Category: Neuron


A Giant Neuron Has Been Found Wrapped Around the Entire Circumference of the Brain

By Hugo Angel,

Allen Institute for Brain Science

This could be where consciousness forms. For the first time, scientists have detected a giant neuron wrapped around the entire circumference of a mouse’s brain, and it’s so densely connected across both hemispheres, it could finally explain the origins of consciousness.

Using a new imaging technique, the team detected the giant neuron emanating from one of the best-connected regions in the brain, and say it could be coordinating signals from different areas to create conscious thought.

This recently discovered neuron is one of three that have been detected for the first time in a mammal’s brain, and the new imaging technique could help us figure out if similar structures have gone undetected in our own brains for centuries.

At a recent meeting of the Brain Research through Advancing Innovative Neurotechnologies initiative in Maryland, a team from the Allen Institute for Brain Science described how all three neurons stretch across both hemispheres of the brain, but the largest one wraps around the organ’s circumference like a “crown of thorns”.
You can see them highlighted in the image at the top of the page.

Lead researcher Christof Koch told Sara Reardon at Nature that they’ve never seen neurons extend so far across both regions of the brain before.
Oddly enough, all three giant neurons happen to emanate from a part of the brain that’s shown intriguing connections to human consciousness in the past – the claustrum, a thin sheet of grey matter that could be the most connected structure in the entire brain, based on volume.

This relatively small region is hidden between the inner surface of the neocortex in the centre of the brain, and communicates with almost all regions of cortex to achieve many higher cognitive functions such as

  • language,
  • long-term planning, and
  • advanced sensory tasks such as
  • seeing and
  • hearing.

Advanced brain-imaging techniques that look at the white matter fibres coursing to and from the claustrum reveal that it is a neural Grand Central Station,Koch wrote for Scientific American back in 2014. “Almost every region of the cortex sends fibres to the claustrum.”

The claustrum is so densely connected to several crucial areas in the brain that Francis Crick of DNA double helix fame referred to it a “conductor of consciousnessin a 2005 paper co-written with Koch.

They suggested that it connects all of our external and internal perceptions together into a single unifying experience, like a conductor synchronises an orchestra, and strange medical cases in the past few years have only made their case stronger.

Back in 2014, a 54-year-old woman checked into the George Washington University Medical Faculty Associates in Washington, DC, for epilepsy treatment.

This involved gently probing various regions of her brain with electrodes to narrow down the potential source of her epileptic seizures, but when the team started stimulating the woman’s claustrum, they found they could effectively ‘switch’ her consciousness off and on again.

Helen Thomson reported for New Scientist at the time:
When the team zapped the area with high frequency electrical impulses, the woman lost consciousness. She stopped reading and stared blankly into space, she didn’t respond to auditory or visual commands and her breathing slowed.

As soon as the stimulation stopped, she immediately regained consciousness with no memory of the event. The same thing happened every time the area was stimulated during two days of experiments.”

According to Koch, who was not involved in the study, this kind of abrupt and specific ‘stopping and starting‘ of consciousness had never been seen before.

Another experiment in 2015 examined the effects of claustrum lesions on the consciousness of 171 combat veterans with traumatic brain injuries.

They found that claustrum damage was associated with the duration, but not frequency, of loss of consciousness, suggesting that it could play an important role in the switching on and off of conscious thought, but another region could be involved in maintaining it.

And now Koch and his team have discovered extensive neurons in mouse brains emanating from this mysterious region.

In order to map neurons, researchers usually have to inject individual nerve cells with a dye, cut the brain into thin sections, and then trace the neuron’s path by hand.

It’s a surprisingly rudimentary technique for a neuroscientist to have to perform, and given that they have to destroy the brain in the process, it’s not one that can be done regularly on human organs.

Koch and his team wanted to come up with a technique that was less invasive, and engineered mice that could have specific genes in their claustrum neurons activated by a specific drug.

When the researchers fed the mice a small amount of the drug, only a handful of neurons received enough of it to switch on these genes,Reardon reports for Nature.

That resulted in production of a green fluorescent protein that spread throughout the entire neuron. The team then took 10,000 cross-sectional images of the mouse brain, and used a computer program to create a 3D reconstruction of just three glowing cells.

We should keep in mind that just because these new giant neurons are connected to the claustrum doesn’t mean that Koch’s hypothesis about consciousness is correct – we’re a long way from proving that yet.

It’s also important to note that these neurons have only been detected in mice so far, and the research has yet to be published in a peer-reviewed journal, so we need to wait for further confirmation before we can really delve into what this discovery could mean for humans.

But the discovery is an intriguing piece of the puzzle that could help up make sense of this crucial, but enigmatic region of the brain, and how it could relate to the human experience of conscious thought.

The research was presented at the 15 February meeting of the Brain Research through Advancing Innovative Neurotechnologies initiative in Bethesda, Maryland.

ORIGINAL: ScienceAlert

BEC CREW
28 FEB 2017

Scientists Just Found Evidence That Neurons Can Communicate in a Way We Never Anticipated

By Hugo Angel,

Andrii Vodolazhskyi/Shutterstock.com

A new brain mechanism hiding in plain sight. Researchers have discovered a brand new mechanism that controls the way nerve cells in our brain communicate with each other to regulate learning and long-term memory.

The fact that a new brain mechanism has been hiding in plain sight is a reminder of how much we have yet to learn about how the human brain works, and what goes wrong in neurodegenerative disorders such as Alzheimer’s and epilepsy.

These discoveries represent a significant advance and will have far-reaching implications for the understanding of 

  • memory, 
  • cognition, 
  • developmental plasticity, and 
  • neuronal network formation and stabilisation,”  

said lead researcher Jeremy Henley from the University of Bristol in the UK.

We believe that this is a groundbreaking study that opens new lines of inquiry which will increase understanding of the molecular details of synaptic function in health and disease.

The human brain contains around 100 billion nerve cells, and each of those makes about 10,000 connections – known as synapses – with other cells.

That’s a whole lot of connections, and each of them is strengthened or weakened depending on different brain mechanisms that scientists have spent decades trying to understand.

