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  • richardmitnick 8:12 am on August 19, 2014 Permalink | Reply
    Tags: , Neuroscience, , The Brain   

    From Sandia Lab: “Watching neurons fire from a front-row seat” 


    Sandia Lab

    July 28, 2014
    Sue Holmes, sholmes@sandia.gov, (505) 844-6362

    They are with us every moment of every day, controlling every action we make, from the breath we breathe to the words we speak, and yet there is still a lot we don’t know about the cells that make up our nervous systems. When things go awry and nerve cells don’t communicate as they should, the consequences can be devastating. Speech can be slurred, muscles stop working on command and memories can be lost forever.

    Better understanding of how neurons and brains work could lead to new prevention, diagnostic and treatment techniques, but the brain is complex and difficult to study. If you were to hold your brain, you would likely marvel at how much it feels and moves like Jell-O. This tissue is composed of neurons and other supporting cells with tiny cell bodies, which generate electrical signals that determine how the brain and the nervous system function.

    Those signals can be recorded and measured if a suitably small electrode is in the vicinity, but that presents challenges. Brain tissue is always moving in response to the body’s movement and breathing patterns. In addition, the nerve tissue is incredibly sensitive. If disrupted by a foreign body, the cells trigger an immune response to encapsulate the intruder and barricade it from the electrical signal it’s trying to capture and understand.

    Working to develop intelligent neural interfaces

    man
    Sandia National Laboratories researcher Murat Okandan holds one of the microscale actuators that could lead to better understanding of brain function, which could help with prevention, diagnostic and treatment techniques for brain disorders. (Photo by Randy Montoya)

    That challenge led Jit Muthuswamy, an associate professor of biomedical engineering at Arizona State University, Tempe (ASU), to pursue a robotic electrode system that would seek and maintain contact with neurons of interest autonomously in a subject going through normal behavioral routines. That led him to Sandia National Laboratories.

    “We are working to develop chronic, reliable, intelligent neural interfaces that will communicate with single neurons in a variety of applications, some of which are emerging and others that are closer to market,” Muthuswamy said. “Applications like brain prostheses are critically dependent on us being able to interface and communicate with single neurons reliably over the course of a patient’s life. Such reliable neural interfaces are also critical to help us understand the dynamic changes in the wiring diagram of the brain.”

    Key to the success of that robotic approach are the microscale actuators needed to reposition the electrodes. This led Muthuswamy in 2000 to seek out Sandia engineer Murat Okandan and the unique microsystems engineering capabilities available at Sandia’s Microsystems and Engineering Sciences Applications facility.

    “The process flow we use to make these isn’t available anywhere else in the world, so the level of complexity and mechanical design space we had to design and fabricate these was immensely larger than what other researchers might have,” Okandan said. He has been working with Muthuswamy’s research team since that initial contact to find a suitable method to track individual neurons as they fire.

    Earlier probes were made of a sharpened metal wire inserted in the tissue. The closer the probe is to the neuron, the stronger the signal, so experimenters ideally try to get as close as possible without disrupting surrounding tissue. The problem is that even a thin wire is too big; such a probe can take measurements around the neuron, but is far too cumbersome to be reliable over time.

    Equally important is capturing the signals from an awake animal. Given their size and rigidity, current probes aren’t suited to gather recordings as the animal responds to its environment. Those units aren’t self-contained, so they keep the animals from moving around freely.

    Microscale key to capturing signals from awake, moving animals

    Microscale actuators and microelectrodes are critical to addressing both of those issues so probes can interact with individual nerve cells while doing minimal damage to surrounding tissue. The microscale actuators and associated packaging system developed at ASU and Sandia let a probe move autonomously in and out of the areas surrounding the cell, collecting measurements while compensating for any movement in the neuron or brain tissue.

    About the size of a thumbnail, the self-contained unit has three microelectrodes and associated micro actuators. When a current runs through the thermal actuator, it expands and pushes the microelectrodes outward over the edge of the unit, which is flat to fit against the tissue. Because the actuator is so small, it can be heated to several hundred degrees Celsius and cooled again 1,000 times per second. It takes 540 cycles to fully extend the probe, but that can be done quickly – in a second or less.

    The probes were implanted in the somatosensory cortex of rodents and rigorously tested in numerous experiments, both in acute and long-term conditions, Muthuswamy said. Animal procedures were carried out with the approval of ASU’s Institute of Animal Care and Use Committee, and experiments were done in accordance with National Institute of Health guidelines.

