Neuroscience

Cannabis medicine tested in child epilepsy

Doctors in the UK have been given the go-ahead to test the medicine, which does not contain the ingredient that produces the high associated with recreational cannabis use.

The treatment - called Epidiolex - is based on one of the non-psychoactive components of the cannabis plant, called CBD.

UK first

Early studies in the US have shown that treatment with CBD may reduce the frequency and severity of seizures in children with severe forms of epilepsy. The new trial marks the first time the treatment has been tested in the UK.

Clinical trial

Patients are being enrolled for a randomised controlled trial of the treatment at The University of Edinburgh’s Muir Maxwell Epilepsy Centre, based at the Royal Hospital for Sick Children in Edinburgh, and Great Ormond Street Hospital.

The Royal Hospital for Sick Children in Glasgow and Alder Hey Children’s Hospital in Liverpool are also driving the study. There are further centres in the US, France and Poland.

Many children with serious forms of epilepsy do not respond to the medications that we currently have available. We need new means of treating these conditions so that we can give back some quality of life to these children and their families. -Dr Richard Chin (Director of the Muir Maxwell Epilepsy Centre, University of Edinburgh).

Severe epilepsy

The initial focus will be on children with Dravet Syndrome, a rare but serious type of epilepsy that is difficult to treat. Some children will receive the treatment while others will receive a placebo.

In a further phase, researchers will also study the effect on children with Lennox-Gastaut Syndrome.

Only children whose seizures cannot be controlled with existing medications will be invited to take part in the trial.

Dravet Syndrome

Dravet Syndrome usually takes hold in the first year of life. It causes seizures that are often prolonged, lasting longer than five minutes. Patients then develop other seizure types. This has a significant impact on the child’s development and can be fatal in some cases.

Epidiolex

Epidiolex has been developed by the British biotechnology company GW Pharmaceuticals, which is sponsoring and funding the trial.

I welcome the launch of these trials as it marks an important milestone in our long journey towards understanding the condition and improving the treatment of those suffering this severe form of epilepsy. As the mother of a teenager with this life altering condition, I strongly support the exploration of ground breaking medications that could seek out new ways to improve patients’ life quality. -Ann Maxwell (Founder, Muir Maxwell Trust).

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The Mind-Controlled Robotic Arm Is Getting More Nimble

Impressive. Snip from Motherboard:

Two years ago, the world mar​velled as Jan Scheuermann, a quadriplegic woman, moved a robotic arm using her mind. Her motions were awkward and clunky as she grabbed a chocolate bar full-fisted, like a baby, easing it towards her face for a nibble.

Now, she can not just grab a chocolate bar, she can pinch a piece, eat it, and give the thumbs-up, if it’s particularly tasty. Researchers at the University of Pittsburgh spent tw​o years fine-tuning the technology and the computer algorithm that translates the electricity emitted from neurons firing in Scheuermann’s brain to the movements of the robotic arm. Now, instead of moving in just seven dimensions, the robotic hand can move in ten different dimensions.

Watch as Scheuermann demonstrates the new abilities, as she more nimbly—though still occasionally clumsily—picks up and maneuvers blocks and balls of different sizes around a surface.

[read more] [paper]

Lost Memories Might Be Able to Be Restored, Researchers Report

Read the full article Lost Memories Might Be Able to Be Restored, Researchers Report at NeuroscienceNews.com.

Research reveals that memories may not be stored in synapses, as previously thought.

The research is in eLife. (full open access)

Research: “Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia” by Shanping Chen, Diancai Cai, Kaycey Pearce, Philip Y-W Sun, Adam C Roberts, David L Glanzman in eLife. doi:10.7554/eLife.03896 (http://dx.doi.org/10.7554/eLife.03896)

Image: The new study provides evidence contradicting the idea that long-term memory is stored in synapses. This image is for illustrative purposes only and is in the public domain.

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NEW VIDEO! Does the beat always beat you? Why some people can’t hear music.