Until now, one of the best known mechanisms to increase the strength of information flow across synapses was known as LTP, or long-term potentiation.

LTP intensifies the connection between cells to make information transfer more efficient, and it plays a role in a wide range of neurodegenerative conditions –  

  • too much LTP, and you risk disorders such as epilepsy,  
  • too little, and it could cause dementia or Alzheimer’s disease.
As far as researchers were aware, LTP is usually controlled by the activation of special proteins called NMDA receptors.

But now the UK team has discovered a brand new type of LTP that’s regulated in an entirely different way.

After investigating the formation of synapses in the lab, the team showed that this new LTP mechanism is controlled by molecules known as kainate receptors, instead of NMDA receptors.

These data reveal a new and, to our knowledge, previously unsuspected role for postsynaptic kainate receptors in the induction of functional and structural plasticity in the hippocampus,the researchers write in Nature Neuroscience.

This means we’ve now uncovered a previously unexplored mechanism that could control learning and memory.

Untangling the interactions between the signal receptors in the brain not only tells us more about the inner workings of a healthy brain, but also provides a practical insight into what happens when we form new memories,said one of the researchers, Milos Petrovic from the University of Central Lancashire.

If we can preserve these signals it may help protect against brain diseases.

Not only does this open up a new research pathway that could lead to a better understanding of how our brains work, but if researchers can find a way to target these new pathways, it could lead to more effective treatments for a range of neurodegenerative disorders.

It’s still early days, and the discovery will now need to be verified by independent researchers, but it’s a promising new field of research.

This is certainly an extremely exciting discovery and something that could potentially impact the global population,said Petrovic.

The research has been published in Nature Neuroscience.

ORIGINAL: IFLScience

By FIONA MACDONALD
20 FEB 2017

A Scale-up Synaptic Supercomputer (NS16e): Four Perspectives

By Hugo Angel,

Today, Lawrence Livermore National Lab (LLNL) and IBM announce the development of a new Scale-up Synaptic Supercomputer (NS16e) that highly integrates 16 TrueNorth Chips in a 4×4 array to deliver 16 million neurons and 256 million synapses. LLNL will also receive an end-to-end software ecosystem that consists of a simulator; a programming language; an integrated programming environment; a library of algorithms as well as applications; firmware; tools for composing neural networks for deep learning; a teaching curriculum; and cloud enablement. Also, don’t miss the story in The Wall Street Journal (sign-in required) and the perspective and a video by LLNL’s Brian Van Essen.
To provide insights into what it took to achieve this significant milestone in the history of our project, following are four intertwined perspectives from my colleagues:

  • Filipp Akopyan — First Steps to an Efficient Scalable NeuroSynaptic Supercomputer.
  • Bill Risk and Ben Shaw — Creating an Iconic Enclosure for the NS16e.
  • Jun Sawada — NS16e System as a Neural Network Development Workstation.
  • Brian Taba — How to Program a Synaptic Supercomputer.
The following timeline provides context for today’s milestone in terms of the continued evolution of our project.
Illustration Credit: William Risk

