SciTech #ScienceSunday Digest 7 – 17th Feb 2013
Sensory neuroprostheses, RoboRat tormentor, improved optogenetics, nanotube synapses, IBM’s Watson, gene therapy for diabetes, etc.
1. Infrared Neuroprosthesis Enables Rats to Process Infrared Light with Tactile Neural Circuits.
Animals can learn to perceive otherwise invisible infrared light through a neuroprosthesis that couples the output of a head-mounted infrared sensor to their somatosensory cortex via intracortical microstimulation http://www.nicolelislab.net/?p=345. In this proof-of-concept rats were able to use this new information from the infrared sensor to help navigate environments, but were also able to maintain normal whisker sensation and utility despite the microstimulation from the infrared prosthesis being “plugged into” the same cortical circuits as the whiskers; the original tactile representation of these circuits was not displaced by this new type of visual information. The implication is that not only might sensory neuroprostheses provide the opportunity to restore normal sensory function, there is now evidence that such prostheses might expand the sensory perceptual capabilities of humans beyond normal forms and abilities. Who wouldn’t want to see in the infrared, ultraviolet, or sonar? Or hear sounds fainter than normally possible and smell scents better than a dog? Sign me up!
2. RoboRat Programmed to Torment Rats and Deliberately Induce Depression.
In order to develop better drugs to treat depression in humans, better animal models of depression are needed because current models are inadequate. So to develop a better model of depression in animals, researchers have created a robot, shaped like a large rat, that is programmed to “attack” rats by either (i) chasing, (ii) continuously attacking, or most deviously (iii) interactively attacking whenever the rat moves to a set distance http://spectrum.ieee.org/automaton/robotics/medical-robots/ratbot-beats-on-live-rats-to-make-them-depressed. Apparently the RoboRat was most successful when it constantly harassed young rats, and then intermittently harassed them again when they were older. There are of course lots of thoughts and issues that come to mind. On the one hand this seems rather sinister, but on the other this is arguably a more humane way of inducing depression than conventional means that include frequent electric shocks and “endurance” swimming / drowning risk. The goal of creating better animal models to develop better drugs has at its heart the best interests of human welfare in mind with the aim of improving the lives of millions of people suffering from depression. Hopefully they never make a RoboHuman to do a similar thing.
3. Simpler & More Effective Optogenetics Device.
Researchers have developed a polymer implant that combines microfluidic channels to deliver genetic vectors to brain cells, a waveguide to deliver light into the brain, and electrodes to record the subsequent activity of the optogenetically-engineered neurons http://spectrum.ieee.org/biomedical/diagnostics/integrated-implant-makes-it-easier-to-control-the-brain-with-light. These devices have been christened “optrodes” and they solve the very tricky problem of accurately getting individual probes for genetic vector delivery, light delivery, and electrical sensing to precisely the same tiny targeted region of the brain. Further, the new polymer device is more flexible and biocompatible than the silicon tools used for optogenetics today and subsequent tests in rats showed that the implant could turn neurons on and off as expected. Current optogenetics experiments involve a small cable exiting from the animal’s skull, but this current team has plans to integrate a light source and electronics with the implant with the goal of making the device wireless and completely implanted. How long until we all have optrodes implanted into our brains? One or two decades? Three at most?
4. An Artificial Synapse Made of Carbon Nanotubes.
Researchers have developed a carbon nanotube synapse that demonstrates the basic dynamic logic, learning, and memory functions of a biological synapse http://www.nanowerk.com/spotlight/spotid=28970.php. This synaptic architecture displayed extremely low energy consumption, which could be significantly reduced by further scaling down the device, and these carbon nanotube synapses could be integrated in a large-scale circuit to emulate the massively parallel signal processing and learning functions of a biological neural network for speech recognition, pattern recognition, statistical inference, and other intelligent behaviors. I’m guessing they’re already aware of DARPA’s SyNAPSE program. Pre- and post-synaptic spikes demonstrated the plasticity of the artificial synapse, with the synaptic strength itself able to be continuously and reversibly modified to desired analog values.
5. IBM’s Watson Demonstrates Value to Oncologists.
IBM unveiled the first commercially-focused application of the Watson-based cognitive computing system in the field of oncology http://www-03.ibm.com/press/us/en/pressrelease/40335.wss. This is the result of thousands of hours of “teaching and instruction” Watson received from clinicians and cancer experts, the acquisition of 600,000 pieces of medical evidence and two million pages from 42 medical journals and clinical trials in the field of oncology research. As an example use-case Watson can now sift through 1.5 million patient records (decades of cancer treatment history) and provide doctors evidence-based treatment options in seconds. One of the leaders of the initiative stated; “It can take years for the latest developments in oncology to reach all practice settings. The combination of transformational technologies found in Watson with our cancer analytics and decision-making process has the potential to revolutionize the accessibility of information for the treatment of cancer in communities across the country and around the world.” This Watson-based advisor is available through the cloud and is expected to be rolled out to 1,600 specialist providers this year.
