Nature Podcast 4 October 2007

This is a transcript of the 04th October edition of the weekly Nature Podcast. Audio files for the current show and archive episodes can be accessed from the Nature Podcast index page (http://www.nature.com/nature/podcast), which also contains details on how to subscribe to the Nature Podcast for FREE, and has troubleshooting top-tips. Send us your feedback to mailto:podcast@nature.com.

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Kerri Smith: Coming up this week, we meet some adventurous Neanderthals.

Svante Pääbo: There might be if you like Marco Polo Neanderthals that sort of made it to shine on Mongolia and I think it will be very interesting to look further to the east and far.

Adam Rutherford: And we look back on the dawn of the space age.

Doug Millard: People were waiting for the space age to start. There had been all the science fiction stuff in books and magazines and films in the Hollywood and then it suddenly happens.

Adam Rutherford: This is the Nature Podcast. I am Adam Rutherford.

Kerri Smith: And I am Kerri Smith. Later, we will be hearing from the so-called sceptical environmentalist Bjorn Lomborge, but first and it is important you stay awake during this. A new anaesthetic method has been developed. It uses a combo of two ingredients, one of which somewhat surprisingly is capsaicin better known as the compound that gives chilly peppers their kick. Authors Bruce Bean and Clifford Woolf told me how it improves on current local anaesthetics. Here is Bruce Bean. Nature 449, 607–610 (4 October 2007)

Bruce Bean: The problem with current local anaesthetics is that they inhibit the activity of all neurons, not just the neurons that mediate pain sensation, but also neurons that mediate, for example movement of muscle, neurons that mediate the action of the sympathetic nervous system, neurons that mediate non painful touch and pressure and so forth.

Kerri Smith: And your paper reports an anaesthetic that only inhibits the nociceptors, the pain receptors, what is different about it, how does that actually work?

Bruce Bean: Well, the idea was really based on using a combination of two different agents and one is an anaesthetic that only works if it is inside a nerve cell, if it gets inside a nerve cell and normally it does not get inside nerve cells, it just cannot get through the membranes of nerve cells. So, it actually, by itself, it has no effect on any nerve cells and what we did was to put that in combination with another agent that opens a kind of ion channel that is present only on pain-sensing neurons and this ion channel is the one that mediates the hot sensation of chilly peppers and the heat itself. That ion channel actually has a pore large enough that the anaesthetic molecule can go through it, get into the nerve cell, to the inside and then inhibit the sodium channels only in the pain-sensing neurons.

Kerri Smith: Clifford Woolf, what did you actually do to test this theory?

Clifford Woolf: What the first thing we did was to take sensory neurons grown in culture and to see whether we could selectively deliver a charged form of lidocaine or lignocaine, which is the most common form of local anaesthetic and when we applied this molecule called QX314, it was as predicted, totally inactive because it cannot get across the cell membrane. We then co-applied QX with capsaicin and found that this enabled the QX to get into the cell and then only blocked those neurons that had the capsaicin receptor.

Kerri Smith: And moving on from that then, how were you able to tell that this did not affect cells involved with movement?

Clifford Woolf: The experiments to show that we did not affect neurons involved in movement was done in rodents where we were able to inject the QX form of lidocaine close to a nerve and found that it produced a loss of pain sensitivity without any effect on motor function whereas if you inject lidocaine you get a temporary paralysis in the same way that patients do.

Kerri Smith: So, the rest of the movement was not affected at all by the drug?

Clifford Woolf: Right, absolutely. Not only were their motor function completely unaffected, but also they could respond to touch stimuli.

Kerri Smith: How do you envisage being used in a clinical setting then?