Research on largest network of cortical neurons to date published in Nature

By Hugo Angel,

Robust network of connections between neurons performing similar tasks shows fundamentals of how brain circuits are wired
Even the simplest networks of neurons in the brain are composed of millions of connections, and examining these vast networks is critical to understanding how the brain works. An international team of researchers, led by R. Clay Reid, Wei Chung Allen Lee and Vincent Bonin from the Allen Institute for Brain Science, Harvard Medical School and Neuro-Electronics Research Flanders (NERF), respectively, has published the largest network to date of connections between neurons in the cortex, where high-level processing occurs, and have revealed several crucial elements of how networks in the brain are organized. The results are published this week in the journal Nature.
A network of cortical neurons whose connections were traced from a multi-terabyte 3D data set. The data were created by an electron microscope designed and built at Harvard Medical School to collect millions of images in nanoscopic detail, so that every one of the “wires” could be seen, along with the connections between them. Some of the neurons are color-coded according to their activity patterns in the living brain. This is the newest example of functional connectomics, which combines high-throughput functional imaging, at single-cell resolution, with terascale anatomy of the very same neurons. Image credit: Clay Reid, Allen Institute; Wei-Chung Lee, Harvard Medical School; Sam Ingersoll, graphic artist
This is a culmination of a research program that began almost ten years ago. Brain networks are too large and complex to understand piecemeal, so we used high-throughput techniques to collect huge data sets of brain activity and brain wiring,” says R. Clay Reid, M.D., Ph.D., Senior Investigator at the Allen Institute for Brain Science. “But we are finding that the effort is absolutely worthwhile and that we are learning a tremendous amount about the structure of networks in the brain, and ultimately how the brain’s structure is linked to its function.
Although this study is a landmark moment in a substantial chapter of work, it is just the beginning,” says Wei-Chung Lee, Ph.D., Instructor in Neurobiology at Harvard Medicine School and lead author on the paper. “We now have the tools to embark on reverse engineering the brain by discovering relationships between circuit wiring and neuronal and network computations.” 
For decades, researchers have studied brain activity and wiring in isolation, unable to link the two,” says Vincent Bonin, Principal Investigator at Neuro-Electronics Research Flanders. “What we have achieved is to bridge these two realms with unprecedented detail, linking electrical activity in neurons with the nanoscale synaptic connections they make with one another.
We have found some of the first anatomical evidence for modular architecture in a cortical network as well as the structural basis for functionally specific connectivity between neurons,” Lee adds. “The approaches we used allowed us to define the organizational principles of neural circuits. We are now poised to discover cortical connectivity motifs, which may act as building blocks for cerebral network function.
Lee and Bonin began by identifying neurons in the mouse visual cortex that responded to particular visual stimuli, such as vertical or horizontal bars on a screen. Lee then made ultra-thin slices of brain and captured millions of detailed images of those targeted cells and synapses, which were then reconstructed in three dimensions. Teams of annotators on both coasts of the United States simultaneously traced individual neurons through the 3D stacks of images and located connections between individual neurons.
Analyzing this wealth of data yielded several results, including the first direct structural evidence to support the idea that neurons that do similar tasks are more likely to be connected to each other than neurons that carry out different tasks. Furthermore, those connections are larger, despite the fact that they are tangled with many other neurons that perform entirely different functions.
Part of what makes this study unique is the combination of functional imaging and detailed microscopy,” says Reid. “The microscopic data is of unprecedented scale and detail. We gain some very powerful knowledge by first learning what function a particular neuron performs, and then seeing how it connects with neurons that do similar or dissimilar things.
It’s like a symphony orchestra with players sitting in random seats,” Reid adds. “If you listen to only a few nearby musicians, it won’t make sense. By listening to everyone, you will understand the music; it actually becomes simpler. If you then ask who each musician is listening to, you might even figure out how they make the music. There’s no conductor, so the orchestra needs to communicate.
This combination of methods will also be employed in an IARPA contracted project with the Allen Institute for Brain Science, Baylor College of Medicine, and Princeton University, which seeks to scale these methods to a larger segment of brain tissue. The data of the present study is being made available online for other researchers to investigate.
This work was supported by the National Institutes of Health (R01 EY10115, R01 NS075436 and R21 NS085320); through resources provided by the National Resource for Biomedical Supercomputing at the Pittsburgh Supercomputing Center (P41 RR06009) and the National Center for Multiscale Modeling of Biological Systems (P41 GM103712); the Harvard Medical School Vision Core Grant (P30 EY12196); the Bertarelli Foundation; the Edward R. and Anne G. Lefler Center; the Stanley and Theodora Feldberg Fund; Neuro-Electronics Research Flanders (NERF); and the Allen Institute for Brain Science.
About the Allen Institute for Brain Science
The Allen Institute for Brain Science, a division of the Allen Institute (alleninstitute.org), is an independent, 501(c)(3) nonprofit medical research organization dedicated to accelerating the understanding of how the human brain works in health and disease. Using a big science approach, the Allen Institute generates useful public resources used by researchers and organizations around the globe, drives technological and analytical advances, and discovers fundamental brain properties through integration of experiments, modeling and theory. Launched in 2003 with a seed contribution from founder and philanthropist Paul G. Allen, the Allen Institute is supported by a diversity of government, foundation and private funds to enable its projects. Given the Institute’s achievements, Mr. Allen committed an additional $300 million in 2012 for the first four years of a ten-year plan to further propel and expand the Institute’s scientific programs, bringing his total commitment to date to $500 million. The Allen Institute’s data and tools are publicly available online at brain-map.org.
About Harvard Medical School
HMS has more than 7,500 full-time faculty working in 10 academic departments located at the School’s Boston campus or in hospital-based clinical departments at 15 Harvard-affiliated teaching hospitals and research institutes: Beth Israel Deaconess Medical Center, Boston Children’s Hospital, Brigham and Women’s Hospital, Cambridge Health Alliance, Dana-Farber Cancer Institute, Harvard Pilgrim Health Care Institute, Hebrew SeniorLife, Joslin Diabetes Center, Judge Baker Children’s Center, Massachusetts Eye and Ear/Schepens Eye Research Institute, Massachusetts General Hospital, McLean Hospital, Mount Auburn Hospital, Spaulding Rehabilitation Hospital and VA Boston Healthcare System.
About NERF
Neuro-Electronics Research Flanders (NERF; www.nerf.be) is a neurotechnology research initiative is headquartered in Leuven, Belgium initiated by imec, KU Leuven and VIB to unravel how electrical activity in the brain gives rise to mental function and behaviour. Imec performs world-leading research in nanoelectronics and has offices in Belgium, the Netherlands, Taiwan, USA, China, India and Japan. Its staff of about 2,200 people includes almost 700 industrial residents and guest researchers. In 2014, imec’s revenue (P&L) totaled 363 million euro. VIB is a life sciences research institute in Flanders, Belgium. With more than 1470 scientists from over 60 countries, VIB performs basic research into the molecular foundations of life. KU Leuven is one of the oldest and largest research universities in Europe with over 10,000 employees and 55,000 students.
ORIGINAL: Allen Institute
March 28th, 2016

Brain waves may be spread by weak electrical field

By Hugo Angel,

The research team says the electrical fields could be behind the spread of sleep and theta waves, along with epileptic seizure waves (Credit:Shutterstock)
Mechanism tied to waves associated with epilepsy
Researchers at Case Western Reserve University may have found a new way information is communicated throughout the brain.
Their discovery could lead to identifying possible new targets to investigate brain waves associated with memory and epilepsy and better understand healthy physiology.
They recorded neural spikes traveling at a speed too slow for known mechanisms to circulate throughout the brain. The only explanation, the scientists say, is the wave is spread by a mild electrical field they could detect. Computer modeling and in-vitro testing support their theory.
Others have been working on such phenomena for decades, but no one has ever made these connections,” said Steven J. Schiff, director of the Center for Neural Engineering at Penn State University, who was not involved in the study. “The implications are that such directed fields can be used to modulate both pathological activities, such as seizures, and to interact with cognitive rhythms that help regulate a variety of processes in the brain.
Scientists Dominique Durand, Elmer Lincoln Lindseth Professor in Biomedical Engineering at Case School of Engineering and leader of the research, former graduate student Chen Sui and current PhD students Rajat Shivacharan and Mingming Zhang, report their findings in The Journal of Neuroscience.
Researchers have thought that the brain’s endogenous electrical fields are too weak to propagate wave transmission,” Durand said. “But it appears the brain may be using the fields to communicate without synaptic transmissions, gap junctions or diffusion.
How the fields may work
Computer modeling and testing on mouse hippocampi (the central part of the brain associated with memory and spatial navigation) in the lab indicate the field begins in one cell or group of cells.
Although the electrical field is of low amplitude, the field excites and activates immediate neighbors, which, in turn, excite and activate immediate neighbors, and so on across the brain at a rate of about 0.1 meter per second.
Blocking the endogenous electrical field in the mouse hippocampus and increasing the distance between cells in the computer model and in-vitro both slowed the speed of the wave.
These results, the researchers say, confirm that the propagation mechanism for the activity is consistent with the electrical field.
Because sleep waves and theta waves–which are associated with forming memories during sleep–and epileptic seizure waves travel at about 1 meter per second, the researchers are now investigating whether the electrical fields play a role in normal physiology and in epilepsy.
If so, they will try to discern what information the fields may be carrying. Durand’s lab is also investigating where the endogenous spikes come from.
ORIGINAL: Eurkalert
14-JAN-2016

