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12 March 2011 | NewScientist | 17 PREGNANT mothers with unbalanced diets may be more likely to bear children at risk of adult type 2 diabetes, a study in mice suggests. The experiments show that poor diet can lead to abnormal development of the pancreatic beta cells which make insulin, the hormone vital for regulating blood sugar levels. This can trigger diabetes in adulthood as the cells “wear out” sooner than usual, says Susan Ozanne of the University of Cambridge, co- leader of the team (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1019007108). Female mice fed a low-protein diet carried fetuses with reduced production of a protein called Hnf4a in their beta cells. The researchers proved that this was caused by chemical “epigenetic” Elephants can rely on a helping trunk ELEPHANTS can coordinate their behaviour in ways once thought to be limited to our nearest primate relatives. Joshua Plotnik of Emory University in Atlanta, Georgia, and his colleagues adapted an experiment originally run with chimps, in which a pair of animals can bring a platform bearing food within their grasp if both simultaneously pull on the ends of a rope threaded through it. If only one pulls the rope, it unthreads from the platform and leaves the food out of reach. The elephants learned to tug in unison with their trunks to pull the food to them (Proceedings of the National Academy of Sciences, DOI: 10.11073/pnas.1101765108). Three years ago, rooks were seen to cooperate in a similar way, suggesting that great apes are not unique in having the combination of sociality and intelligence needed to complete the task. Lack of sleep makes for a more reckless bet “I’M FEELING lucky – make it double or nothing.” After gambling the night away, this is many a high roller’s mantra. Now we know why: a single night of sleep deprivation is enough to shift a typical gambling strategy of defending against potential losses to one in which bigger risks are taken in pursuit of greater prizes. Scott Huettel at Duke University in Durham, North Carolina, kept 29 adults awake throughout the night. He then asked them to carry out a series of gambling tasks where they could manipulate their betting options, while scanning their brain using fMRI. BRUCE DAVIDSON/MAGNUM IN BRIEF Mum’s diet sows the seeds of diabetes changes to parts of the gene that codes for Hnf4a, making it less active than it should be. As a result, the beta cells “aged” prematurely even in the womb, so were relatively “old” in the newborn pups. Ozanne says that similar ageing effects have been identified in beta cells from people with type 2 diabetes, but she adds that her team have yet to prove this is linked to poor maternal diet in humans. Unlike well-rested volunteers, the sleep-deprived changed their behaviour to pursue big wins even though this meant taking greater risks. This coincided with increased brain activity in the ventromedial prefrontal cortex, an area instrumental in computing value. Following decisions that led to losses ,they also showed decreased activity in the right anterior insula, an area linked to negative emotions (The Journal of Neuroscience, DOI: 10.1523/jneurosci.4407-10.2011). “Taken together,” says Huettel, “these effects may push people toward maladaptive behaviour: seeking gains while ignoring negative consequences.” Crucially, this bias was unrelated to the volunteers’ level of alertness. So feeling fine after a sleepless night is no guarantee that you can think straight. ALZHEIMER’S disease kills brain cells vital for memory – but now we can make new ones from human embryonic stem cells. People with Alzheimer’s could one day receive transplants of the neurons to boost their memory. Basal forebrain cholinergic neurons die off early in the progress of Alzheimer’s, affecting memory. Christopher Bissonnette and his team at Northwestern University in Evanston, Illinois, decoded the genetic signals that guide these cells’ development and so were able to induce human embryonic stem cells to grow the same way. When they transplanted the neurons into mouse brain slices, the cells successfully wove into the tissue (Stem Cells, DOI: 10.1002/stem.626). Lab-grown neurons for Alzheimer’s
