- Email: [email protected]
New cache of fresh neurons found in human brains
Borbala Ferenczy
in Brief Warmer world may slow the Atlantic
Paws for thought: dogs respond to calls just like us LISTEN up Fido! The brains of humans and dogs respond in the same way to vocal sounds like laughter and barking. The finding suggests that our voice processing areas are inherited from a common ancestor. Attila Andics of the MTA-ELTE Comparative Ethology Research Group in Budapest, Hungary, and his colleagues trained 11 dogs to lie in an fMRI scanner. As the dogs listened to nearly 200 human and dog noises, the team recorded brain activity. They also performed the same experiment on 22 humans. Animals are usually sedated for scans. But recently,
better training has meant some dogs will lie still long enough to be scanned while awake. Andics is the first to compare humans and dogs in the same experiment. Human and dog brains lit up in similar areas, centred on the temporal lobes, in response to the sounds (Current Biology, doi.org/rnb). Dogs responded more to dog sounds, and humans more to human sounds. Andics says the results hint at a single evolutionary origin for the voice processing area of human and dog brains, dating back to at least 100 million years ago – the last time humans and dogs shared an ancestor. But Clive Wynne of Arizona State University in Tempe offers an alternative explanation. “The brain is a highly plastic organ, and the dogs’ responses could just be the result of a lifetime listening to human voices,” he says.
Bomb tests reveal youthful brain cells YOUNG brain cells have been seen in a novel location in the brain. The finding raises hopes that the cells could be utilised to help people recover after a stroke, or to treat degenerative brain diseases. Last year, Jonas Frisén at the Karolinska Institute in Stockholm, Sweden, and his colleagues showed that brain cells younger than their owner turn up in the hippocampus, 18 | NewScientist | 1 March 2014
a brain region crucial to memory. They have now found that such brain cells also move to a golf-ball-sized structure called the striatum. This region is involved in a range of functions, including learning and memory. These particular traits, shared as they are with the hippocampus, lead Frisén to speculate that brain cells appearing here may also be involved in learning.
“New neurons may convey some sort of plasticity,” he says, which might help people learn and adapt. To reveal the younger cells, the team exploited the fact that atmospheric levels of radioactive carbon-14 have been falling since nuke tests raised them up during the cold war. New cells incorporate this carbon-14, and its levels in the various cells of 30 donated brains revealed neurons that had been created during the lifetimes of the donors (Cell, doi.org/rm8).
A WARMING world could slow the circulation of the Atlantic Ocean, triggering African droughts and faster sea level rise in Europe. Eirik Vinje Galaasen at the University of Bergen, Norway, and his colleagues looked at deep-sea sediments from a site off south Greenland, which record shortlived climate shifts. During a warm period 130,000 to 115,000 years ago, the ratio of carbon isotopes in fossilised microbes shifted suddenly several times. That suggests abrupt changes in the circulation of deep water in the Atlantic (Science, doi.org/rnj). If it happens again, European seas will rise faster. North Africa may suffer severe droughts, if the slow currents shift air circulation. But it is unclear if such changes will happen soon, says Carl Wunsch at the Massachusetts Institute of Technology. We still know little about how ocean circulation varies over millennia, he says.
Alphabet to decode medieval text LOST language, or gibberish? Some of the symbols in the 15th-century Voynich manuscript have been matched to sounds in an effort to decode it. Earlier studies of the 240-page tome looked for patterns typical of a language. Stephen Bax at the University of Bedfordshire in Luton, UK, instead focused on single letters. He selected words that seem to label drawings of recognisable objects and compared them with the names of the items in various languages. Knowing how these words are pronounced gave possible sounds for the different symbols making up the words. He then applied those to other labels, giving him 14 letters of a possible alphabet. The analysis is at bit.ly/1k37qvb.
in Brief Warmer world may slow the Atlantic
Paws for thought: dogs respond to calls just like us LISTEN up Fido! The brains of humans and dogs respond in the same way to vocal sounds like laughter and barking. The finding suggests that our voice processing areas are inherited from a common ancestor. Attila Andics of the MTA-ELTE Comparative Ethology Research Group in Budapest, Hungary, and his colleagues trained 11 dogs to lie in an fMRI scanner. As the dogs listened to nearly 200 human and dog noises, the team recorded brain activity. They also performed the same experiment on 22 humans. Animals are usually sedated for scans. But recently,
better training has meant some dogs will lie still long enough to be scanned while awake. Andics is the first to compare humans and dogs in the same experiment. Human and dog brains lit up in similar areas, centred on the temporal lobes, in response to the sounds (Current Biology, doi.org/rnb). Dogs responded more to dog sounds, and humans more to human sounds. Andics says the results hint at a single evolutionary origin for the voice processing area of human and dog brains, dating back to at least 100 million years ago – the last time humans and dogs shared an ancestor. But Clive Wynne of Arizona State University in Tempe offers an alternative explanation. “The brain is a highly plastic organ, and the dogs’ responses could just be the result of a lifetime listening to human voices,” he says.
Bomb tests reveal youthful brain cells YOUNG brain cells have been seen in a novel location in the brain. The finding raises hopes that the cells could be utilised to help people recover after a stroke, or to treat degenerative brain diseases. Last year, Jonas Frisén at the Karolinska Institute in Stockholm, Sweden, and his colleagues showed that brain cells younger than their owner turn up in the hippocampus, 18 | NewScientist | 1 March 2014
a brain region crucial to memory. They have now found that such brain cells also move to a golf-ball-sized structure called the striatum. This region is involved in a range of functions, including learning and memory. These particular traits, shared as they are with the hippocampus, lead Frisén to speculate that brain cells appearing here may also be involved in learning.
“New neurons may convey some sort of plasticity,” he says, which might help people learn and adapt. To reveal the younger cells, the team exploited the fact that atmospheric levels of radioactive carbon-14 have been falling since nuke tests raised them up during the cold war. New cells incorporate this carbon-14, and its levels in the various cells of 30 donated brains revealed neurons that had been created during the lifetimes of the donors (Cell, doi.org/rm8).
A WARMING world could slow the circulation of the Atlantic Ocean, triggering African droughts and faster sea level rise in Europe. Eirik Vinje Galaasen at the University of Bergen, Norway, and his colleagues looked at deep-sea sediments from a site off south Greenland, which record shortlived climate shifts. During a warm period 130,000 to 115,000 years ago, the ratio of carbon isotopes in fossilised microbes shifted suddenly several times. That suggests abrupt changes in the circulation of deep water in the Atlantic (Science, doi.org/rnj). If it happens again, European seas will rise faster. North Africa may suffer severe droughts, if the slow currents shift air circulation. But it is unclear if such changes will happen soon, says Carl Wunsch at the Massachusetts Institute of Technology. We still know little about how ocean circulation varies over millennia, he says.
Alphabet to decode medieval text LOST language, or gibberish? Some of the symbols in the 15th-century Voynich manuscript have been matched to sounds in an effort to decode it. Earlier studies of the 240-page tome looked for patterns typical of a language. Stephen Bax at the University of Bedfordshire in Luton, UK, instead focused on single letters. He selected words that seem to label drawings of recognisable objects and compared them with the names of the items in various languages. Knowing how these words are pronounced gave possible sounds for the different symbols making up the words. He then applied those to other labels, giving him 14 letters of a possible alphabet. The analysis is at bit.ly/1k37qvb.