Memory capacity of brain is 10 times more than previously thought

By Hugo Angel,

Data from the Salk Institute shows brain’s memory capacity is in the petabyte range, as much as entire Web

LA JOLLA—Salk researchers and collaborators have achieved critical insight into the size of neural connections, putting the memory capacity of the brain far higher than common estimates. The new work also answers a longstanding question as to how the brain is so energy efficient and could help engineers build computers that are incredibly powerful but also conserve energy.
This is a real bombshell in the field of neuroscience,” said Terry Sejnowski from the Salk Institute for Biological Studies. “Our new measurements of the brain’s memory capacity increase conservative estimates by a factor of 10 to at least a petabyte (215 Bytes = 1000 TeraBytes), in the same ballpark as the World Wide Web.
Our memories and thoughts are the result of patterns of electrical and chemical activity in the brain. A key part of the activity happens when branches of neurons, much like electrical wire, interact at certain junctions, known as synapses. An output ‘wire’ (an axon) from one neuron connects to an input ‘wire’ (a dendrite) of a second neuron. Signals travel across the synapse as chemicals called neurotransmitters to tell the receiving neuron whether to convey an electrical signal to other neurons. Each neuron can have thousands of these synapses with thousands of other neurons.
When we first reconstructed every dendrite, axon, glial process, and synapse from a volume of hippocampus the size of a single red blood cell, we were somewhat bewildered by the complexity and diversity amongst the synapses,” says Kristen Harris, co-senior author of the work and professor of neuroscience at the University of Texas, Austin. “While I had hoped to learn fundamental principles about how the brain is organized from these detailed reconstructions, I have been truly amazed at the precision obtained in the analyses of this report.
Synapses are still a mystery, though their dysfunction can cause a range of neurological diseases. Larger synapses—with more surface area and vesicles of neurotransmitters—are stronger, making them more likely to activate their surrounding neurons than medium or small synapses.
The Salk team, while building a 3D reconstruction of rat hippocampus tissue (the memory center of the brain), noticed something unusual. In some cases, a single axon from one neuron formed two synapses reaching out to a single dendrite of a second neuron, signifying that the first neuron seemed to be sending a duplicate message to the receiving neuron.
At first, the researchers didn’t think much of this duplicity, which occurs about 10 percent of the time in the hippocampus. But Tom Bartol, a Salk staff scientist, had an idea: if they could measure the difference between two very similar synapses such as these, they might glean insight into synaptic sizes, which so far had only been classified in the field as small, medium and large.
In a computational reconstruction of brain tissue in the hippocampus, Salk scientists and UT-Austin scientists found the unusual occurrence of two synapses from the axon of one neuron (translucent black strip) forming onto two spines on the same dendrite of a second neuron (yellow). Separate terminals from one neuron’s axon are shown in synaptic contact with two spines (arrows) on the same dendrite of a second neuron in the hippocampus. The spine head volumes, synaptic contact areas (red), neck diameters (gray) and number of presynaptic vesicles (white spheres) of these two synapses are almost identical. Credit: Salk Institut
To do this, researchers used advanced microscopy and computational algorithms they had developed to image rat brains and reconstruct the connectivity, shapes, volumes and surface area of the brain tissue down to a nanomolecular level.
The scientists expected the synapses would be roughly similar in size, but were surprised to discover the synapses were nearly identical.
We were amazed to find that the difference in the sizes of the pairs of synapses were very small, on average, only about 8 percent different in size,” said Tom Bartol, one of the scientists. “No one thought it would be such a small difference. This was a curveball from nature.
Because the memory capacity of neurons is dependent upon synapse size, this eight percent difference turned out to be a key number the team could then plug into their algorithmic models of the brain to measure how much information could potentially be stored in synaptic connections.
It was known before that the range in sizes between the smallest and largest synapses was a factor of 60 and that most are small.
But armed with the knowledge that synapses of all sizes could vary in increments as little as eight percent between sizes within a factor of 60, the team determined there could be about 26 categories of sizes of synapses, rather than just a few.
Our data suggests there are 10 times more discrete sizes of synapses than previously thought,” says Bartol. In computer terms, 26 sizes of synapses correspond to about 4.7 “bits” of information. Previously, it was thought that the brain was capable of just one to two bits for short and long memory storage in the hippocampus.
This is roughly an order of magnitude of precision more than anyone has ever imagined,” said Sejnowski.
What makes this precision puzzling is that hippocampal synapses are notoriously unreliable. When a signal travels from one neuron to another, it typically activates that second neuron only 10 to 20 percent of the time.
We had often wondered how the remarkable precision of the brain can come out of such unreliable synapses,” says Bartol. One answer, it seems, is in the constant adjustment of synapses, averaging out their success and failure rates over time. The team used their new data and a statistical model to find out how many signals it would take a pair of synapses to get to that eight percent difference.
The researchers calculated that
  • for the smallest synapses, about 1,500 events cause a change in their size/ability (20 minutes) and
  • for the largest synapses, only a couple hundred signaling events (1 to 2 minutes) cause a change.
This means that every 2 or 20 minutes, your synapses are going up or down to the next size,” said Bartol. “The synapses are adjusting themselves according to the signals they receive.
From left: Terry Sejnowski, Cailey Bromer and Tom Bartol. Credit: Salk Institute
Our prior work had hinted at the possibility that spines and axons that synapse together would be similar in size, but the reality of the precision is truly remarkable and lays the foundation for whole new ways to think about brains and computers,” says Harris. “The work resulting from this collaboration has opened a new chapter in the search for learning and memory mechanisms.” Harris adds that the findings suggest more questions to explore, for example, if similar rules apply for synapses in other regions of the brain and how those rules differ during development and as synapses change during the initial stages of learning.
The implications of what we found are far-reaching. Hidden under the apparent chaos and messiness of the brain is an underlying precision to the size and shapes of synapses that was hidden from us.
The findings also offer a valuable explanation for the brain’s surprising efficiency. The waking adult brain generates only about 20 watts of continuous power—as much as a very dim light bulb. The Salk discovery could help computer scientists build ultra-precise but energy-efficient computers, particularly ones that employ deep learning and neural nets techniques capable of sophisticated learning and analysis, such as speech, object recognition and translation.
This trick of the brain absolutely points to a way to design better computers,”said Sejnowski. “Using probabilistic transmission turns out to be as accurate and require much less energy for both computers and brains.
Other authors on the paper were Cailey Bromer of the Salk Institute; Justin Kinney of the McGovern Institute for Brain Research; and Michael A. Chirillo and Jennifer N. Bourne of the University of Texas, Austin.
The work was supported by the NIH and the Howard Hughes Medical Institute.
ORIGINAL: Salk.edu
January 20, 2016