Did you know that gray matter, which makes up 40% of the brain, doesn’t turn gray until after death? A living brain has a more pinkish hue, and, according to scientists, feels similar to tofu.

More interesting brain facts can be found at Mic, where we’re partnering to share the latest advances in brain research and technology with a one-month series exploring the universe in our heads. 

GIF by Cindy Suen

Certainty in our choices often a matter of time

When faced with making choices, but lack sufficient evidence to guarantee success, our brain uses elapsed time as a proxy for task difficulty to calculate how confident we should be, a team of neuroscientists has found. Their findings, which appear in the journal Neuron, help untangle the different factors that contribute to the decision-making process.

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“In our daily lives, we make many decisions,” says Roozbeh Kiani, an assistant professor in NYU’s Center for Neural Science and one of the study’s authors. “Sometimes the evidence afforded us is strong, enabling us to decide quickly and accurately. Other times, the evidence is lacking; we take longer to decide and tend to be less accurate. Our brain can learn that longer elapsed times are associated with lower accuracy and should mean less confidence.

“Our findings show that our brains use this association to calculate confidence, not just based on the available evidence, but also based on how long it takes to gather the evidence.”

“It’s an intriguing notion that the brain might convert its data—gathered through the senses—into units of ‘degree of belief’ by combining evidence and elapsed time,” adds co-author Michael Shadlen, MD, a professor of neuroscience at Columbia University, an investigator of the Howard Hughes Medical Institute, and a member of Columbia’s Mortimer B. Zuckerman Mind Brain Behavior Institute. “Those same regularities that support the intuition that time might matter also made it challenging to identify time itself as a player and not just a marker for something else, such as accuracy.

“It makes intuitive sense that ‘time spent’ would serve as a clue about difficulty; proving it in the lab was not easy though. No wonder it took until 2014 to do it!”

It has been established that decisions are usually accompanied by a degree of certainty or confidence, a graded belief that our choices will produce positive outcomes. Confidence plays a critical role in guiding our future behavior in complex environments, especially when decision outcomes are delayed and rapid learning is required.

Less understood, however, is how this certainty is established. Researchers have attributed it to a pair of variables: evidence and decision time. Specifically, if we believe we have sufficient evidence for making a decision, we’re more likely to be certain in making a choice. When it comes to time, the quickness of a decision is seen as a reflection of confidence—the more rapidly we make a decision, the more confident we are in making it.

However, it is challenging to separate these two factors as the evidence supporting a specific choice typically affects the time we use to make it.

To address this, the researchers designed an experiment in which the participants were asked to decide on the direction of motion (up or down) in a random-dot motion display—that is, in which direction were the dots headed? Participants answered by making an eye movement to either an up or down horizontal bar, directing their gaze toward one or the other end of the bar to indicate the level of confidence in the decision. The simultaneous expression of choice and confidence ensured that participants were using the same information to guide both aspects of the decision. The researchers controlled the level of difficulty—the noisiness—of the motion and tracked the eye movements to ascertain the choice, amount of time to make the choice, and the confidence in that choice.

Their results showed that, not surprisingly, more evidence boosted the confidence of responses. Moreover, certainty was inversely correlated with reaction times: in other words, the less time it took to make a decision, the more confidence subjects felt about their decisions.

In a second experiment, the researchers dissociated the effect of time and evidence on confidence by manipulating the evidence, so that for a brief period the net evidence was near zero. Subjects increased their decision times to achieve the same level of accuracy as before. Importantly, however, the reported confidence was lower, indicating that increased decision time can diminish the confidence even in the absence of appreciable changes in accuracy.

“We showed for the first time that the relationship between decision time and confidence is not fully mediated by evidence—elapsed time plays an independent role,” observes Kiani. “In many situations using the elapsed time is advantageous. It offers a computational shortcut and improves the reliability of calculated confidence. However, it also shows that we can dissociate accuracy and confidence by a manipulation like that used in our experiment.”

