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Junk food “inflammation” cues trigger diabetes
IN BRIEF
GARION HUTCHINGS/spl
PSYCHEDELIC drug users through the ages have described their experiences as mind-expanding. But psilocybin – the active ingredient in magic mushrooms – actually decreases blood flow and connectivity in areas of the brain that are associated with perception and cognition. Robin Carhart-Harris at Imperial College London and colleagues recruited 30 volunteers who agreed to be injected with psilocybin and have their brain scanned using fMRI. Half of the volunteers had their blood flow measured during the resulting trip; the rest underwent a scan that measured connectivity between different brain regions. Less blood flow was seen in the thalamus, the posterior cingulate and the medial prefrontal cortex. Decreases in connectivity between brain regions were also observed. “We thought profound experience equalled more activity, but this formula is clearly too simplistic,” says Carhart-Harris. “We didn’t see an increase in any regions.” The brain regions where blood flow fell tend to be overactive in people who suffer from depression, making psilocybin a potential treatment for the condition. Carhart-Harris presented his work at the Breaking Convention conference at the University of Kent in Canterbury, UK, last week.
20 | NewScientist | 16 April 2011
Life had left the oceans a billion years ago POOLS of water on land were a lot livelier 1 billion years ago than previously thought. It is generally assumed that life began in the ocean around 3.8 billion years ago, then moved onto land. Until now, there had been little evidence to suggest this landward migration happened before half a billion years ago. The discovery of eukaryote cells in 1-billion-year-old lake sediment looks set to change that. Paul Strother at Boston College in Weston, Massachusetts, and colleagues discovered cyst-like
bubbles made of organic matter in 1 to 1.2-billion-year-old lake deposits. The bubbles were packed full of fossilised cells, and found in a number of locations across the north-west of Scotland, UK. Strother says the cells, which appear to be going through vegetative reproduction, show a level of structural complexity “beyond that seen in bacteria” but characteristic of eukaryotes – one of the three domains of life. This suggests the primitive relatives of all animals, plants and fungi
had left the oceans and moved into terrestrial waters twice as long ago as thought (Nature, DOI: 10.1038/nature09943). Palaeontologists contacted by New Scientist for comment, including Andrew Knoll at Harvard University, agreed with Strother’s conclusions. Eukaryotes may not have been the sole colonisers of land at the time. There is also evidence that cyanobacteria – some of the earliest known forms of life – evolved first in fresh water, before moving to the ocean. IAN BEDFORD/JOHN INNES CENTRE/spl
Magic mushrooms close the mind
For new stories every day, visit www.NewScientist.com/news
How junk food triggers diabetes FATTY foods might trigger type 2 diabetes by mimicking the inflammation normally caused by bacteria, viruses and harmful substances such as asbestos. To investigate the effects of fatty food on the immune system, researchers led by Jenny Ting at the University of North Carolina, Chapel Hill, exposed mouse immune cells called macrophages to palmitate, an unsaturated fat found in many processed foods. They found that the palmitate interacted with bundles of proteins inside the macrophages called inflammasomes, releasing a substance called interleukin-1 beta that is known to “blind” liver, fat and muscle tissue to insulin. In people, this blindness to insulin ultimately leads to type 2 diabetes. The team went on to show that mice genetically engineered to have inactive inflammasomes didn’t develop diabetes-like symptoms, even when fed a highfat diet (Nature Immunology, DOI: 10.1038/ni.2022). “These results support the idea that inflammation plays a role in chronic disease,” says Ting. “The simple message is to avoid fatty foods as much as possible.”
Bug boosts whitefly sex life The whitefly is a pest with a helpful lodger. It carries a bug that messes with its sex life – but which, in doing so, could help it spread further. Whitefly devastated sweet-potato crops in the south-western US in the 1980s and 90s, and still costs millions of dollars in crop damage worldwide. Strikingly, the proportion of whitefly infected with the bacterium Rickettsia bellii in Arizona, New Mexico and California soared from 1 per cent in 2000 to 97 per cent in 2006. To explain the swift proliferation, Anna Himler at the University of
Arizona in Tucson took the pest to the lab. When she mated an uninfected male with an infected female, she found that almost all offspring carried Rickettsia, suggesting the bacterium is passed from mother to young. Usefully for whitefly and microbe alike, infected females laid more eggs than others, and more of these survived to adulthood (Science, DOI: 10.1126/ science.1199410). What’s more, infected females produced more daughters than sons. It seems Rickettsia controls their sex life, to the benefit of both species.