Scientists have discovered brain networks linked to intelligence for the first time

By Hugo Angel,

Neurons Shutterstock 265323554_1024
Ralwel/Shutterstock.com
And we may even be able to manipulate them.
For the first time ever, scientists have identified clusters of genes in the brain that are believed to be linked to human intelligence.
The two clusters, called M1 and M3, are networks each consisting of hundreds of individual genes, and are thought to influence our

  • cognitive functions, including 
  • memory, 
  • attention, 
  • processing speed, and 
  • reasoning.
Most provocatively, the researchers who identified M1 and M3 say that these clusters are probably under the control of master switches that regulate how the gene networks function. If this hypothesis is correct and scientists can indeed find these switches, we might even be able to manipulate our genetic intelligence and boost our cognitive capabilities.
“We know that genetics plays a major role in intelligence but until now haven’t known which genes are relevant,said neurologist Michael Johnson, at Imperial College London in the UK. “This research highlights some of the genes involved in human intelligence, and how they interact with each other.
The researchers made their discovery by examining the brains of patients who had undergone neurosurgery for the treatment of epilepsy. They analysed thousands of genes expressed in the brain and combined the findings with two sets of data: genetic information from healthy people who had performed IQ tests, and from people with neurological disorders and intellectual disability.
Comparing the results, the researchers discovered that some of the genes that influence human intelligence in healthy people can also cause significant neurological problems if they end up mutating.
Traits such as intelligence are governed by large groups of genes working together – like a football team made up of players in different positions,said Johnson. “We used computer analysis to identify the genes in the human brain that work together to influence our cognitive ability to make new memories or sensible decisions when faced with lots of complex information. We found that some of these genes overlap with those that cause severe childhood onset epilepsy or intellectual disability.
The research, which is reported in Nature Neuroscience, is at an early stage, but the authors believe their analysis could have a significant impact – not only on how we understand and treat brain diseases, but one day perhaps altering brainpower itself.
Eventually, we hope that this sort of analysis will provide new insights into better treatments for neurodevelopmental diseases such as epilepsy, and ameliorate or treat the cognitive impairments associated with these devastating diseases,” said Johnson. “Our research suggests that it might be possible to work with these genes to modify intelligence, but that is only a theoretical possibility at the moment – we have just taken a first step along that road.
ORIGINAL: Science Alert
PETER DOCKRILL
22 DEC 2015

Allen Institute researchers decode patterns that make our brains human

By Hugo Angel,

Each of our human brains is special, carrying distinctive memories and giving rise to our unique thoughts and actions. Most research on the brain focuses on what makes one brain different from another. But recently, Allen Institute researchers turned the question around.
Add caption
So much research focuses on the variations between individuals, but we turned that question on its head to ask, what makes us similar?” says Ed Lein, Ph.D., Investigator at the Allen Institute for Brain Science. “What is the conserved element among all of us that must give rise to our unique cognitive abilities and human traits?
Their work, published this month in Nature Neuroscience, looked at gene expression across the entire human brain and identified a surprisingly small set of molecular patterns that dominate gene expression in the human brain and appear to be common to all individuals.
Looking at the data from this unique vantage point enables us to study gene patterning that we all share,” says Mike Hawrylycz, Ph.D., Investigator at the Allen Institute for Brain Science. “We used the Allen Human Brain Atlas data to quantify how consistent the patterns of expression for various genes are across human brains, and to determine the importance of the most consistent and reproducible genes for brain function.
Despite the anatomical complexity of the brain and the complexity of the human genome, most of the patterns of gene usage across all 20,000 genes could be characterized by just 32 expression patterns. The most highly stable genes—the genes that were most consistent across all brains—include those that are associated with diseases and disorders like autism and Alzheimer’s and include many existing drug targets. These patterns provide insights into what makes the human brain distinct and raise new opportunities to target therapeutics for treating disease.
Allen Institute researchers decode patterns that make our brains human
Conserved gene patterning across human brains provide insights into health and disease
The human brain may be the most complex piece of organized matter in the known universe, but Allen Institute researchers have begun to unravel the genetic code underlying its function. Research published this month in Nature Neuroscience identified a surprisingly small set of molecular patterns that dominate gene expression in the human brain and appear to be common to all individuals, providing key insights into the core of the genetic code that makes our brains distinctly human.
“So much research focuses on the variations between individuals, but we turned that question on its head to ask, what makes us similar?” says Ed Lein, Ph.D., Investigator at the Allen Institute for Brain Science. “What is the conserved element among all of us that must give rise to our unique cognitive abilities and human traits?”
Researchers used data from the publicly available Allen Human Brain Atlas to investigate how gene expression varies across hundreds of functionally distinct brain regions in six human brains. They began by ranking genes by the consistency of their expression patterns across individuals, and then analyzed the relationship of these genes to one another and to brain function and association with disease.
Looking at the data from this unique vantage point enables us to study gene patterning that we all share,” says Mike Hawrylycz, Ph.D., Investigator at the Allen Institute for Brain Science. “We used the Allen Human Brain Atlas data to quantify how consistent the patterns of expression for various genes are across human brains, and to determine the importance of the most consistent and reproducible genes for brain function.
Despite the anatomical complexity of the brain and the complexity of the human genome, most of the patterns of gene usage across all 20,000 genes could be characterized by just 32 expression patterns. While many of these patterns were similar in human and mouse, the dominant genetic model organism for biomedical research, many genes showed different patterns in human. Surprisingly, genes associated with neurons were most conserved across species, while those for the supporting glial cells showed larger differences.
The most highly stable genes—the genes that were most consistent across all brains—include those that are associated with diseases and disorders like autism and Alzheimer’s and include many existing drug targets. These patterns provide insights into what makes the human brain distinct and raise new opportunities to target therapeutics for treating disease.
The researchers also found that the pattern of gene expression in cerebral cortex is correlated with “functional connectivity” as revealed by neuroimaging data from the Human Connectome Project. “It is exciting to find a correlation between brain circuitry and gene expression by combining high quality data from these two large-scale projects,” says David Van Essen, Ph.D., professor at Washington University in St. Louis and a leader of the Human Connectome Project.
The human brain is phenomenally complex, so it is quite surprising that a small number of patterns can explain most of the gene variability across the brain,” says Christof Koch, Ph.D., President and Chief Scientific Officer at the Allen Institute for Brain Science. “There could easily have been thousands of patterns, or none at all. This gives us an exciting way to look further at the functional activity that underlies the uniquely human brain.
This research was conducted in collaboration with the Cincinnati Children’s Hospital and Medical Center and Washington University in St. Louis.
The project described was supported by award numbers 1R21DA027644 and 5R33DA027644 from the National Institute on Drug Abuse. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Institutes of Health and the National Institute on Drug Abuse.