Bruce Bean: Well, I think one obvious one that comes to mind probably to everybody is in childbirth where what you really want to do is to inhibit the painful sensation from the pain-sensing nerves, but still allow sensation otherwise and also similarly probably in dentistry for example by limiting the block to pain-sensing nerves you would for example not block nerves from the sympathetic and parasympathetic nervous system where block of those nerves produces drooling. In these initial experiments we used off-the-shelf molecules that we knew about that are fairly well characterized. These may not be the best ones to use in a clinical setting if we were able to extend this into using it on humans and there may be some other agents that, for example, might give a longer lasting anaesthesia.

Kerri Smith: Bruce Bean and before him Clifford Woolf on anaesthetics that won't make you comfortably numb.

Adam Rutherford: Thanks Kerri. This week sees the 50th anniversary of man's first step into the Universe. Here is Geoff Brumfiel. Nature Web Focus Russian Science

Geoff Brumfiel: Fifty years ago things were pretty swelled, Dorothy Eisenhower had just been sworn into office for her second term, the Frisbee went into mass production, and singer John Lennon met a guy named Paul McCartney at a church picnic and then suddenly...[Voice -- Today, a new moon is in the sky. A 23-inch metal sphere placed in orbit by a Russian rocket. Hear an artist's conception of how the feat was accomplished...]

Geoff Brumfiel: Out of nowhere, the Soviet Union, then the greatest threat to western prosperity announced they did launch the world's first satellite.[Voice -- Second stage to go over at five thousand miles an hour...]

Chris Welch: When the Soviet Union suddenly sent out Sputnik, it was an incredible shock.

Geoff Brumfiel: Chris Welch is a rocket engineer at Kingston University in London.

Chris Welch: The western world, in particular America, thought that they were in the lead in space and that the Soviet Union was nowhere close.

Geoff Brumfiel: But after World War II, the Soviets had secretly been making great progress in their rocket program. Under the leadership of designer Sergey_Korolyov, a team of Soviet scientists built a heavily modified version of the Nazi's V2 rocket. Theirs was a massive 270-ton machine, but it was never meant to launch a satellite.

Jonathan McDowell: Sputnik was launched on a minimally modified intercontinental ballistic missile.

Geoff Brumfiel: Jonathan McDowell of the Harvard-Smithsonian Centre for Astrophysics.

Jonathan McDowell: They had plans for an improved version of the rocket, which they were going to use with more powerful engines to launch a serious scientific satellite of about a ton, but when they heard that the US Navy was planning to launch the first American scientific satellite, then they pulled out all the stops to beat it and in just a couple of months they made a stripped-down satellite Prostreishiy Sputnik, being the simplest satellite.

Geoff Brumfiel: The soviets were eager to beat the Americans, but the politicians saw little intrinsic value in the satellite itself according to historian Alexei Kojevnikov.

Alexei Kojevnikov: In running after the launch, Sputnik was seen as a little distraction of something that scientists and engineers wanted to do and receive as a reward from politicians for their good work in creating a missile.

Geoff Brumfiel: But what nobody anticipated was that the public was ready for the era of space exploration to begin. Doug Millard is space curator at London's science museum.

Doug Millard: People were waiting for the space age to start. There had been all the science fiction stuff in books and magazines and films in the Hollywood and TV and then it suddenly happens.[Voice in Russian][Voice -- you are hearing the actual signals transmitted by the Earth circling satellite, one of the great scientific feats of the age...]

Adam Rutherford: The little satellite became an overnight media sensation. Realizing what they had done, the Soviets belatedly began pouring resources into their space program and advertising it to the rest of the world.

Doug Millard: I think it really did give the Soviets some streak red that they parlayed into political alliances.

Adam Rutherford: In America, the launch of Sputnik spurred investment in Math and Science education. It also led to a massive new agency called NASA.

Alexei Kojevnikov: NASA as an institution was at the moment of its creation was often referred to as a socialistic enterprise or as a kind of a big bureaucratic government agency that was supposed to run a certain project in a centralized way by centralizing resources. That was part of the idea how in the United States they thought why and how the Soviets succeeded in their space project.