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Beautiful online neuroscience learning

The Fundamentals of Neuroscience is a free online course from Harvard and it looks wonderful – thanks to them employing animators, digital artists and scientists to lift the course above the usual read and repeat learning.

The course is already underway but you can register and start learning until mid-December and you can watch any of the previews to get a feel for what’s being taught. You need to register to access the full content but there’s plenty of trailers online. Great stuff.

Link to ‘Fundamentals of Neuroscience’ course.

Source: Mind Hacks

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Empathy & Compassion in the brain

Empathy is a complicated task for the brain.

Reptiles probably can’t do it and it’s going to occur in pretty simple forms for most mammals. But in humans, it really engages the frontal lobes: these newer regions of the brain that are involved in more complex symbolic processes like language, considering alternatives and imagining the future. Empathy requires that you think: there’s someone else out there who has feelings and thoughts that may be different from mine.  That’s a complicated cognitive achievement!

Compassion —the caring instinct— is located down in the center of the brain, near the top of the spinal cord where a lot of our basic instincts are regulated. It’s a very old part of the brain called the periaqueductal gray, which is common to mammals when they take care of their young.

So that’s striking: there’s one kind of thing —empathy— that’s really about understanding people (very complicated!) in the frontal lobes. But caring is is really old in the nervous system.

Learn about the evolutionary roots of compassion & empathy  →

OCD Patients’ Brains Light up to Reveal How Compulsive Habits Develop

Read the full article OCD Patients’ Brains Light up to Reveal How Compulsive Habits Develop at NeuroscienceNews.com.

Misfiring of the brain’s control system might underpin compulsions in obsessive-compulsive disorder (OCD), according to researchers at the University of Cambridge.

The research is in American Journal of Psychiatry. (full access paywall)

Research: “Functional Neuroimaging of Avoidance Habits in Obsessive-Compulsive Disorder” by Claire M. Gillan, Ph.D.; Annemieke M. Apergis-Schoute, Ph.D.; Sharon Morein-Zamir, Ph.D.; Gonzalo P. Urcelay, Ph.D.; Akeem Sule, M.B.B.S., M.R.C.Psych.; Naomi A. Fineberg, M.A., M.R.C.Psych.; Barbara J. Sahakian, Ph.D.; and Trevor W. Robbins, Ph.D. in American Journal of Psychiatry. doi:10.1176/appi.ajp.2014.14040525 (http://dx.doi.org/10.1176/appi.ajp.2014.14040525)

Image: Researchers have been investigating the possibility that compulsions in OCD are products of an overactive habit-system. Credit Dave 77459.

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Today, Dr. May-Britt Moser from the Norwegian University of Science and Technology (NTNU) accepts her Nobel Prize in true startorial style. Dr. Moser was awarded the 2014 Nobel Prize in Physiology or Medicine together with her colleague (and husband) Edvard Moser and John O’Keefe (of University College London) for discovering grid cells that provide the brain with an internal coordinate system essential for navigation (aka your inner GPS). 

Dr. Moser’s stunning gown was designed by engineer-turned designer, Matthew Hubble. Matthew reached out to us earlier this month about his amazing creation. He believes scientists should be celebrated just as much as movie stars, if not more. We wholeheartedly agree!

After Dr. Moser was announced as a co-winner of this year’s Nobel Prize, he began to research her work and was inspired to design this dress for her. The details represent the neuronal grid of Dr. Moser’s research complete with three large beaded and sequined neurons reaching out to connect with each other across the deep blue fabric.  

For more info on their collaboration, check out Joanne Manaster’s feature for Scientific American (including an interview with Matthew). And you can follow both Dr. Moser and Matthew on Twitter.

We think the result is AMAZING and we are so excited to see a female scientists celebrated in this way. Congrats to Dr. Moser on her Nobel and congrats to Matthew on his incredible gown!