    Muthuswamy said the neural probes demonstrated significant improvement in the quality and reliability of the signals when the probes were moved with precision using the Sandia microactuators in response to loss of neural signals. Further, he said, adding autonomous closed-loop controls to compensate for microscale perturbations in brain tissue significantly improved the stability of neural recordings from the brain.

    Scale of this system is unique

    Thermal actuators have been used for years at Sandia and elsewhere, but the scale of this system is unique. “The idea that we could build this system to achieve multiple millimeters of total displacement out of a micron-scaled device was a significant milestone,” said Sandia engineer Michael Baker, who designed the actuator. “We used electrostatic actuators in the past, but the thermal actuator provides much higher force, which is needed to move the probe in tissue.”

    The microelectrodes are made of highly conductive polysilicon, which the team discovered has a number of advantages. It is almost metal-like in its conductivity, but durable enough for millions of cycles. It provides a signal-to-noise ratio much greater than previous wire probes and provides high-quality measurement signals.

    Muthuswamy and Okandan currently are seeking to produce richer data with resolution in the submicron range to be able to go inside cells and take measurements there. They also are working on stacking the existing neural probe chips and decreasing the spaces between probes. Muthuswamy’s Neural Microsystems lab at ASU has developed a unique stacking approach for creating three-dimensional arrays of actuated microelectrodes.

    “By building a three-dimensional array, we would have access to significantly more information, rather than just a slice,” Okandan said. “We’re very encouraged by the progress we have made, and are looking forward to building on that progress.”

    See the full article here.

    Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.
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  • richardmitnick 3:13 pm on July 28, 2014 Permalink | Reply
    Tags: , Neuroscience,   

    From Sandia Lab: “Watching neurons fire from a front-row seat” 


    Sandia Lab

    July 28, 2014
    Sue Holmes, sholmes@sandia.gov, (505) 844-6362

    They are with us every moment of every day, controlling every action we make, from the breath we breathe to the words we speak, and yet there is still a lot we don’t know about the cells that make up our nervous systems. When things go awry and nerve cells don’t communicate as they should, the consequences can be devastating. Speech can be slurred, muscles stop working on command and memories can be lost forever.

    Better understanding of how neurons and brains work could lead to new prevention, diagnostic and treatment techniques, but the brain is complex and difficult to study. If you were to hold your brain, you would likely marvel at how much it feels and moves like Jell-O. This tissue is composed of neurons and other supporting cells with tiny cell bodies, which generate electrical signals that determine how the brain and the nervous system function.

    Those signals can be recorded and measured if a suitably small electrode is in the vicinity, but that presents challenges. Brain tissue is always moving in response to the body’s movement and breathing patterns. In addition, the nerve tissue is incredibly sensitive. If disrupted by a foreign body, the cells trigger an immune response to encapsulate the intruder and barricade it from the electrical signal it’s trying to capture and understand.

    Working to develop intelligent neural interfaces

    man
    Sandia National Laboratories researcher Murat Okandan holds one of the microscale actuators that could lead to better understanding of brain function, which could help with prevention, diagnostic and treatment techniques for brain disorders. (Photo by Randy Montoya) Click on the thumbnail for a high-resolution image

    That challenge led Jit Muthuswamy, an associate professor of biomedical engineering at Arizona State University, Tempe (ASU), to pursue a robotic electrode system that would seek and maintain contact with neurons of interest autonomously in a subject going through normal behavioral routines. That led him to Sandia National Laboratories.

    “We are working to develop chronic, reliable, intelligent neural interfaces that will communicate with single neurons in a variety of applications, some of which are emerging and others that are closer to market,” Muthuswamy said. “Applications like brain prostheses are critically dependent on us being able to interface and communicate with single neurons reliably over the course of a patient’s life. Such reliable neural interfaces are also critical to help us understand the dynamic changes in the wiring diagram of the brain.”

    Key to the success of that robotic approach are the microscale actuators needed to reposition the electrodes. This led Muthuswamy in 2000 to seek out Sandia engineer Murat Okandan and the unique microsystems engineering capabilities available at Sandia’s Microsystems and Engineering Sciences Applications facility.

    “The process flow we use to make these isn’t available anywhere else in the world, so the level of complexity and mechanical design space we had to design and fabricate these was immensely larger than what other researchers might have,” Okandan said. He has been working with Muthuswamy’s research team since that initial contact to find a suitable method to track individual neurons as they fire.

