The figure above was kindly provided by Dr. Bruno Pichler at The National Institute for Medical Research in London.

Dr. Jeffrey H. Toney is an educator and a scientist whose career has spanned academia and the pharmaceutical industry. He serves as the dean of the College of Natural, Applied and Health Sciences at Kean University. He is dedicated to strengthening public appreciation of the beauty and impact of science in our daily lives. His news media publications include The Star Ledger, The New York Times as well as regular blogs at NJ Voices, OpEdNews and The Huffington Post; he has published more than 60 peer-reviewed scientific publications and holds six US patents.

ScienceBlogs.com, February 24, 2011  —  Anyone with a young daughter knows about “bedazzled.” When I first saw these images of intact, single neurons capable of generating electrical signals, “bedazzled” came to mind.

According to the paper in Nature Neuroscience:
(on which Dr. Bruno Pichler is an author) Single-cell genetic manipulation is expected to substantially advance the field of systems neuroscience. However, existing gene delivery techniques do not allow researchers to electrophysiologically characterize cells and to thereby establish an experimental link between physiology and genetics for understanding neuronal function. In the mouse brain in vivo, we found that neurons remained intact after ‘blind’ whole-cell recording, that DNA vectors could be delivered through the patch-pipette during such recordings and that these vectors drove protein expression in recorded cells for at least 7 d. To illustrate the utility of this approach, we recorded visually evoked synaptic responses in primary visual cortical cells while delivering DNA plasmids that allowed retrograde, monosynaptic tracing of each neuron’s presynaptic inputs. By providing a biophysical profile of a cell before its specific genetic perturbation, this combinatorial method captures the synaptic and anatomical receptive field of a neuron.

Figure 3: Multiple gene delivery.

(a) Native fluorescence images of a layer 5 neuron in somatosensory cortex 3 d after patching with pCAGGS-Cerulean (top right) and pCAGGS-tdTomato (50 ng μl−1 each, bottom right). Scale bars, 824 μm (left) and 20 μm (right). (b) Gallery of native fluorescence images for a layer 2/3 cell in somatosensory cortex 5 d after recording with pCAGGS-DsRed2, pCAGGS-Venus and pCAGGS-ChR2-Cerulean. Scale bar, 20 μm.

Breakthrough in Neuroscience – new method allows characterization of neuronal networks on single-cell level

An international team led by neuroscientist Troy Margrie has developed a new method, which will shape the future of cellular neuroscience. The researchers from MRC National Institute for Medical Research in London, Columbia University in New York and Max-Planck-Institute for Medical Research in Heidelberg succeeded in determining the function of individual nerve cells in the brain and identify those neurons from which a given cell receives its signals. “The new method enables us for the first time to identify a neuronal networks on the level of individual cells and characterize it functionally”, explains Ede Rancz. This study is now published in Nature Neuroscience.

A genetically modified rabies virus leads the way

The scientists combined two existing methods, “whole-cell patch clamp recording” and “monosynaptic retrograde virus tracing”. They use the patch-clamp technique to determine the exact stimuli to which a given brain cell responds. Through the glass micropipette, which is used to record electrical signals, they simultaneously inject plasmid DNA into this cell. In the vicinity of the cell they later inject a rabies virus, which is lacking proteins necessary for entering a cell and spreading through neuronal pathways. These missing proteins are provided by the plasmid DNA injected previously into the cell. Therefore, the virus can only infect this single cell and then spread across synapses to only those neurons which are exactly one step upstream in the signaling chain. There it stops because these presynaptic cells do not contain the necessary plasmid DNA, which the modified virus needs for spreading.

Cellular networks in the living organism
The plasmid DNA and the virus both produce fluorescent proteins, which are then visualized through specialized microscopes. In this way, the functionally characterized cell as well as its connected ‘neighbours’, from which the cell receives information – let them be in close proximity or in a different brain area -can be identified. As this technique can be used in a living organism, cellular networks can be identified and then subjected to further experiments. The researchers are convinced that this method opens up the door for answering a plethora of very important but previously unapproachable questions.

The original paper is available online:
http://www.nature.com/neuro/journal/vaop/ncurrent/abs/nn.2765.html
Short video clips of original microscopy images are available at:

http://www.youtube.com/watch?v=Tujh2YH6rK8

Contact:

Prof. Troy Margrie
The Division of Neurophysiology
The National Institute for Medical Research
Mill Hill
London NW7 1AA
http://www.nimr.mrc.ac.uk/research/troy-margrie/

Security

GoogleNews.com, FORBES.com, February 24, 2011, byAndy Greenberg  —  Ray Kurzweil may be the world’s most prominent techno-optimist. The 63-year old futurist and artificial intelligence guru believes, famously, that by 2045 humans will build a computer capable of replicating and storing the human mind–what he calls the “singularity”–essentially allowing our mental selves to live on indefinitely.