Adam Rutherford: A month after Sputnik, the Soviets launched a dog named Laika into space, that success was followed in 1961 by the launch of the first cosmonaut, Yuri Gagarin. A year later came the first female cosmonaut, Valentina Tereshkova. The US set its sights on the moon, but as America geared up for its first lunar landing, the Soviets were already losing interest in man's space flight. They were falling behind in the arms race and needed to focus on developing better ballistic missiles. When America finally landed on the moon in 1969, the space race effectively ended. Since then, those early dreams of flying beyond the moon to colonize other planets have not really materialized.

Doug Millard: What we were expecting to achieve by now and remembering films like 2001: A Space Odyssey, fully reusable space planes, it has not happened. That is disappointing.

Adam Rutherford: But the era of space exploration is not over yet says Doug Millard.

Doug Millard: People tend to assume that the space age is almost finished. It has not, of course, as all the unmanned satellites orbiting Earth, doing lots of very important jobs. There are the planetary probes exploring the Solar System; there are telescopes up there peering into the Universe. So, really space is alive and kicking. It just so happens, that maybe our expectations were raised a little bit too high.

Geoff Brumfiel: And Sputnik's legacy lives on. Next week, a Soyuz Capsule carrying astronauts from the US, Russia, Malaysia, and the European Union will launch for the international space station. The first stage of the rocket is a modified version of the same ballistic missile that carried Sputnik on its journey 50 years ago.

Adam Rutherford: Geoff Brumfiel reporting on Sputnik's 50th birthday.

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Kerri Smith: Coming up in just a moment, those Marco Polo Neanderthals, but now it's time for The Podium, each week we will be airing the opinions of a different guest speaker. This week, we give the stage to sceptical environmentalist Bjorn Lomborge.

Bjorn Lomborge: Prioritization is an integral part of life. We budget, money, and time because they are limited. In the hospital's emergency room, doctors use prioritization or triage to save lives, but we do not use prioritization when we grapple with the world's biggest problems. We know that carbon emissions cause climate change. So, activists urge us to make drastic cuts in the CO2 we pump out, yet climate change is not the only problem facing the planet, malaria, malnutrition, and HIV/AIDS claiming millions of lives right now. In an ideal world, we would have the money and the time to solve all these problems at a stroke. In real life, we do not. Pretending that we can do everything often just means that our money and attention goes to the problems with the loudest cheerleaders or the most media attention. We need to consider how far we should push a particular solution, making drastic cuts to carbon emissions, similar to making drastic cuts to the speed limits on our roads. Slowing traffic to a crawl would save millions of lives. We could wipe out almost all road deaths overnight, yet we reject such a drastic step as nonsensical because we accept that it would make modern life impossible. That does not mean we let cars go as fast as they want. As societies, we have decided on an appropriate speed limit for our highways after weighing up the benefits we get from the efficient transport of people and goods and then considering the number of accidents. Now, we need to have a discussion about carbon emission reductions. Likewise, we should be talking about what we are willing to sacrifice and what we hope to gain. I believe this discussion should not be left just to climate scientists. We all need to look at the wider picture and remember that global warming is not the only problem facing the planet. We should be asking what policies will best help the world overall. The answers might sometimes be surprising, as an example, we often hear that rising temperatures will mean more malaria. This is true. But are CO2 cuts the best way to help people? For every person saved from malaria through the curative protocol the same resource is spent on mosquito nets and medication could save 36,000 people. Just as there are many problems facing the planet there are many possible solutions to those challenges. My belief is that immediate carbon emission cuts are not the best way to respond to climate change, instead I believe we should invest heavily in the research and development of non-carbon emitting energy technologies which will give our kids and grandkids and China and India inexpensive tools to fix climate change by mid century while allowing for the continued development of human welfare.