6. 3D Holographic Video Images of Living Cells.
Scientists have developed a device that can create 3D images of living cells and track their reaction to various stimuli without the use of contrast dyes or fluorophores http://actu.epfl.ch/news/peering-into-living-cells/. The device combines holographic microscopy and computational image processing to observe living biological tissues at the nanoscale at sub-100nm resolutions and does not involve the use of substances that might alter or influence the behaviour of the cells. Using the technique the group was able to film the growth of a neuron and the birth of a synapse over the course of an hour and the image processing algorithms are sophisticated enough that the virtual cell can be sliced so that internal structures can be observed if desired. The group plans a spin-out company and has aspirations to develop the device to the point where such observations are possible in vivo without the need to remove tissue.
7. Self-Assembling Complex 3-Dimensional Structures.
Chemists have developed self-assembling particles that fold from a flat pre-fabricated sheet into complex 3-dimensional structures http://phys.org/news/2013-02-origami-chemistry-scholarly-video-article-video.html. The work is demonstrated as part of a full video-article that shows the two main areas of the work, (i) particles that fold up and seal their edges because of special glue-like material at the edges, and (ii) foldable structures that reconfigure in response to a stimulus. They use photolithography to etch structural designs and flexible hinges on to a 2-D surface that can then be manipulated to fold and seal or open and close. Applications for the structures range from drug delivery, sensing, remote micro-robotic surgery, and probably many other things that we can’t yet think of. The videos are well worth the watch if you get the chance.
8. Gene Therapy Cures Type 1 Diabetes.
Dogs with type 1 diabetes have been successfully cured after a single session of gene therapy that introduced a glucose sensor into muscle cells http://www.uab.es/servlet/Satellite/latest-news/news-detail/uab-researchers-cure-type-1-diabetes-in-dogs-1096476786473.html?noticiaid=1345652365690. The work was done some time ago however, and even after four years the dogs showed no recurrence of symptoms and the adeno viral vector was demonstrated as safe. The sensor comprises insulin and glucokinase genes that together are able to regulate glucose in the blood. This is also an example of advanced tissue engineering in which the essential function of an organ (in this case the pancreas) is restored despite not targeting or treating that specific organ at all – so this therapeutic approach to curing diabetes might also be applicable to other diseases of organs like the spleen for example. A wide range of other hormone therapies might be enabled with the system although we first need to see this used to cure diabetes in humans too.
9. Advances in Understanding Superconductivity.
In what is regarded as a breakthrough for developing superconductivity applications, researchers have discovered a way to efficiently stabilize tiny magnetic vortices that interfere with superconductivity (a problem that has plagued scientists trying to engineer real-world applications for decades) http://www.anl.gov/articles/vortex-pinning-could-lead-superconducting-breakthroughs. The group was able to pin down superconductivity-destroying magnetic vortices by using 50nm diameter superconducting wires in which only a single row of vortices can form and discovered that increasing the magnetic field in this case restored the superconductivity instead of destroying it. While the work was only carried out with low-temperature superconductors the team believes that the principles will also translate to high-temperature materials.
10. Spherical Nucleic Acids & DNAzymes.
Researchers have developed spherical nucleic acids that consist of densely packed, highly oriented nucleic acids arranged on the surface of a spherical nanoparticle http://phys.org/news/2013-02-conventional-nucleic-acids.html. These 15nm non-toxic structures have a range of interesting properties including (i) easily crossing the blood-brain barrier and the layers that make up skin, (ii) don’t elicit an immune response and resist degradation in the body, (iii) the sequence or code of the coating DNA strands is able to target and regulate genes. In an earlier proof-of-concept with the material the group used commercial moisturizers to deliver the particles and regulated the genes involved in skin cancer; the drug, consisting of the spherical nucleic acids penetrated the skin’s layers and selectively targeted the cancerous cells. In related news we also had DNAzymes (DNA molecules that can enzymatically split other DNA strands) coated onto gold nanoparticles and demonstrated in a successful infectious disease diagnostic application http://phys.org/news/2013-02-dnazymes-gold-nanoparticles-colorimetric-assay.html.
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