So perhaps it’s no surprise that Kurzweil takes an equally sunny view of cybersecurity,  in contradiction to the prevailing gloom around the threat of cyberwar and the futile arms race against cybercriminals. In fact, Kurzweil believes that the information security industry should serve as a model for addressing the sort of pandemic diseases that may result from our globalized society and the looming problem of bioterrorism. Just as the antivirus industry constantly detects new threats, takes them apart, and distributes a “cure,” he argues that our biological antivirus systems need to work in the same networked fashion at a comparable speed.

While interviewing Kurzweil last week about topics closer to his usual fare–immortality and the progress of artificial intelligence–I slipped in a question about this information security idea, which Kurzweil mentioned in passing at a talk promoting the singularity-focused film Transcendent Man earlier this month in New York.

Here’s what he told me:

If we sat back and hoped no one put out a destructive software virus, the Internet wouldn’t last very long. We have a system between all the security protocols and the antivirus software and cybersecurity companies where we’re constantly scouting for new threats. When one’s found, it’s reverse engineered, partly with human intelligence and partly witih computer intelligence, an antidote is coded, and it’s distributed virally, getting the patches to the antiviral programs. The whole system gets more sophisticated in parallel with the predators, the viruses.

It’s never something we can cross off our list. We’ll always have computer viruses. But despite the negative perception of Internet security, it’s something that works very well. No one’s taken down the Internet for any meaningful period of time.

We need a system for biological viruses that can do the same thing. And we’re working on putting one into place. I’ve been on the Army science advisory group, and involved in this issue. The U.S. Army is responsible for bioterrorism protection. They protect us from anthrax, from small pox. But what about the specter of a bioengineering lab that engineers a new virus, adds some genes to the flu virus to make it deadlier, more communicable, more stealthy?

Today we have some techniques to deal with this like rapid sequencing. We can sequence a virus in a day, while HIV took us five years. We can create an RNA-interference medication or a antigen-based vaccine very quickly. It can be tested in-silico if the FDA accepts that sort of testing. There are these ideas that could go into a rapid response system. It would never be finished. The risks would get more and more sophisticated. But thats’ the approach.

On the Internet, a virus can spread in seconds. It’s a little easier in the biological world. It takes days or weeks to spread in a meaningful way, as we saw with swine flu. That could give you time to ship these [antidotes] around the world, just as we ship the antivirus update around the Internet.

It’s a system that’s not in place yet, but it’s feasible.

Here’s the edited interview: Ray Kurzweil and Andy Greenberg…………..

For 30 years Ray Kurzweil has been preaching the artificial intelligence gospel. As computers drive cars and play Jeopardy!, are we on track to reach his cybertopia?

Andy Greenberg: You’ve predicted that by 2045 accelerating progress in technology means we’ll build a computer–the so-called singularity–powerful enough to let us upload and replicate our brains, essentially becoming immortal. Are we on schedule?

Ray Kurzweil: With regard to artificial intelligence, we’re very much on schedule. Just look at the actual tasks that AI is performing that weren’t possible three years ago. Driving a car in a busy urban situation with no driver: Google’s driverless cars have logged 140,000 miles.

IBM’s Jeopardy!-playing supercomputer Watson plays at about the level of the best human players. I predicted in the early ’80s that a computer would defeat the world chess champion by 1998. It happened in ’97. Now people say, “Of course computers can play chess. But they’ll never be able to do something as human as understand language.” Watson is harder to dismiss.

AG: You also predicted we’d have a computer capable of 20 petaflops of processing by 2009, and we’re still less than a tenth of the way there.

RK: That computer is being built now. In 2011 there will be a 20 petaflop computer, the IBM Sequoia. So on that point we’re slightly behind schedule.

AG: What do you think about the fact that China, not the U.S.,has the fastest supercomputer in the world currently?

RK: I’m not overly concerned. It’s not a zero-sum game. We all benefit from the advance of knowledge.

AG: You talk about a certain inevitability of progress toward the singularity. What drives that progress? Is it business?

RK: Money plays an important role. It’s an enabling factor, like clay to a sculptor. But we’re programmed by biological evolution to innovate. Technological innovation just continues a process that started with biological evolution.

AG: So you’d say innovation drives business more than business drives innovation?

RK: That’s definitely true.

AG: You’ve been accused of unscientific optimism.

RK: The curve of computational progress that I’ve charted since the 1890 census until now is amazingly smooth. World War I and II, the Great Depression and the recent recession, none of these things can perturb it. That’s a powerful argument, both theoretically and empirically. But optimism is more than just an attitude about the future, it’s also a self-fulfilling prophecy.

AG: You’re 63, and I’ve read you take more than 200 pills a day to extend your life in hopes of reaching the singularity. Do you still believe you’ll live forever?

RK: Well, it’s tough to ever win that bet and say, “I’ve lived forever.” It’s never forever. But we’ll get to a point fairly soon, within 15 years, where we’ll reach a tipping point, what [gerontologist] Aubrey de Grey calls “longevity escape velocity.” Life expectancy will increase faster than time passes. I’d be irrational to say that I’m sure I’ll get to the stage where I can back myself up, which is the key point that one would need to reach to live forever. That’s maybe four decades away. In general, life expectancy is a statistical phenomenon. You can still be hit by a truck tomorrow.