- Summer

(photo credit: Geir Mogen and NTNU)

(Image caption: Sensory nerve terminals (orange) of a muscle spindle. Credit: University of Basel, Biozentrum)

Trigger Mechanism for Recovery After Spinal Cord Injury Revealed

After an incomplete spinal cord injury, the body can partially recover basic motor function. So-called muscle spindles and associated sensory circuits back to the spinal cord promote the establishment of novel neuronal connections after injury. This circuit-level mechanism behind the process of motor recovery was elucidated by Prof. Silvia Arber’s research group at the Biozentrum, University of Basel and the Friedrich Miescher Institute for Biomedical Research. Their findings may contribute to designing novel strategies for treatment after spinal cord injuries and have now been published in the journal Cell.

Spinal cord injuries often lead to chronically impaired motor function. However, patients with incomplete spinal cord injury can partially regain their basic motor ability under certain circumstances. It is believed that remaining uninjured spinal cord tissue provides a substrate to form new circuits bridging the injury. How this formation of new connections is triggered and promoted has remained unclear until now.

In collaboration with Prof. Grégoire Courtine’s research group at the EPFL in Lausanne, the team of Prof. Silvia Arber at the Biozentrum at the University of Basel and the Friedrich Miescher Institute for Biomedical Research (FMI) has demonstrated in a mouse model why paralyzed limbs can move again after incomplete spinal cord injuries: A specific sensory feedback channel connected to sensors embedded within the muscles – so-called muscle spindles – promotes the functional recovery of the damaged neuronal circuits in the spinal cord.

Muscle spindle sensory feedback provides trigger signal for recovery

Limb movement activates sensory feedback loops from the muscle to the spinal cord. This specific feedback channel promotes the repair process of the damaged spinal network after injury. As a result, basic motor function can be restored. “The sensory feedback loops from muscle spindles are therefore a key factor in the recovery process,” says Silvia Arber. After spinal cord injury, these nerve impulses keep providing information to the central nervous system – even when the transmission of information from the brain to the spinal cord no longer functions.

“An important trigger for the recovery process is the information conveyed from the muscle to the central nervous system and not only the top-down information the brain sends towards muscles,” explains the first author Aya Takeoka. In addition, the researchers demonstrated that only basic locomotor functionality could be restored spontaneously after an injury. Fine locomotor task performance tested, however, remained permanently lost.

Treatments must start with activation of muscle spindles

The study suggests that activation of muscle spindles is essential to promote the recovery process of damaged neuronal networks after spinal cord injury. Thus, therapeutic approaches should aim to extensively use the muscles, even if passively after an injury. The more intensely muscles are used in the movement process, the more muscle spindle feedback circuits are stimulated. By applying this principle, the repair of neuronal circuits and the accompanying recovery of basic motor skills will have the best chances of succeeding.

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“Science is the field where we can make the impossible possible.”
— Dr. May-Britt Moser, the Norwegian
psychologist and neuroscientist, who today accepted Nobel Prize in Physiology or Medicine (with Edvard Moser and John O’Keefe) for the discovery of cells that provide a positioning system in the brain essential for navigation
read more here and here

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Got books on the brain? Why not get some books on the brain? (Work it out.)

The 2014 Society for Neuroscience Annual Meeting is taking place November 15-19 in Washington D.C. If you’re attending the meeting, stop by booth 200 to check out these books and more.

Any brainy books to add to the list? 

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(Figure 1 (left): This is a freeze fracture replica image showing the voltage-gated calcium channels clusters on presynaptic membrane in rats. The green circles represent channel clusters, and inside each green circle are small black dots, which are the individual channels. This is easier to see in the inset, labeled A3, where the channels are blue dots. Credit: OIST. Figure 2 (right): This diagram shows the new model that Professor Takahashi and his collaborators have proposed. Circles are vesicles filled with blue neurotransmitters, and the smaller grey circles are voltage-gated channels. Instead of measuring from the vesicle to the center of the channel cluster (green line), Takahashi suggests measuring to the perimeter of the channel cluster (red line). The difference is that measuring to the center varies with the size of the cluster, whereas measuring to the perimeter will always describe the closest channel to the vesicle. Credit: OIST)