About the Allen Institute for Brain Science
The Allen Institute for Brain Science is an independent, 501(c)(3) nonprofit medical research organization dedicated to accelerating the understanding of how the human brain works in health and disease. Using a big science approach, the Allen Institute generates useful public resources used by researchers and organizations around the globe, drives technological and analytical advances, and discovers fundamental brain properties through integration of experiments, modeling and theory. Launched in 2003 with a seed contribution from founder and philanthropist Paul G. Allen, the Allen Institute is supported by a diversity of government, foundation and private funds to enable its projects. Given the Institute’s achievements, Mr. Allen committed an additional $300 million in 2012 for the first four years of a ten-year plan to further propel and expand the Institute’s scientific programs, bringing his total commitment to date to $500 million. The Allen Institute’s data and tools are publicly available online at brain-map.org.
ORIGINAL: Allen Institute
November 16, 2015

Network of artificial neurons learns to use language

By Hugo Angel,

Neurons. Shutterstock
A network of artificial neurons has learned how to use language.
Researchers from the universities of Sassari and Plymouth found that their cognitive model, made up of two million interconnected artificial neurons, was able to learn to use language without any prior knowledge.
The model is called the Artificial Neural Network with Adaptive Behaviour Exploited for Language Learning — or the slightly catchier Annabell for short. Researchers hope Annabell will help shed light on the cognitive processes that underpin language development. 
Annabell has no pre-coded knowledge of language, and learned through communication with a human interlocutor. 
The system is capable of learning to communicate through natural language starting from tabula rasa, without any prior knowledge of the structure of phrases, meaning of words [or] role of the different classes of words, and only by interacting with a human through a text-based interface,” researchers said.
It is also able to learn nouns, verbs, adjectives, pronouns and other word classes and to use them in expressive language.” 
Annabell was able to learn due to two functional mechanisms — synaptic plasticity and neural gating, both of which are present in the human brain.

  • Synaptic plasticity: refers to the brain’s ability to increase efficiency when the connection between two neurons are activated simultaneously, and is linked to learning and memory.
  • Neural gating mechanisms: play an important role in the cortex by modulating neurons, behaving like ‘switches’ that turn particular behaviours on and off. When turned on, they transmit a signal; when off, they block the signal. Annabell is able to learn using these mechanisms, as the flow of information inputted into the system is controlled in different areas
The results show that, compared to previous cognitive neural models of language, the Annabell model is able to develop a broad range of functionalities, starting from a tabula rasa condition,” researchers said in their conclusion
The current version of the system sets the scene for subsequent experiments on the fluidity of the brain and its robustness. It could lead to the extension of the model for handling the developmental stages in the grounding and acquisition of language.
ORIGINAL: Wired – UK
13 NOVEMBER 15 

