It would be an advertiser’s dream: knowing the exact location in your brain that indicates whether an ad has worked, and whether you intend to buy that cat food or wear that suntan lotion. Now, some researchers claim they’ve found a region which might predict whether viewers will act on what a commercial tells them.

For a study published yesterday in The Journal of Neuroscience, researchers asked 20 participants to listen to a series of “persuasive messages.” While the test subjects listened, researchers used an fMRI to record the activity in various regions in their brains. The study was small–but researchers say that, with these 20 participants, they could determine many of these listeners’ intentions by looking at a region associated with self-consciousness, called the medial prefrontal cortex.

The subjects listened to messages covering a range of subjects, but the team, lead by Matthew Lieberman at UCLA, was really interested in a public service message about the importance of using sunscreen. Before the brain scans, researchers surveyed the participants about a variety of their behaviors, including their expected sunscreen use for the next week.

After the brain scans were complete, researchers asked about their intentions again and gave participants “goodie bags” that included sunscreen towelettes. But a surprise follow-up phone call a week later revealed that only about half of the participants had lotioned up as often as they said they would.

The researchers then went back to the scans to hunt for hints that might have predicted this “complex real world behavior,” and that’s when they teased out possible predictions in the medial prefrontal cortex. By examining the activity in that area when the listeners heard the sunscreen messages, the researchers say they could predict the real sunblock use of three-quarters of the subjects. Thus, they claim, the brain scans were better predictors of behavior than the subjects’ own projections.

Emily Falk, a coauthor of the paper, told Reuters:

“We are trying to figure out whether there is hidden wisdom that the brain contains.”

Even if their lackluster sunblock use might leave these sunny Californians at risk for skin cancer, they don’t have to worry about brainwashing quite yet. Given the variability of people, the researchers will need probably need to test their tech on more than 20 people before they can use this information to craft the perfect public service announcement, or advertisement.

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Image: flickr / candescent

In a lab at Yale University, a rat inhales. Every breath this rodent takes is a sign of important medical advances looming on the horizon, for only one of its lungs comes from the pair it was born with. The other was built in a laboratory.

This transplanted lung is the work of Thomas Petersen and a large team of US scientists. Their technique isn’t a way of growing a lung from scratch. Instead it takes an existing lung, strips away all the cells and blood vessels to leave behind a scaffold of connective tissues, and re-grows the missing cells in a vat. It’s the medical equivalent of stripping a house down to a frame of beams and struts and rebuilding the rest from scratch. The whole process only took a few days and when the reconstituted lung was transplanted into a rat, it worked.

This is important because the lungs are notoriously bad at regenerating and repairing themselves. If a person’s lungs are severely damaged, the only real solution is a lung transplant. But that’s easier said than done. The procedure is expensive, only 20% of patients at most are still alive ten years later, and the demand for donor lungs far exceeds their supply.

Peterson’s ultimate vision is to solve these problems by fitting patients with a transplanted lung grown using their own stem cells. The scaffold would come from a dead donor, or possibly even a primate or pig. Its own cells would be stripped away and the patient’s stem cells would give the scaffold a personalised makeover, seeding it with the various types of cells in the lungs. The whole process should only take around 1-2 weeks. Laura Niklason, who led the study, says, “The value here is that the resultant lung would not reject, which is the key that limits survival of lung transplant patients right now.”

The team’s latest success in rats is a proof-of-concept – it shows that the technique should eventually be possible. But as Petersen notes, there are many technical hurdles to overcome before it could ever used in humans. That achievement is still years of hard work away. “I think that 20 to 25 years is not a bad time frame,” says Niklason. “I previously developed an engineered artery that will be ready for patients next year. It was first published in 1999. If an artery takes 12 years from first report to patients, then a lung will take 20-25.”

First, the team used detergents to strip away all the cells and blood vessels from freshly harvested lungs, leaving behind the ‘extracellular matrix’. This scaffold of connective tissues keeps the lung’s physical properties, as well as its three-dimensional structure. Right down to the microscopic level, every branch was preserved. So were the structures of the alveoli, the little spheres through which our lungs exchange gas with our blood.

The complicated nature of the scaffold explains why the team ruled out the possibility of simply growing a lung from scratch. “We grow arteries from scratch all the time in my group,” says Niklason, “but lungs are harder because of the enormous surface area that is required for adequate gas exchange.” You’d need to provide a template for that surface area and a man-made material is unlikely to do the trick. “That is, technologically, a very tall order.”Other groups have tried this approach and failed to produce anything that can actually exchange gases as a real lung can. For this reason, the team decided to use nature’s template – the lung’s own matrix.

