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False memories generated in lab mice
GUIDO HARARI/Contrasto/eyevine
IN BRIEF Dolphin social networks are open
Opera and classical music’s boost for heart-swap mice CLASSICAL music is good for the soul and maybe the heart too. Mice with heart transplants survived twice as long if they listened to classical music rather than ambient music or monotones after their operation. Masateru Uchiyama of Juntendo University Hospital in Tokyo, Japan, gave mice transplants from an unrelated donor which were therefore expected to be rejected. For a week following the operation, the mice continuously listened to Verdi’s opera La Traviata, a selection of Mozart concertos, music by Enya, or a range of single monotones. Mice exposed to opera fared best – they survived an
average of 26 days. Mice who heard Mozart lasted 20 days and the Enya mice 11 days. The monotone group survived only seven days, as did deaf mice exposed to La Traviata. Classical music appeared to slow organ rejection by calming the immune system. Blood from these mice had lower concentrations of interleukin-2 and gamma interferon – which promote inflammation – and higher levels of substances that dampen inflammation, such as interleukin-4 (Journal of Cardiothoracic Surgery, in press). “We don’t know the exact mechanisms but the harmony of Verdi and Mozart may be important,” says Uchiyama. The team would like to see if the phenomenon could help the success of transplants in people. A previous study found that music therapy can influence pain and nausea in people following a bone marrow transplant.
False memories induced in mice COULD memories be controlled using drugs? Researchers have shown that it is possible to manipulate the neurons used to store a specific memory to create false memories – in mice at least. Mark Mayford of the Scripps Research Institute in San Diego, California, and colleagues genetically engineered mice so that neurons that fired while a memory was being formed would 16 | NewScientist | 31 March 2012
fire again when the brain was injected with a drug. They put each mouse into a box associated with a colour and smell, which encouraged a group of neurons to fire and form a memory. Next they put each rodent into a box with a new colour and smell. They injected the drug, making the mouse remember the first box, and then gave it a shock. Normally the shock would
encourage the mouse to fear the second box. But because it was in the second box but remembering the first, it developed a fear of a mixture of both boxes – an imaginary environment. The only time the mouse would panic was when it was in the second box and the drug was injected (Science, DOI: 10.1126/science.1214985). Mayford says this “hybrid” false memory suggests two sets of neurons encode each memory and do not interfere with each other.
LONG-distance swimming may have opened up a world of complexity for dolphins. Male bottlenose dolphins in Shark Bay, Western Australia, cooperate in groups of two or three. These groups also link with others to form gangs of up to 14 males, and sometimes two or more large gangs coalesce. Such complex alliances usually form to control either territory or sexual partners. Richard Connor of the University of Massachusetts Dartmouth tracked 120 males in the bay and found no evidence that dolphins form the groups for either reason, suggesting their society is unusually open (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2012.0264). Humans and elephants also form complex groups. As with dolphins, they use little energy to travel vast distances, hinting that this contributed to the evolution of complex social networks.
Worm wears its ovaries outside TALK about letting it all hang out. A worm living off the California coast is the first animal known to sport external ovaries. Karen Osborn of the Smithsonian Institution in Washington DC spotted the new species of acorn worm (Allapasus aurantiacus) via a remotely operated vehicle. She had it brought to the surface and found it had two flaps of skin running along much of its body. Its ovaries were attached to the inner surfaces of these flaps. “Usually you want to protect these things,” Osborn says. But just one layer of cells protects the eggs of A. aurantiacus. That might make it easier for sperm to reach them (Journal of Morphology, DOI: 10.1002/jmor.20013).
IN BRIEF Dolphin social networks are open
Opera and classical music’s boost for heart-swap mice CLASSICAL music is good for the soul and maybe the heart too. Mice with heart transplants survived twice as long if they listened to classical music rather than ambient music or monotones after their operation. Masateru Uchiyama of Juntendo University Hospital in Tokyo, Japan, gave mice transplants from an unrelated donor which were therefore expected to be rejected. For a week following the operation, the mice continuously listened to Verdi’s opera La Traviata, a selection of Mozart concertos, music by Enya, or a range of single monotones. Mice exposed to opera fared best – they survived an
average of 26 days. Mice who heard Mozart lasted 20 days and the Enya mice 11 days. The monotone group survived only seven days, as did deaf mice exposed to La Traviata. Classical music appeared to slow organ rejection by calming the immune system. Blood from these mice had lower concentrations of interleukin-2 and gamma interferon – which promote inflammation – and higher levels of substances that dampen inflammation, such as interleukin-4 (Journal of Cardiothoracic Surgery, in press). “We don’t know the exact mechanisms but the harmony of Verdi and Mozart may be important,” says Uchiyama. The team would like to see if the phenomenon could help the success of transplants in people. A previous study found that music therapy can influence pain and nausea in people following a bone marrow transplant.
False memories induced in mice COULD memories be controlled using drugs? Researchers have shown that it is possible to manipulate the neurons used to store a specific memory to create false memories – in mice at least. Mark Mayford of the Scripps Research Institute in San Diego, California, and colleagues genetically engineered mice so that neurons that fired while a memory was being formed would 16 | NewScientist | 31 March 2012
fire again when the brain was injected with a drug. They put each mouse into a box associated with a colour and smell, which encouraged a group of neurons to fire and form a memory. Next they put each rodent into a box with a new colour and smell. They injected the drug, making the mouse remember the first box, and then gave it a shock. Normally the shock would
encourage the mouse to fear the second box. But because it was in the second box but remembering the first, it developed a fear of a mixture of both boxes – an imaginary environment. The only time the mouse would panic was when it was in the second box and the drug was injected (Science, DOI: 10.1126/science.1214985). Mayford says this “hybrid” false memory suggests two sets of neurons encode each memory and do not interfere with each other.
LONG-distance swimming may have opened up a world of complexity for dolphins. Male bottlenose dolphins in Shark Bay, Western Australia, cooperate in groups of two or three. These groups also link with others to form gangs of up to 14 males, and sometimes two or more large gangs coalesce. Such complex alliances usually form to control either territory or sexual partners. Richard Connor of the University of Massachusetts Dartmouth tracked 120 males in the bay and found no evidence that dolphins form the groups for either reason, suggesting their society is unusually open (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2012.0264). Humans and elephants also form complex groups. As with dolphins, they use little energy to travel vast distances, hinting that this contributed to the evolution of complex social networks.
Worm wears its ovaries outside TALK about letting it all hang out. A worm living off the California coast is the first animal known to sport external ovaries. Karen Osborn of the Smithsonian Institution in Washington DC spotted the new species of acorn worm (Allapasus aurantiacus) via a remotely operated vehicle. She had it brought to the surface and found it had two flaps of skin running along much of its body. Its ovaries were attached to the inner surfaces of these flaps. “Usually you want to protect these things,” Osborn says. But just one layer of cells protects the eggs of A. aurantiacus. That might make it easier for sperm to reach them (Journal of Morphology, DOI: 10.1002/jmor.20013).