Brain and behaviour: Trust in a bottle? (pp673-676; N&V)
Just imagine if you could bottle trust, ready to be unleashed the next time you want someone to lend you some money. Well researchers have done just that, having come up with a potion that, when sniffed, makes people more inclined to trust someone else to look after their cash.
The key chemical is oxytocin, a neuropeptide molecule that is known to promote social interactions such as pair bonding in animals, say Ernst Fehr and his colleagues, who report the discovery in this week's Nature. They studied people playing a trust game in which an 'investor' could choose how many credits to hand over to a 'trustee', who would then decide how much to hand back after the stake had been quadrupled in size.
Investors were more trusting after inhaling oxytocin, the researchers found. Moreover, this effect was no longer seen when the trustee was replaced with a computer, showing that oxytocin functions to promote social interaction rather than simply making people more likely to take risks. "The finding opens up possibilities for investigating conditions in which trust is either diminished, as in autism, or augmented," comments Antonio Damasio in a related News and Views article.
Ernst Fehr (University of Zurich, Switzerland)
Tel: +41 44 634 3709; E-mail: [email protected]
Antonio Damasio (University of Iowa, IA, USA)
Tel: +1 319 356 4296; E-mail: [email protected]
 Astrophysics: Simulating the Universe (pp629-636; N&V)
The biggest-ever simulation of the Universe's growth, published in this week's Nature, follows the growth of galaxies and clusters under the influence of the mysterious stuff called dark matter. Scientists believe that dark matter helps to pull galaxies into the shapes we see today.
Volker Springel and colleagues from the Virgo Consortium have simulated how ten billion points of dark matter affect the Universe's evolution from just a few hundred million years after the Big BangThis allowed the scientists to study how structures in the Universe change and grow over billions of years.
For example, the simulation shows that galaxies with supermassive central black holes can plausibly form early enough to host the first known quasars. Some critics of dark matter theories have doubted whether they could explain how these quasars formed so quickly after the Big Bang.
"This gives us the most detailed and accurate theoretical predictions so far of the properties of galaxies and quasars, from the dawn of cosmic time to the present day," says Nickolay Gnedin in a related News and Views article.
Volker Springel (Max Planck Institute for Astrophysics, Garching near Munich, Germany)
Tel: +49 89 3000 2238; E-mail: [email protected]
Nickolay Gnedin (University of Colorado, Boulder, CO, USA)
Tel: +1 303 492 4881; E-mail: [email protected]
 Palaeontology: New dinosaur refuses to stick its neck out (pp670-672)
The discovery of a new plant-eating dinosaur from the Late Jurassic period has turned the trend for long necks in these creatures on its head. The dinosaur, which was found in modern-day Patagonia in South America, has a short neck and body, despite being related to such long-necked giants as Diplodocus.
The dinosaur, which belongs to a group called the dicraeosaurids, is less than ten metres long, with a short, stubby neck. Unlike its relatives that could reach high into the trees to maximize their food intake, the new creature appears to be adapted for browsing near the ground. More primitive dicraeosaurids have longer necks, suggesting that this feature may be a specialized adaptation.
The discovery shows that Late Jurassic plant eaters may have been more diverse in their feeding styles than experts had realized, say Oliver Rauhut and colleagues, who unveil the finding in this week's Nature. What's more, the species' closest known relative comes from Africa, hinting that these dinosaurs spread rapidly across the continents of the Southern Hemisphere after they broke away from those in the north during the Jurassic.
Oliver Rauhut (Bavarian State Collection for Palaeontology and Geology, Munich, Germany)
Tel: +49 89 2180 6645; E-mail: [email protected]
 Structural biology: Making haemoglobin stable (pp697-701)
Haemoglobin carries and delivers oxygen to tissues and organs in animals. In humans, the protein contains two alpha- and two beta-chains, each containing haem, a pigment that carries oxygen. Free alpha-haemoglobin is unstable and tends to unfold, causing release of haem and iron, which cause cellular damage. These effects are thought to contribute to the pathology of severe blood disorders such as beta-thalassemia. In red blood cells the alpha-haemoglobin-stabilizing protein (AHSP) binds to the alpha-chain and prevents its precipitation. Despite tentative clues revealed by previous work, the exact molecular mechanism by which AHSP achieved this was unclear.
Now, a study appearing in this week's Nature describes a novel structure of AHSP bound to alpha-haemoglobin. Yigong Shi and colleagues reveal that AHSP binding induces structural rearrangements in alpha-haemoglobin that prevent haem loss, thereby protecting cells from damage. Their work should help to shed light on the causes of blood disorders such as beta-thalassemia.
Yigong Shi (Princeton University, Princeton, NJ, USA)
Tel: +1 609 258 6071; E-mail: [email protected]
News feature: The mystery of the vanishing brains (pp556-558)
No one could tell the Salsbury family why their daughters' brains were mysteriously vanishing. The family donated the girls organs for research after they died, hoping to identify the disease responsible. This action led in part, to major insights into human disease, according to a News Feature in this week's Nature. Studies of children with 'vanishing white matter' disease, or CACH/VWM, have opened a window on an under-appreciated aspect of our biology; one that could change the way we view and treat a host of diseases, including cancer and Alzheimer's.
CACH/VWM is an inherited disease in which part of the brain called the white matter disappears. It usually occurs in young children, who initially seem healthy. However, a number of external influences such as a fever or a bang on the head can trigger symptoms, which start with loss of muscle coordination and can end in coma and death. Sometimes the decline takes years, but it can also take a matter of days.