GARION HUTCHINGS/spl
PSYCHEDELIC drug users through the ages have described their experiences as mind-expanding. But psilocybin – the active ingredient in magic mushrooms – actually decreases blood flow and connectivity in areas of the brain that are associated with perception and cognition. Robin Carhart-Harris at Imperial College London and colleagues recruited 30 volunteers who agreed to be injected with psilocybin and have their brain scanned using fMRI. Half of the volunteers had their blood flow measured during the resulting trip; the rest underwent a scan that measured connectivity between different brain regions. Less blood flow was seen in the thalamus, the posterior cingulate and the medial prefrontal cortex. Decreases in connectivity between brain regions were also observed. “We thought profound experience equalled more activity, but this formula is clearly too simplistic,” says Carhart-Harris. “We didn’t see an increase in any regions.” The brain regions where blood flow fell tend to be overactive in people who suffer from depression, making psilocybin a potential treatment for the condition. Carhart-Harris presented his work at the Breaking Convention conference at the University of Kent in Canterbury, UK, last week.
20 | NewScientist | 16 April 2011
Life had left the oceans a billion years ago POOLS of water on land were a lot livelier 1 billion years ago than previously thought. It is generally assumed that life began in the ocean around 3.8 billion years ago, then moved onto land. Until now, there had been little evidence to suggest this landward migration happened before half a billion years ago. The discovery of eukaryote cells in 1-billion-year-old lake sediment looks set to change that. Paul Strother at Boston College in Weston, Massachusetts, and colleagues discovered cyst-like
bubbles made of organic matter in 1 to 1.2-billion-year-old lake deposits. The bubbles were packed full of fossilised cells, and found in a number of locations across the north-west of Scotland, UK. Strother says the cells, which appear to be going through vegetative reproduction, show a level of structural complexity “beyond that seen in bacteria” but characteristic of eukaryotes – one of the three domains of life. This suggests the primitive relatives of all animals, plants and fungi
had left the oceans and moved into terrestrial waters twice as long ago as thought (Nature, DOI: 10.1038/nature09943). Palaeontologists contacted by New Scientist for comment, including Andrew Knoll at Harvard University, agreed with Strother’s conclusions. Eukaryotes may not have been the sole colonisers of land at the time. There is also evidence that cyanobacteria – some of the earliest known forms of life – evolved first in fresh water, before moving to the ocean. IAN BEDFORD/JOHN INNES CENTRE/spl
Magic mushrooms close the mind
For new stories every day, visit www.NewScientist.com/news
How junk food triggers diabetes FATTY foods might trigger type 2 diabetes by mimicking the inflammation normally caused by bacteria, viruses and harmful substances such as asbestos. To investigate the effects of fatty food on the immune system, researchers led by Jenny Ting at the University of North Carolina, Chapel Hill, exposed mouse immune cells called macrophages to palmitate, an unsaturated fat found in many processed foods. They found that the palmitate interacted with bundles of proteins inside the macrophages called inflammasomes, releasing a substance called interleukin-1 beta that is known to “blind” liver, fat and muscle tissue to insulin. In people, this blindness to insulin ultimately leads to type 2 diabetes. The team went on to show that mice genetically engineered to have inactive inflammasomes didn’t develop diabetes-like symptoms, even when fed a highfat diet (Nature Immunology, DOI: 10.1038/ni.2022). “These results support the idea that inflammation plays a role in chronic disease,” says Ting. “The simple message is to avoid fatty foods as much as possible.”
Bug boosts whitefly sex life The whitefly is a pest with a helpful lodger. It carries a bug that messes with its sex life – but which, in doing so, could help it spread further. Whitefly devastated sweet-potato crops in the south-western US in the 1980s and 90s, and still costs millions of dollars in crop damage worldwide. Strikingly, the proportion of whitefly infected with the bacterium Rickettsia bellii in Arizona, New Mexico and California soared from 1 per cent in 2000 to 97 per cent in 2006. To explain the swift proliferation, Anna Himler at the University of
Arizona in Tucson took the pest to the lab. When she mated an uninfected male with an infected female, she found that almost all offspring carried Rickettsia, suggesting the bacterium is passed from mother to young. Usefully for whitefly and microbe alike, infected females laid more eggs than others, and more of these survived to adulthood (Science, DOI: 10.1126/ science.1199410). What’s more, infected females produced more daughters than sons. It seems Rickettsia controls their sex life, to the benefit of both species.