Having exposed the matrix, they marinated it in a cocktail of lung cells taken from newborn rats. The added cells stuck to the matrix in the right places and started reproducing quickly, in a way that they normally struggle to do on standard plastic surfaces. The conditions certainly helped – the team incubated the lung matrix in a ‘bioreactor’ designed to mimic the conditions inside a growing foetus. Different tubes imitated the flow of blood and air into the developing organ, with everything was maintained at just the right pressure. All of these conditions proved to be essential for getting the lungs to re-grow in the right way.

Within just four days, the lungs were once again full of alveoli, blood vessels and small airways, all containing the right types of cells. Then, the big test: Petersen transplanted four of these brand-new lungs (just the left ones) into living rats. Within seconds, the lungs became suffused with blood, which rapidly turned from dark to bright red as it started taking up oxygen. When the team took samples of blood from the major vessels, they confirmed that the new lungs were indeed exchanging gas as they were meant to.

Their biggest challenge now is to find a good source of cells to seed the empty frames they expose. The re-fitted lungs will be immediately rejected by the immune system unless Petersen can grow them using lung stem cells derived from the patients themselves. These aren’t available yet, although techniques that reprogram adult cells into stem-like ones may help to solve this problem in the future. “The stem cell biology will be the biggest hurdle,” says Niklason. “Making the cells and growing them is not so bad, but controlling their fate within the lung matrix will be a substantial issue.”

The team have already shown that the technique works on human lung samples taken from a tissue bank. But even in rats, the results are far from perfect. Chest X-rays revealed that the fresh left lungs were indeed inflating with air but to a lesser extent than the native right ones. There were also signs of minor bleeding into the airways and some clots after a few hours. The matrix had probably become slightly damaged during the process of removing its cells. These leaks will have to be addressed before the procedure can be used in the clinic, but other scientists regard them as a sign that Petersen’s group have rushed ahead too quickly.

Joaquin Cortiella, who works on lung tissue engineering at the University of Texas Medical Branch, says, “I believe that they did not wait long enough with their cultured lung before they implanted it in the animal.” His colleague Joan Nichols agrees. “The big problem with tissue engineering is that because of the clinical need very often researchers have rushed to implant tissues before they had really produced materials worthy of transplantation,” she says.

Nichols’s own own group is working with engineered tissues that are two months old, and they only plan on implanting them into animals in 4-6 months, after careful evaluation. In particular, they want to see if the lung’s blood vessels form a proper junction with the alveoli and the matrix, something that Petersen’s group haven’t established. These junctions are the places where gas exchange takes place. If they aren’t formed properly, gas will probably still diffuse through the blood vessels because the whole organ is sitting in an oxygen-rich environment, but you get blood leaks.

Nonetheless, both researchers say that the technique used to actually produce the lung was “careful, well planned and beautifully presented”. Cortiella says that it “shows the importance of using the organ’s own extracellular matrix”, while Nichols notes that it “advances our view of what a bioreactor needs to look like in order to both grow and mature lung tissue”.

And Nichols is particularly excited about the fact that other researchers are making significant headway in engineering a lung. “It is hard to make headway in a field when so few people have tried to engineer a lung,” she says. “Good science does not take place in a vacuum. You need a critical mass to move the field along.”

Lung engineering may not be a competitive field, but it’s clear that similar approaches are being tested for other organs. Just last week, another team from Massachussetts General Hospital achieved the same trick for livers, stripping them down to a scaffold, re-growing them, and transplanting them back into rats. Again, we’re a long way off from the clinic but the fact that progress is being made at all makes this a very exciting time to be alive.

Reference: Science http://dx.doi.org/10.1126/science.1189345

More on tissue engineering: Making new heart cells

Here’s the best paleontology routine I’ve heard in the last…well, I’m not sure I’ve ever heard a paleontology routine before. This guy knows his dinosaurs, cold! Just look at his contempt when an audience member shouts out “Pterosaur.” Warning: f-bombs away!

Thanks to Boing Boing

Oh, this is nice, someone is auctioning off a nice replica TARDIS from Doctor Who and it looks pretty good, and in fact OMG IT’S AN ACTUAL TARDIS FROM THE FIRST SERIES OF DOCTOR WHO SQUUUEEEEEE!

Seriously. An actual TARDIS from the show is being auctioned. It’s from 2005, and was used during the first series by Christopher Eccleston and Billie Piper. How awesome is this?