    Earlier probes were made of a sharpened metal wire inserted in the tissue. The closer the probe is to the neuron, the stronger the signal, so experimenters ideally try to get as close as possible without disrupting surrounding tissue. The problem is that even a thin wire is too big; such a probe can take measurements around the neuron, but is far too cumbersome to be reliable over time.

    Equally important is capturing the signals from an awake animal. Given their size and rigidity, current probes aren’t suited to gather recordings as the animal responds to its environment. Those units aren’t self-contained, so they keep the animals from moving around freely.

    Microscale key to capturing signals from awake, moving animals

    Microscale actuators and microelectrodes are critical to addressing both of those issues so probes can interact with individual nerve cells while doing minimal damage to surrounding tissue. The microscale actuators and associated packaging system developed at ASU and Sandia let a probe move autonomously in and out of the areas surrounding the cell, collecting measurements while compensating for any movement in the neuron or brain tissue.

    About the size of a thumbnail, the self-contained unit has three microelectrodes and associated micro actuators. When a current runs through the thermal actuator, it expands and pushes the microelectrodes outward over the edge of the unit, which is flat to fit against the tissue. Because the actuator is so small, it can be heated to several hundred degrees Celsius and cooled again 1,000 times per second. It takes 540 cycles to fully extend the probe, but that can be done quickly – in a second or less.

    The probes were implanted in the somatosensory cortex of rodents and rigorously tested in numerous experiments, both in acute and long-term conditions, Muthuswamy said. Animal procedures were carried out with the approval of ASU’s Institute of Animal Care and Use Committee, and experiments were done in accordance with National Institute of Health guidelines.

    Muthuswamy said the neural probes demonstrated significant improvement in the quality and reliability of the signals when the probes were moved with precision using the Sandia microactuators in response to loss of neural signals. Further, he said, adding autonomous closed-loop controls to compensate for microscale perturbations in brain tissue significantly improved the stability of neural recordings from the brain.

    Scale of this system is unique

    Thermal actuators have been used for years at Sandia and elsewhere, but the scale of this system is unique. “The idea that we could build this system to achieve multiple millimeters of total displacement out of a micron-scaled device was a significant milestone,” said Sandia engineer Michael Baker, who designed the actuator. “We used electrostatic actuators in the past, but the thermal actuator provides much higher force, which is needed to move the probe in tissue.”

    The microelectrodes are made of highly conductive polysilicon, which the team discovered has a number of advantages. It is almost metal-like in its conductivity, but durable enough for millions of cycles. It provides a signal-to-noise ratio much greater than previous wire probes and provides high-quality measurement signals.

    Muthuswamy and Okandan currently are seeking to produce richer data with resolution in the submicron range to be able to go inside cells and take measurements there. They also are working on stacking the existing neural probe chips and decreasing the spaces between probes. Muthuswamy’s Neural Microsystems lab at ASU has developed a unique stacking approach for creating three-dimensional arrays of actuated microelectrodes.

    “By building a three-dimensional array, we would have access to significantly more information, rather than just a slice,” Okandan said. “We’re very encouraged by the progress we have made, and are looking forward to building on that progress.”

    See the full article here.

    Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.
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  • richardmitnick 8:45 am on July 9, 2014 Permalink | Reply
    Tags: , Human brain, , Neuroscience   

    From Livermore Lab: “DARPA selects Lawrence Livermore to develop world’s first neural device to restore memory” 


    Lawrence Livermore National Laboratory

    07/08/2014
    Kenneth K Ma, LLNL, (925) 423-7602, ma28@llnl.gov

    The Department of Defense’s Defense Advanced Research Projects Agency (DARPA) awarded Lawrence Livermore National Laboratory (LLNL) up to $2.5 million to develop an implantable neural device with the ability to record and stimulate neurons within the brain to help restore memory, DARPA officials announced this week.

    one
    Lawrence Livermore engineer Vanessa Tolosa holds up a silicon wafer containing micromachined implantable neural devices.

    brain
    Lawrence Livermore National Laboratory (LLNL) will develop an implantable neural device with the ability to record and stimulate neurons within the brain to help restore memory.

    The research builds on the understanding that memory is a process in which neurons in certain regions of the brain encode information, store it and retrieve it. Certain types of illnesses and injuries, including Traumatic Brain Injury (TBI), Alzheimer’s disease and epilepsy, disrupt this process and cause memory loss. TBI, in particular, has affected 270,000 military service members since 2000.

    two
    Lawrence Livermore engineers Angela Tooker and Vanessa Tolosa load silicon wafers into a metal deposition chamber during the development of neural devices.