Tackling Neurotransmission Precision

Behind all motor, sensory and memory functions, calcium ions are in the brain, making those functions possible. Yet neuroscientists do not entirely understand how fast calcium ions reach their targets inside neurons, and how that timing changes neural signaling. Researchers at the Okinawa Institute of Science and Technology Graduate University have determined how the distance from calcium channels to calcium sensors on vesicles affects a neuron’s signaling precision and efficacy. In international collaboration with research institutes such as the Pasteur Institute and the Institute of Science and Technology Austria, Professor Tomoyuki Takahashi and the Cellular and Molecular Synaptic Function Unit described the locations of voltage-gated calcium channels, which allow calcium ions to enter into the neuron, triggering vesicles to release neurotransmitters, signaling to the next neuron. This research, to be published the January 7, 2015 issue of Neuron, illuminates decades of mystery behind the precision and efficacy of neurotransmitter release, suggesting how signaling changes as an animal matures.

After an electrical spike, or an instantaneous change in voltage, travels through the neuron, it reaches the presynaptic terminal. The presynaptic terminal is an area facing the synaptic cleft, or the gap between one neuron and the next. The electrical spike triggers voltage-gated calcium channels to open, allowing calcium ions to enter the presynaptic terminal. The calcium ions then diffuse locally around the channels and encounter synaptic vesicles, small packages of neurotransmitters, which are signaling molecules. The calcium ions interact with sensor proteins on the vesicle, triggering the vesicles to fuse with the presynaptic terminal membrane, and releasing neurotransmitters into the synaptic cleft toward the next neuron.

Yet researchers have never fully grasped how calcium travels from gated channel to vesicle. Some researchers argued that the channels were spread across the active zone of the presynaptic terminal, while others argued that a ring of gated channels surrounded each vesicle. Therefore, Takahashi’s project began with an electron microscope technique, where the researchers froze the presynaptic membrane and broke it open to expose the calcium channels (Figure 1). They found that the channels existed in clusters, with a variable number of channels in each cluster.

Next, the researchers ran various tests and simulations to determine how the channel clusters impact signaling. They found that clusters with more calcium channels more effectively trigger a nearby vesicle to release neurotransmitters. Importantly, channel clusters closer to vesicles trigger neurotransmitter release more quickly and more efficiently than clusters located farther from vesicles, increasing signal precision. “The calcium sensor on vesicles need a high concentration of calcium to trigger vesicle release,” Takahashi said. “If the calcium entered from farther away, then it would diffuse into a lower concentration or bind to other proteins before reaching the calcium sensor on the vesicle.”

Takahashi and his collaborators also studied how the distance changes as their rat subjects developed, and how the distance changes affect neural signaling. As the rat aged from seven days to fourteen days, the distance between the gated channels and the vesicle shrank from 30 nanometers to 20 nanometers. “This maturation is fairly significant,” Takahashi said, explaining that the vesicles release much more quickly after calcium enters the synapse. “The signal becomes 30% faster,” he said.

Moving forward, Takahashi and his collaborators propose the perimeter release model for use in neuroscience research (Figure 2). This model establishes that calcium channels exist in clusters and that the distance from these clusters to a vesicle is significant. “If you measure the distance from the center of the cluster, then this distance depends on the size of the cluster,” Takahashi said. Therefore, the researchers propose the distance from vesicle to gated channel clusters be measured from the perimeter of the cluster, rather than the center. Distances calculated using this new model can explain how signaling precision increases during development.

“If there is anything which widens this distance,” Takahashi said, “it actually interferes with neural precision and it can interfere with memory formation.”

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A robot that makes you feel that there’s ghosts behind you?

Something I’m sure my fellow neuroscientist-to-be, sixpenceee would appreciate.

“Ghosts only exist in our minds, and we know precisely where to look for them. Patients suffering from neurological or psychiatric conditions have often reported a strange “feeling of a presence”. EPFL researchers have now succeeded in recreating this illusion in the lab.”

[Read more]