IBM’S ‘Rodent Brain’ Chip Could Make Our Phones Hyper-Smart

By admin,

At a lab near San Jose, IBM has built the digital equivalent of a rodent brain—roughly speaking. It spans 48 of the company’s experimental TrueNorth chips, a new breed of processor that mimics the brain’s biological building blocks. IBM
DHARMENDRA MODHA WALKS me to the front of the room so I can see it up close. About the size of a bathroom medicine cabinet, it rests on a table against the wall, and thanks to the translucent plastic on the outside, I can see the computer chips and the circuit boards and the multi-colored lights on the inside. It looks like a prop from a ’70s sci-fi movie, but Modha describes it differently. “You’re looking at a small rodent,” he says.
He means the brain of a small rodent—or, at least, the digital equivalent. The chips on the inside are designed to behave like neurons—the basic building blocks of biological brains. Modha says the system in front of us spans 48 million of these artificial nerve cells, roughly the number of neurons packed into the head of a rodent.
Modha oversees the cognitive computing group at IBM, the company that created these “neuromorphic” chips. For the first time, he and his team are sharing their unusual creations with the outside world, running a three-week “boot camp” for academics and government researchers at an IBM R&D lab on the far side of Silicon Valley. Plugging their laptops into the digital rodent brain at the front of the room, this eclectic group of computer scientists is exploring the particulars of IBM’s architecture and beginning to build software for the chip dubbed TrueNorth.
We want to get as close to the brain as possible while maintaining flexibility.’DHARMENDRA MODHA, IBM
Some researchers who got their hands on the chip at an engineering workshop in Colorado the previous month have already fashioned software that can identify images, recognize spoken words, and understand natural language. Basically, they’re using the chip to run “deep learning” algorithms, the same algorithms that drive the internet’s latest AI services, including the face recognition on Facebook and the instant language translation on Microsoft’s Skype. But the promise is that IBM’s chip can run these algorithms in smaller spaces with considerably less electrical power, letting us shoehorn more AI onto phones and other tiny devices, including hearing aids and, well, wristwatches.
What does a neuro-synaptic architecture give us? It lets us do things like image classification at a very, very low power consumption,” says Brian Van Essen, a computer scientist at the Lawrence Livermore National Laboratory who’s exploring how deep learning could be applied to national security. “It lets us tackle new problems in new environments.
The TrueNorth is part of a widespread movement to refine the hardware that drives deep learning and other AI services. Companies like Google and Facebook and Microsoft are now running their algorithms on machines backed with GPUs (chips originally built to render computer graphics), and they’re moving towards FPGAs (chips you can program for particular tasks). For Peter Diehl, a PhD student in the cortical computation group at ETH Zurich and University Zurich, TrueNorth outperforms GPUs and FPGAs in certain situations because it consumes so little power.
The main difference, says Jason Mars, a professor of a computer science at the University of Michigan, is that the TrueNorth dovetails so well with deep-learning algorithms. These algorithms mimic neural networks in much the same way IBM’s chips do, recreating the neurons and synapses in the brain. One maps well onto the other. “The chip gives you a highly efficient way of executing neural networks,” says Mars, who declined an invitation to this month’s boot camp but has closely followed the progress of the chip.
That said, the TrueNorth suits only part of the deep learning process—at least as the chip exists today—and some question how big an impact it will have. Though IBM is now sharing the chips with outside researchers, it’s years away from the market. For Modha, however, this is as it should be. As he puts it: “We’re trying to lay the foundation for significant change.
The Brain on a Phone
Peter Diehl recently took a trip to China, where his smartphone didn’t have access to the `net, an experience that cast the limitations of today’s AI in sharp relief. Without the internet, he couldn’t use a service like Google Now, which applies deep learning to speech recognition and natural language processing, because most the computing takes place not on the phone but on Google’s distant servers. “The whole system breaks down,” he says.
Deep learning, you see, requires enormous amounts of processing power—processing power that’s typically provided by the massive data centers that your phone connects to over the `net rather than locally on an individual device. The idea behind TrueNorth is that it can help move at least some of this processing power onto the phone and other personal devices, something that can significantly expand the AI available to everyday people.
To understand this, you have to understand how deep learning works. It operates in two stages. 
  • First, companies like Google and Facebook must train a neural network to perform a particular task. If they want to automatically identify cat photos, for instance, they must feed the neural net lots and lots of cat photos. 
  • Then, once the model is trained, another neural network must actually execute the task. You provide a photo and the system tells you whether it includes a cat. The TrueNorth, as it exists today, aims to facilitate that second stage.
Once a model is trained in a massive computer data center, the chip helps you execute the model. And because it’s small and uses so little power, it can fit onto a handheld device. This lets you do more at a faster speed, since you don’t have to send data over a network. If it becomes widely used, it could take much of the burden off data centers. “This is the future,” Mars says. “We’re going to see more of the processing on the devices.”
Neurons, Axons, Synapses, Spikes
Google recently discussed its efforts to run neural networks on phones, but for Diehl, the TrueNorth could take this concept several steps further. The difference, he explains, is that the chip dovetails so well with deep learning algorithms. Each chip mimics about a million neurons, and these can communicate with each other via something similar to a synapse, the connections between neurons in the brain.
‘Silicon operates in a very different way than the stuff our brains are made of.’
The setup is quite different than what you find in chips on the market today, including GPUs and FPGAs. Whereas these chips are wired to execute particular “instructions,” the TrueNorth juggles “spikes,” much simpler pieces of information analogous to the pulses of electricity in the brain. Spikes, for instance, can show the changes in someone’s voice as they speak—or changes in color from pixel to pixel in a photo. “You can think of it as a one-bit message sent from one neuron to another.” says Rodrigo Alvarez-Icaza, one of the chip’s chief designers.
The upshot is a much simpler architecture that consumes less power. Though the chip contains 5.4 billion transistors, it draws about 70 milliwatts of power. A standard Intel computer processor, by comparison, includes 1.4 billion transistors and consumes about 35 to 140 watts. Even the ARM chips that drive smartphones consume several times more power than the TrueNorth.
Of course, using such a chip also requires a new breed of software. That’s what researchers like Diehl are exploring at the TrueNorth boot camp, which began in early August and runs for another week at IBM’s research lab in San Jose, California. In some cases, researchers are translating existing code into the “spikes” that the chip can read (and back again). But they’re also working to build native code for the chip.
Parting Gift
Like these researchers, Modha discusses the TrueNorth mainly in biological terms. Neurons. Axons. Synapses. Spikes. And certainly, the chip mirrors such wetware in some ways. But the analogy has its limits. “That kind of talk always puts up warning flags,” says Chris Nicholson, the co-founder of deep learning startup Skymind. “Silicon operates in a very different way than the stuff our brains are made of.
Modha admits as much. When he started the project in 2008, backed by $53.5M in funding from Darpa, the research arm for the Department of Defense, the aim was to mimic the brain in a more complete way using an entirely different breed of chip material. But at one point, he realized this wasn’t going to happen anytime soon. “Ambitions must be balanced with reality,” he says.
In 2010, while laid up in bed with the swine flu, he realized that the best way forward was a chip architecture that loosely mimicked the brain—an architecture that could eventually recreate the brain in more complete ways as new hardware materials were developed. “You don’t need to model the fundamental physics and chemistry and biology of the neurons to elicit useful computation,” he says. “We want to get as close to the brain as possible while maintaining flexibility.
This is TrueNorth. It’s not a digital brain. But it is a step toward a digital brain. And with IBM’s boot camp, the project is accelerating. The machine at the front of the room is really 48 separate machines, each built around its own TrueNorth processors. Next week, as the boot camp comes to a close, Modha and his team will separate them and let all those academics and researchers carry them back to their own labs, which span over 30 institutions on five continents. “Humans use technology to transform society,” Modha says, pointing to the room of researchers. “These are the humans..
ORIGINAL: Wired
08.17.15