Kerri Smith: Bjorn Lomborge, whose new book 'Cool It' was reviewed in Nature last month. If you would like to respond to The Podium or make suggestions for topics or guests, you can email us at mailto:podcast@nature.com.Music

Adam Rutherford: Just like smelly cheese and sarcasm, Neanderthals were thought to be quintessentially European, a hominid that stuck to the continent. A new study using mitochondrial DNA sequencing reveals that the Neanderthals realm was much bigger than previously thought. I am joined by Nature editor Henry Gee in the studio and by lead author of the paper Svante Pääbo on the phone from the Max-Planck Institute for Evolutionary Anthropology in Leipzig. Svante set the scene for us, before your study what were the boundaries of the Neanderthals dominion. Nature advance online publication 30 September 2007.

Svante Pääbo: So, what you traditionally will find in textbooks is that Neanderthals lived in Europe and in Western Asia pretty much where sort of Caucasians live today and what we have found is that when we go further to the East, Uzbekistan and to the Altai mountains in Southern Siberia you find bones there that contain DNA sequences that look like any Neanderthal that you would find in France or Belgium or Germany.

Adam Rutherford: And these bones were not identified as being Neanderthal bones until you did this DNA analysis.

Svante Pääbo: It was quiet debated, I think the child we analyzed from Uzbekistan most people would have believed it was a Neanderthal even if it was questioned by some, whereas 1500 kilometres further to east in Southern Siberia most people did not believe if that was a Neanderthal and what we have then done is to extract DNA and look at DNA sequences and compare it to the 13 Neanderthals from which we already had DNA sequences and we find that they are very typical Neanderthals.

Adam Rutherford: So, the locations of these bones which are in Southern Siberia, do you think this is actually going to be the eastern most boundary of where the Neanderthals lived?

Svante Pääbo: Since we now saw, if you like, easily have been able to extend their range so much further to the east I would be surprised if this is the eastern most point as we say in our paper. It sort of sets a stage for that there might be, if you like, Marco Polo Neanderthals that sort of made it to China and Mongolia and I think it will be very interesting to look further to the east and the south from this point.

Adam Rutherford: Okay, Henry, if I could turn to you, this is another piece in the Neanderthal puzzle suggesting that our understanding of this species is far from comprehensive?

Henry Gee: Yes, I think professor Paabo is right. The new findings in Southern Siberia about 2000 kilometres further east of the previous Neanderthal eastern most record suggests that there is a lot more to be found in Central Asia and eastern Asia whereas most people have concentrated in Europe because that is where the archaeology has been done, historically that is where most Neanderthals have been found and that does not mean that that is where they lived only. It could be that we have not really looked hard enough in other places.

Adam Rutherford: So, as we go further east and we use more and more molecular biology techniques, what other revelations are there going to be about other human ancestors?

Henry Gee: This is a very exciting question. We know very, very little about the evolution of human beings in eastern Asia. There are all sorts of very odd bits and pieces from China over a very wide time period and a very wide area. They have been historically very hard to place within the general picture of human evolution particularly at the time of the Neanderthals which is very much a Europe-centred discipline so far. So, perhaps some of these molecular biology techniques could be applied to some of the eastern Asian fossils and they may pick up some early Neanderthal signals. This could tell us all sort of exciting things there could be. Now, this is really flying the kite and you know, perhaps Neanderthals originated in eastern Asia. We have no idea. The question of the origin of the Neanderthals is an open question as well as their extinction. I think this opens up a large number of possibilities. This is one very exciting research in the future.

Adam Rutherford: So, exciting times for paleoanthropology, thanks Henry Gee and Svante Pääbo; that is it from this week's pod.

Kerri Smith: Remember you can drop us a line at mailto:podcast@nature.com with any feedback or suggestions for The Podium.

Adam Rutherford: All your ideas for sounds of science this week on its 50th birthday, here is Sputnik's first ever transmission. I am Adam Rutherford.

Kerri Smith: And I am Kerri Smith. Thanks for listening.

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