Incredibly, the expected price is less than $20,000! Who out there in BA land wants to send me a check? I’ll let you play in the TARDIS if you do^*.

Wow. If someone out there reading this does somehow manage to score this, let me know so I can come over and play. Wow.

Tip o’ the sonic screwdriver to Crunchgear and BABloggee Doug Troy.

Perhaps it’s a disservice to continue calling the oil pouring into the Gulf a spill. “Spill” makes it hard to conceptualize the estimated 60,000 barrels of oil per day blasting up from a well more than 5,000 feet below sea level. It also makes it difficult to picture how, as BP estimates, as much as 40 percent of the material “spilling” is methane gas. That methane has been largely overshadowed by the horror of oil-soaked pelicans and tar balls washing ashore, but now a survey, completed on Monday, has measured how the methane has spread.

What’s the problem with methane? The microbes that feed off it. It can create “methane seep ecosystems”–shallow food chains that eat crude oil and dissolved methane and in the process consume all available oxygen, leaving nothing for other marine life forms. Bacteria eat the methane and “ice worms” (so-called because they live around ice-like methane hydrate) eat bacteria, but nothing else eats these worms. This creates a “dead zone.”

So in short [an abundance of creatures that use] methane for food and oxygen to “breathe” will create areas where only bacteria and a few other non-life sustaining organisms can live. All others die. [San Francisco Chronicle]

John Kessler, a Texas A&M University oceanography professor, finished a ten-day exploration of the spill earlier this week, measuring levels of dissolved methane around 4,500 feet under the water’s surface from 35 different sites, the furthest seven miles from the spill.

Levels of methane in deep-ocean waters near the Deepwater Horizon oil spill are 10,000 to 100,000 times higher than normal, and in some very hot spots “we saw them approaching 1 million times above” what would be normal, says ocean chemist John Kessler. [USA Today]

Kessler’s team also measured the levels of oxygen depletion–the sign that microbes are feeding on the methane. These numbers varied.

“At some locations, we saw depletions of up to 30 percent of oxygen based on its natural concentration in the waters. At other places, we saw no depletion of oxygen in the waters. We need to determine why that is,” he told the briefing. [Reuters]

We’ll have to wait for further results to see if the dissolved methane is indeed fueling a new dead zone in the Gulf. As Science Insider reports, Kessler and David Valentine, an oceanographer at the University of California, Santa Barbara, also hope that measuring the dissolved methane may be a way to quantify the extent of the spreading oil.

Recent posts on the Gulf Oil Spill:
80beats: From Marsh Grass to Manatees: The Next Wave of Life Endangered by BP’s Oil
80beats: Obama’s Speech on the Oil Spill: What Do You Think of His “Battle Plan”?
80beats: BP to Kevin Costner: We’ll Take 32 of Your Oil Clean-up Machines
80beats: Should We Just Euthanize the Gulf’s Oil-Soaked Birds?

Image: NASA and the MODIS Rapid Response Team

36,000,000,000,000,000,000,000,000,000,000 is a big number. But that’s actually the number of microbes in the ocean. How on Earth do you comprehend that monstrous menagerie? In my new Meet the Scientist podcast, I talk to pioneering microbiologist Mitch Sogin about a major new project to census the sea’s microbial diversity. Check it out.

The weird phenomenon of blindsight—in which people take in visual information about objects without actually “seeing” them—has long intrigued scientists, and with good reason. They’ve watched people navigate obstacle courses and identify colors while being technically blind. This week, in a study in Nature, neuroscientists point to a part of the brain called the lateral geniculate nucleus (LGN) as the neural key that might make blindsight possible.

They used macaques in which the primary visual cortex had been destroyed. The monkeys’ eye-focusing movements revealed that they were “seeing” images shown at the periphery of their visual field, but only if their LGN was intact [New Scientist].

The authors refer to the LGN as the “main relay” between the retina and main visual cortex.

Other work had shown that the LGN also has projections to a number of secondary visual areas, suggesting that it may serve as a major hub in the visual system. To test this suggestion, the authors injected the LGN with a chemical that activates the receptor for a major inhibitory signaling molecule…. When the chemical is present, nerve cells receive a signal telling them to stop signaling, so this this injection has the effect of shutting the LGN down entirely [Ars Technica].

When the scientists shut down the LGN, the primates in the study didn’t experience any blindsight, as it appears no information was reaching any of their brains’ visual centers.

Related Content:
DISCOVER: What You See Is What You Don’t
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Image: iStockphoto