First almost fully-formed human brain grown in lab, researchers claim

By admin,

Research team say tiny brain could be used to test drugs and study diseases, but scientific peers urge caution as data on breakthrough kept under wraps
The tiny brain, which resembles that of a five-week-old foetus, is not conscious. Photograph: Ohio State University
An almost fully-formed human brain has been grown in a lab for the first time, claim scientists from Ohio State University. The team behind the feat hope the brain could transform our understanding of neurological disease.
Though not conscious the miniature brain, which resembles that of a five-week-old foetus, could potentially be useful for scientists who want to study the progression of developmental diseases. It could also be used to test drugs for conditions such as Alzheimer’s and Parkinson’s, since the regions they affect are in place during an early stage of brain development.
The brain, which is about the size of a pencil eraser, is engineered from adult human skin cells and is the most complete human brain model yet developed, claimed Rene Anand of Ohio State University, Columbus, who presented the work today at the Military Health System Research Symposium in Fort Lauderdale, Florida.
Scientists create lab-grown spinal cords
Previous attempts at growing whole brains have at best achieved mini-organs that resemble those of nine-week-old foetuses, although these “cerebral organoids” were not complete and only contained certain aspects of the brain. “We have grown the entire brain from the get-go,” said Anand.
Anand and his colleagues claim to have reproduced 99% of the brain’s diverse cell types and genes. They say their brain also contains a spinal cord, signalling circuitry and even a retina.
The ethical concerns were non-existent, said Anand. “We don’t have any sensory stimuli entering the brain. This brain is not thinking in any way.”
Anand claims to have created the brain by converting adult skin cells into pluripotent cells: stem cells that can be programmed to become any tissue in the body. These were then grown in a specialised environment that persuaded the stem cells to grow into all the different components of the brain and central nervous system.
According to Anand, it takes about 12 weeks to create a brain that resembles the maturity of a five-week-old foetus. To go further would require a network of blood vessels that the team cannot yet produce. “We’d need an artificial heart to help the brain grow further in development,” said Anand.
Several researchers contacted by the Guardian said it was hard to judge the quality of the work without access to more data, which Anand is keeping under wraps due to a pending patent on the technique. Many were uncomfortable that the team had released information to the press without the science having gone through peer review.
Zameel Cader, a consultant neurologist at the John Radcliffe Hospital, Oxford, said that while the work sounds very exciting, it’s not yet possible to judge its impact. “When someone makes such an extraordinary claim as this, you have to be cautious until they are willing to reveal their data.
3D-printed brain tissue
If the team’s claims prove true, the technique could revolutionise personalised medicine. “If you have an inherited disease, for example, you could give us a sample of skin cells, we could make a brain and then ask what’s going on,” said Anand.
You could also test the effect of different environmental toxins on the growing brain, he added. “We can look at the expression of every gene in the human genome at every step of the development process and see how they change with different toxins. Maybe then we’ll be able to say ‘holy cow, this one isn’t good for you.’
For now, the team say they are focusing on using the brain for military research, to understand the effect of post traumatic stress disorder and traumatic brain injuries.
ORIGINAL: The Guardian
Tuesday 18 August 2015

Scientists have built artificial neurons that fully mimic human brain cells

By admin,

They could supplement our brain function.

Researchers have built the world’s first artificial neuron that’s capable of mimicking the function of an organic brain cell – including the ability to translate chemical signals into electrical impulses, and communicate with other human cells.
These artificial neurons are the size of a fingertip and contain no ‘living’ parts, but the team is working on shrinking them down so they can be implanted into humans. This could allow us to effectively replace damaged nerve cells and develop new treatments for neurological disorders, such as spinal cord injuries and Parkinson’s disease.
Our artificial neuron is made of conductive polymers and it functions like a human neuron,” lead researcher Agneta Richter-Dahlfors from the Karolinska Institutet in Sweden said in a press release.

Agneta Richter-Dahlfors

Until now, scientists have only been able to stimulate brain cells using electrical impulses, which is how they transmit information within the cells. But in our bodies they’re stimulated by chemical signals, and this is how they communicate with other neurons.
By connecting enzyme-based biosensors to organic electronic ion pumps, Richter-Dahlfors and her team have now managed to create an artificial neuron that can mimic this function, and they’ve shown that it can communicate chemically with organic brain cells even over large distances.
The sensing component of the artificial neuron senses a change in chemical signals in one dish, and translates this into an electrical signal,said Richter-Dahlfors. “This electrical signal is next translated into the release of the neurotransmitter acetylcholine in a second dish, whose effect on living human cells can be monitored.
This means that artificial neurons could theoretically be integrated into complex biological systems, such as our bodies, and could allow scientists to replace or bypass damaged nerve cells. So imagine being able to use the device to restore function to paralysed patients, or heal brain damage.
Next, we would like to miniaturise this device to enable implantation into the human body,said Richer-Dahlfors.“We foresee that in the future, by adding the concept of wireless communication, the biosensor could be placed in one part of the body, and trigger release of neurotransmitters at distant locations.
Using such auto-regulated sensing and delivery, or possibly a remote control, new and exciting opportunities for future research and treatment of neurological disorders can be envisaged,she added.
The results of lab trials have been published in the journal Biosensors and Bioelectronics.
We’re really looking forward to seeing where this research goes. While the potential for treating neurological disorders are incredibly exciting, the artificial neurons could one day also help us to supplement our mental abilities and add extra memory storage or offer faster processing, and that opens up some pretty awesome possibilities.
ORIGINAL: Science Alert
By FIONA MACDONALD
29 JUN 2015