    The goal of LLNL’s work — driven by LLNL’s Neural Technology group and undertaken in collaboration with the University of California, Los Angeles (UCLA) and Medtronic — is to develop a device that uses real-time recording and closed-loop stimulation of neural tissues to bridge gaps in the injured brain and restore individuals’ ability to form new memories and access previously formed ones.

    The research is funded by DARPA’s Restoring Active Memory (RAM) program.

    Specifically, the Neural Technology group will seek to develop a neuromodulation system — a sophisticated electronics system to modulate neurons — that will investigate areas of the brain associated with memory to understand how new memories are formed. The device will be developed at LLNL’s Center for Bioengineering.

    “Currently, there is no effective treatment for memory loss resulting from conditions like TBI,” said LLNL’s project leader Satinderpall Pannu, director of the LLNL’s Center for Bioengineering, a unique facility dedicated to fabricating biocompatible neural interfaces. “This is a tremendous opportunity from DARPA to leverage Lawrence Livermore’s advanced capabilities to develop cutting-edge medical devices that will change the health care landscape.”

    LLNL will develop a miniature, wireless and chronically implantable neural device that will incorporate both single neuron and local field potential recordings into a closed-loop system to implant into TBI patients’ brains. The device — implanted into the entorhinal cortex and hippocampus — will allow for stimulation and recording from 64 channels located on a pair of high-density electrode arrays. The entorhinal cortex and hippocampus are regions of the brain associated with memory.

    The arrays will connect to an implantable electronics package capable of wireless data and power telemetry. An external electronic system worn around the ear will store digital information associated with memory storage and retrieval and provide power telemetry to the implantable package using a custom RF-coil system.

    Designed to last throughout the duration of treatment, the device’s electrodes will be integrated with electronics using advanced LLNL integration and 3D packaging technologies. The microelectrodes that are the heart of this device are embedded in a biocompatible, flexible polymer.

    Using the Center for Bioengineering’s capabilities, Pannu and his team of engineers have achieved 25 patents and many publications during the last decade. The team’s goal is to build the new prototype device for clinical testing by 2017.

    Lawrence Livermore’s collaborators, UCLA and Medtronic, will focus on conducting clinical trials and fabricating parts and components, respectively.

    “The RAM program poses a formidable challenge reaching across multiple disciplines from basic brain research to medicine, computing and engineering,” said Itzhak Fried, lead investigator for the UCLA on this project and professor of neurosurgery and psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA and the Semel Institute for Neuroscience and Human Behavior. “But at the end of the day, it is the suffering individual, whether an injured member of the armed forces or a patient with Alzheimer’s disease, who is at the center of our thoughts and efforts.”

    LLNL’s work on the Restoring Active Memory program supports President Obama’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) initiative.

    “Our years of experience developing implantable microdevices, through projects funded by the Department of Energy (DOE), prepared us to respond to DARPA’s challenge,” said Lawrence Livermore Engineer Kedar Shah, a project leader in the Neural Technology group.

    See the full article here.

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security
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  • richardmitnick 7:31 am on May 15, 2014 Permalink | Reply
    Tags: , , Neuroscience,   

    From Sandia Lab: “The brain: key to a better computer “ 

    Sandia Lab

    May 15, 2014
    Sue Holmes, sholmes@sandia.gov, (505) 844-6362

    Your brain is incredibly well-suited to handling whatever comes along, plus it’s tough and operates on little energy. Those attributes — dealing with real-world situations, resiliency and energy efficiency — are precisely what might be possible with neuro-inspired computing.

    “Today’s computers are wonderful at bookkeeping and solving scientific problems often described by partial differential equations, but they’re horrible at just using common sense, seeing new patterns, dealing with ambiguity and making smart decisions,” said John Wagner, cognitive sciences manager at Sandia National Laboratories.

    In contrast, the brain is “proof that you can have a formidable computer that never stops learning, operates on the power of a 20-watt light bulb and can last a hundred years,” he said.

    Although brain-inspired computing is in its infancy, Sandia has included it in a long-term research project whose goal is future computer systems. Neuro-inspired computing seeks to develop algorithms that would run on computers that function more like a brain than a conventional computer.

    brain
    Sandia National Laboratories researchers are drawing inspiration from neurons in the brain, such as these green fluorescent protein-labeled neurons in a mouse neocortex, with the aim of developing neuro-inspired computing systems. Although brain-inspired computing is in its infancy, Sandia has included it in a long-term research project whose goal is future computer systems. (Photo by Frances S. Chance, courtesy of Janelia Farm Research Campus)

    “We’re evaluating what the benefits would be of a system like this and considering what types of devices and architectures would be needed to enable it,” said microsystems researcher Murat Okandan.

