiety.

“We identified genetic variants linked to extraversion and neuroticism personality traits,” said Chen. “Our study is in an early stage for genetic research in personality and many more genetic variants associated with personality traits are to be discovered. We found genetic correlations between personality traits and psychiatric disorders, but specific variants underlying the correlations are unknown.”

The authors note that while the sample size of the meta-analyses was large (123,132 to 260,861 participants in different studies), they used only GWAS summary statistics and cannot estimate all genetic variance factors; some studies also used different methodologies.

Source:

University of California – San Diego


Email motherhealth@gmail.com for the $1300 GWAS genetic tests from our lab in Davis, California and New Jersey.  You need a genetic counselor to work with the bioinformatics with you. And a doctor, to get some kind of health insurance reimbursements.