There is an unusually high incidence of CACH/VWM in the Netherlands, affecting one in 40,000 people. Most of those affected come from a fairly stationary population giving a team of Dutch researchers a unique opportunity to examine the genetic cause of this disease. Now the Salsburys and other families like them have the comfort of a diagnosis and the opportunity for genetic testing.
The cause of the disease 'mutations in a protein called eIF2B, found not just in the brain, but in almost every cell of the body' was surprising. eIF2B is integral in a process called translation, which has never before implicated in such a dramatic illness. This finding is causing the scientific community to re-examine the importance of translation in health and disease.
Claire Ainsworth (Senior Reporter, Nature, London)
Tel: +44 20 7843 4 E-mail: [email protected]
Please note the Salsbury family (mentioned above) are available for media requests and can be contacted via: Juliana Minsky (SurfMedia Communications, Santa Barbara, CA, USA)
Tel: +1 805 962 3700, E-mail: [email protected]
 Materials: Charged atom controls molecular current (pp658-661; N&V)
A detailed analysis of how electrical current flows through single molecules sitting on a silicon surface is unveiled in this week's Nature.
Molecular electronics is expected to help miniaturize gadgets of the future, but scientists first need to understand exactly how the flow of current through these molecules can be controlled.
Robert Wolkow and colleagues show that conduction can be controlled using the charge state of a surface atom. "This new work suggests that more effective electrostatic control could perhaps be obtained using localized charges," comments Mark Ratner in a related News and Views article.
Robert A. Wolkow (University of Alberta, Edmonton, Alberta, Canada)
Tel: +1 780 492 8980; E-mail: [email protected]
Nature insight into autoimmunity
Our immune system is an incredibly powerful weapon, capable of repelling most diseases and infections. But sometimes the body mistakenly causes the immune system to turn on itself, and the resulting 'friendly fire' can lead to a wide array of related autoimmune diseases - some with devastating effects. Nature presents our current understanding of this field in an Insight on autoimmunity this week.
Approximately 10 million US citizens suffer from autoimmune diseases, covering over 40 different illnesses, including diabetes, rheumatoid arthritis and multiple sclerosis. Many of these illnesses are difficult or impossible to cure, because the root of the problem - our own tissues - can not be eliminated. So what causes an autoimmune response in some people and not in others?
Some people inherit a combination of genetic sequences that, once triggered by external factors, causes their immune response to turn on the body's own tissues, say John Rioux and Abul Abbas. They argue that genome-wide scanning would help to identify the genetic basis for this. Since the completion of the human genome sequencing project, scientific focus has shifted to analysing the proteins encoded by our genes. Emerging genomic and proteomic technologies, as described by C. Garrison Fathman and colleagues, are likely to lead to important discoveries in autoimmune disease.
Our immune system is the body's sixth sense, say Christopher Goodnow and colleagues, with receptors capable of reacting to any incoming chemical structure imaginable. Some of these receptors recognize elements within our own body, and so mechanisms have evolved to control them - mechanisms common to humans and other mammals, which allows for testing in animal models. Another area receiving much attention is the role that regulatory T cells play, as discussed by Mitchell Kronenberg and Alexander Rudensky. These cells police the immune system, targeting and regulating the activity of pathological self-reactive cells. However, some people with autoimmune diseases might have defective regulatory T cells, leaving pathogenic T cells unchecked.
One potential way to reset the immune system in people with severe autoimmune diseases is by way of haematopoietic cell transplantation, or HCT. Megan Sykes and Boris Nikolic explain this controversial area and present a forward-looking argument for the future of this treatment. Finally, Marc Feldmann and Lawrence Steinman discuss the 'holy grail' of autoimmunity - effective antigen-specific immunotherapy.
***Please note: Author contacts to made available on the Nature press site alongside full text pdfs of articles in this supplement and the cover image for use by the media when reporting on this insight.***
 And finallyÃ�Â¦ First martian shooting star identified (p581)
On 7 March of last year, one of the cameras on Spirit, a Mars Exploration Rover, captured a streak of light across the red planet's sky. In a Brief Communication in this week's Nature, scientists show that this streak is probably the by-product of periodic meteor showers caused by a specific comet.
When a planet closes in on the orbit of a comet that makes repeated passes through the Solar System, regular meteor showers occur. Although such episodes of shooting stars are expected to occur on Mars, this is the first identification of a martian meteor and its parent comet.
Franck Selsis and colleagues measured the timing, orientation and shape of the streak's light curve to show that it probably represented a regular meteor shower from the comet Wiseman-Skiff.
Franck Selsis (CNRS, Centre de Recherche Astronomique de Lyon, France)
Tel: +33 4 72 72 87 11; E-mail: [email protected]
ALSO IN THIS ISSUEÃ�Â¦
 A resolved outflow of matter from a brown dwarf (pp652-654)
 Arctic freshwater forcing of the Younger Dryas cold reversal (pp662-665)
 Seismological constraints on a possible plume root at the core-mantle boundary (pp666-669)
 SV40-encoded microRNAs regulate viral gene expression and reduce susceptibility to
cytotoxic T cells (pp682-686)
 Insights into E3 ligase activity revealed by a SUMO-RanGAP1-Ubc9-Nup358 complex (pp687-692)
 Structural characterization of the molecular platform for type III secretion system assembly (pp702-707)
ADVANCE ONLINE PUBLICATION
***This paper will be published electronically on Nature's website on 1 June at 1800 London time / 1300 US Eastern time (which is also when the embargo lifts) as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 2 June, but at a later date.***
 SUMO-modified PCNA recruits Srs2 to prevent recombination during S phase