    Sandia’s facilities and past research make the laboratories a natural for this work: its Microsystems & Engineering Science Applications (MESA) complex, a fabrication facility that can build massively interconnected computational elements; its computer architecture group and its long history of designing and building supercomputers; strong cognitive neurosciences research, with expertise in such areas as brain-inspired algorithms; and its decades of work on nationally important problems, Wagner said.

    New technology often is spurred by a particular need. Early conventional computing grew from the need for neutron diffusion simulations and weather prediction. Today, big data problems and remote autonomous and semiautonomous systems need far more computational power and better energy efficiency.

    Neuro-inspired computers would be ideal for robots, remote sensors

    Neuro-inspired computers would be ideal for operating such systems as unmanned aerial vehicles, robots and remote sensors, and solving big data problems, such as those the cyber world faces and analyzing transactions whizzing around the world, “looking at what’s going where and for what reason,” Okandan said.

    Such computers would be able to detect patterns and anomalies, sensing what fits and what doesn’t. Perhaps the computer wouldn’t find the entire answer, but could wade through enormous amounts of data to point a human analyst in the right direction, Okandan said.

    “If you do conventional computing, you are doing exact computations and exact computations only. If you’re looking at neurocomputation, you are looking at history, or memories in your sort of innate way of looking at them, then making predictions on what’s going to happen next,” he said. “That’s a very different realm.”

    Modern computers are largely calculating machines with a central processing unit and memory that stores both a program and data. They take a command from the program and data from the memory to execute the command, one step at a time, no matter how fast they run. Parallel and multicore computers can do more than one thing at a time but still use the same basic approach and remain very far removed from the way the brain routinely handles multiple problems concurrently.

    The architecture of neuro-inspired computers would be fundamentally different, uniting processing and storage in a network architecture “so the pieces that are processing the data are the same pieces that are storing the data, and the data will be processed with all nodes functioning concurrently,” Wagner said. “It won’t be a serial step-by-step process; it’ll be this network processing everything all at the same time. So it will be very efficient and very quick.”

    Unlike today’s computers, neuro-inspired computers would inherently use the critical notion of time. “The things that you represent are not just static shots, but they are preceded by something and there’s usually something that comes after them,” creating episodic memory that links what happens when. This requires massive interconnectivity and a unique way of encoding information in the activity of the system itself, Okandan said.

    More neurosciences research opens more possibilities for brain-inspired computing

    Each neuron in a neural structure can have connections coming in from about 10,000 neurons, which in turn can connect to 10,000 other neurons in a dynamic way. Conventional computer transistors, on the other hand, connect on average to four other transistors in a static pattern.

    Computer design has drawn from neuroscience before, but an explosion in neuroscience research in recent years opens more possibilities. While it’s far from a complete picture, Okandan said what’s known offers “more guidance in terms of how neural systems might be representing data and processing information” and clues about replicating those tasks in a different structure to address problems impossible to solve on today’s systems.

    Brain-inspired computing isn’t the same as artificial intelligence, although a broad definition of artificial intelligence could encompass it.

    “Where I think brain-inspired computing can start differentiating itself is where it really truly tries to take inspiration from biosystems, which have evolved over generations to be incredibly good at what they do and very robust against a component failure. They are very energy efficient and very good at dealing with real-world situations. Our current computers are very energy inefficient, they are very failure-prone due to components failing and they can’t make sense of complex data sets,” Okandan said.

    Computers today do required computations without any sense of what the data is — it’s just a representation chosen by a programmer.

    “Whereas if you think about neuro-inspired computing systems, the structure itself will have an internal representation of the datastream that it’s receiving and previous history that it’s seen, so ideally it will be able to make predictions on what the future states of that datastream should be, and have a sense for what the information represents.” Okandan said.

    He estimates a project dedicated to brain-inspired computing will develop early examples of a new architecture in the first several years, but said higher levels of complexity could take decades, even with the many efforts around the world working toward the same goal.

    “The ultimate question is, ‘What are the physical things in the biological system that let you think and act, what’s the core essence of intelligence and thought?’ That might take just a bit longer,” he said.

    For more information, visit the 2014 Neuro-Inspired Computational Elements Workshop website.

    See the full article here.

    Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.
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