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Nicotine tied to Alzheimer's risk
Benedicte Kurzen/VII Mentor Program
IN BRIEF Nicotine may raise Alzheimer’s risk SMOKING could predispose people to dementia, not protect them as had been suggested. Rats with brain plaques develop further symptoms of Alzheimer’s when given nicotine. In Alzheimer’s disease, the brain becomes riddled with amyloid plaques and tangles of tau proteins. Low doses of nicotine reduce the number of plaques in rats, yet little was known about the effect on the protein tangles. To find out, Yan-Jiang Wang’s team at Third Military Medical University in Chongqing, China, injected plaques into the brains of healthy rats and gave some a smoker’s daily dose of nicotine for two weeks, others nothing. All the rats showed early signs of tau tangles and had difficulty navigating a maze, but the rats on nicotine were worse off (European Journal of Pharmacology, DOI: 10.1016/j.ejphar.2010.03.029).
People pick up pepper virus
New-found hominid cousin is a brain teaser NOT only have we found a long-lost cousin, but it now appears that the skull of newly unveiled Australopithecus sediba contains a print of its brain. The skull of the young male australopithecine, unearthed in South Africa, is so well preserved that early analysis of X-ray tomographic images taken at the European Synchrotron Research Facility (ESRF) in Grenoble, France, reveals that the brain may have left its imprint on sediment filling the skull. Though tantalising, Paul Tafforeau, a palaeontologist at the ESRF, is cautious about what new insights the imprint may yield. Brain or no brain, A. sediba is significant because its anatomy is the most similar of any australopithecine yet found to the true humans that evolved into us. Two partial skeletons, one of a male child aged 9 to 13 years and the other of an adult female, were dug up in the Cradle of
14 | NewScientist | 17 April 2010
Humankind world heritage site near Johannesburg by Lee Berger of the University of the Witwatersrand in Johannesburg and colleagues. They are between 1.95 and 1.78 million years old (Science, vol 328, p 195). Though its physical features are the most human-like of any australopithecine yet discovered, A. sediba is hundreds of thousands of years younger than the oldest fossils assigned to the genus Homo, meaning it is unlikely to be our direct ancestor. The juvenile is the most complete australopithecine skeleton yet found from the period: it includes much of the skull and large parts of an arm, leg and pelvis. Both hominids were about 1.2 metres tall, with ape-sized brains. “This is the most human-like australopithecine yet discovered,” says Chris Stringer of the Natural History Museum in London, who was not involved in the study.
COULD a plant virus have found a way to infect humans? It has always been assumed that plant viruses cannot infect animals, and vice versa. But now Didier Raoult at the University of the Mediterranean in Marseille, France, and his team have found RNA from the pepper mild mottle virus in the faeces of 7 per cent of the 304 adults they tested. Those with the virus were more likely to report fever, abdominal pain and itching than those without it (PLoS One, DOI: 10.1371/journal. pone.0010041). The team is now looking for direct proof that the virus causes these symptoms. But Robert Garry at Tulane University in New Orleans, Louisiana, doubts that a plant virus could recognise animal cells.
IN BRIEF Nicotine may raise Alzheimer’s risk SMOKING could predispose people to dementia, not protect them as had been suggested. Rats with brain plaques develop further symptoms of Alzheimer’s when given nicotine. In Alzheimer’s disease, the brain becomes riddled with amyloid plaques and tangles of tau proteins. Low doses of nicotine reduce the number of plaques in rats, yet little was known about the effect on the protein tangles. To find out, Yan-Jiang Wang’s team at Third Military Medical University in Chongqing, China, injected plaques into the brains of healthy rats and gave some a smoker’s daily dose of nicotine for two weeks, others nothing. All the rats showed early signs of tau tangles and had difficulty navigating a maze, but the rats on nicotine were worse off (European Journal of Pharmacology, DOI: 10.1016/j.ejphar.2010.03.029).
People pick up pepper virus
New-found hominid cousin is a brain teaser NOT only have we found a long-lost cousin, but it now appears that the skull of newly unveiled Australopithecus sediba contains a print of its brain. The skull of the young male australopithecine, unearthed in South Africa, is so well preserved that early analysis of X-ray tomographic images taken at the European Synchrotron Research Facility (ESRF) in Grenoble, France, reveals that the brain may have left its imprint on sediment filling the skull. Though tantalising, Paul Tafforeau, a palaeontologist at the ESRF, is cautious about what new insights the imprint may yield. Brain or no brain, A. sediba is significant because its anatomy is the most similar of any australopithecine yet found to the true humans that evolved into us. Two partial skeletons, one of a male child aged 9 to 13 years and the other of an adult female, were dug up in the Cradle of
14 | NewScientist | 17 April 2010
Humankind world heritage site near Johannesburg by Lee Berger of the University of the Witwatersrand in Johannesburg and colleagues. They are between 1.95 and 1.78 million years old (Science, vol 328, p 195). Though its physical features are the most human-like of any australopithecine yet discovered, A. sediba is hundreds of thousands of years younger than the oldest fossils assigned to the genus Homo, meaning it is unlikely to be our direct ancestor. The juvenile is the most complete australopithecine skeleton yet found from the period: it includes much of the skull and large parts of an arm, leg and pelvis. Both hominids were about 1.2 metres tall, with ape-sized brains. “This is the most human-like australopithecine yet discovered,” says Chris Stringer of the Natural History Museum in London, who was not involved in the study.
COULD a plant virus have found a way to infect humans? It has always been assumed that plant viruses cannot infect animals, and vice versa. But now Didier Raoult at the University of the Mediterranean in Marseille, France, and his team have found RNA from the pepper mild mottle virus in the faeces of 7 per cent of the 304 adults they tested. Those with the virus were more likely to report fever, abdominal pain and itching than those without it (PLoS One, DOI: 10.1371/journal. pone.0010041). The team is now looking for direct proof that the virus causes these symptoms. But Robert Garry at Tulane University in New Orleans, Louisiana, doubts that a plant virus could recognise animal cells.