What the scientists are saying…
Dogs understand us – or try to
It’s not yet clear how much they actually understand, but new research has revealed that when dogs are spoken to by their owners, they do listen – and their brains process what they hear in much the same way as humans’ brains do. When people are interpreting speech, they take account of both words and intonation. A team of Hungarian scientists wanted to find out if dogs do the same – so they recruited 13 animals, and monitored their brain activity while they were played recordings of their owners speaking, using various combinations of words and tones. The team’s findings, published in the journal Science, suggest not only that the dogs were paying attention to both, but that they used the left side of their brain to work out the meaning of words, and the right side for emotion and intonation – just as humans do. It tended to be the case that their left sides only showed activity when they heard words that were meaningful to them; so while “however” triggered little brain activity, “good boy”, said in a neutral tone, lit up the left side. And when said in a warm tone, it lit up the right side too – as well as their brain’s reward centre. “Both what we say and how we say it matters to dogs,” said Attila Andics, a research fellow at Eötvös Loránd University in Budapest.
Is ME a form of hibernation?
Chronic fatigue syndrome – also known as ME – may be caused by the body going into a state of semi-hibernation, a new study has suggested. Some 250,000 people in Britain are believed to suffer from ME, which causes persistent and overwhelming exhaustion, can strike suddenly and has no clear cause – though theories about it abound. The latest was put forward by a team in the US, who were working on a project to find a reliable diagnostic test for the syndrome, and so set out to identify its chemical markers (by-products of chemical reactions in the cells). By screening blood plasma from 85 people, about half of whom had ME, they identified 20 such markers – which turned out to match markers found in nematode worms when they are in a hibernation-like state called “dauer”. In this state, which is a response to a stressful environment, the worm’s metabolism dramatically slows, making life possible, but little else. The scientists thus theorise that ME may occur when the metabolism overreacts to environmental stress, sending the body into survival mode.
New hope for Alzheimer’s drug
Scientists working on a new treatment for Alzheimer’s have described the results of their latest trial as the most exciting in 25 years. The trial, into the effects of an antibody drug called aducanumab, involved 165 people in the very early stages of Alzheimer’s, who were given either the antibody or a placebo, over a 54-week period. In all cases, patients given the drug showed a reduction in the levels of the amyloid plaques which build up in the brains of Alzheimer’s sufferers; in those given the highest dose, the plaques all but disappeared. “Compared to other studies published in the past, the effect size of this drug is unprecedented,” said research team member Professor Roger Nitsch, of the University of Zurich. There were also indications that the patients’ cognitive decline had slowed. “This is the best news that we have had in our 25 years,” said Dr Alfred Sandrock, from biotech firm Biogen, which is trying to develop the drug. However, independent experts cautioned that it remains unclear if amyloid plaques cause the symptoms of Alzheimer’s, or are merely a by-product of the disease, and noted that this trial was a small one, with a high drop-out rate. Much larger phase-three trials are now under way and will run until at least 2020.
Ancient Lucy “fell out of a tree”
Lucy is known to have died 3.2 million years ago; now scientists think they know how. CT scans of the early hominid’s fossilised bones – a remarkably complete set found in Ethiopia in 1974 – show fractures consistent with a long vertical fall. As her remains were uncovered on what was a forested plain, the researchers suggest that she most likely fell out of a tree. The finding is of more than curiosity value: it adds weight to the theory that her species – Australopithecus afarensis – was at least partially tree-dwelling. Lucy and her kin had lost the ape-like feet seen in earlier hominids, but had strong upper bodies suitable for climbing.