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Topic: Social status influences brain structure (Read 578 times) |
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rhinoceros
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Social status influences brain structure
« on: 2004-08-05 21:35:28 » |
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Here's an interesting experiment of scribbling on the blank(?) slate. It seems that leading the pack gets you a new brain for the job, rather than the other way around. (Also posted in the "Science and Technology" section of the BBS)
Social status influences brain structure Helen Pilcher Nature, 05 August 2004
Assertive rats sprout extra nerve cells.
http://www.nature.com/news/2004/040802/full/040802-18.html
Assertiveness really is all in the mind. Dominant rats have more new nerve cells in a key brain region than their subordinates, a study reveals.
The finding hints that social hierarchies can influence brain structure, and raises questions over the use of standard animal behaviour tests in laboratory research.
Yevgenia Kozorovitskiy and Elizabeth Gould from Princeton University, New Jersey, studied the brains of around 40 rats that had been left to form social hierarchies in a semi-natural setting. Their results are published in The Journal of Neuroscience1.
In each experiment, four males and two females were placed inside a large box comprising an underground tangle of burrows and chambers and a feeding area above. Within three days, the males had established their preferred pecking order: an aggressive leader who attracted the females and three defensive subordinates.
Two weeks later, the high-status animals were found to have around 30% more neurons in their hippocampus, a brain region implicated in learning and memory, than they had before.
Neurons in this area are constantly recycled, says Kozorovitskiy. Around 9,000 new nerve cells are born every day, but most die within a week. In the dominant animals, however, the new cells survive for longer.
Although their exact function is unknown, it is thought that these extra neurons could help the animals adapt to their position of power. Whether the same phenomenon occurs in humans is not known.
Other factors, such as exercise and environmental enrichment, trigger the production of new nerve cells in the same area. "These cells are amazingly responsive to environmental conditions," says neuroscientist Tracey Shors from Rutgers, the State University of New Jersey.
Social climbing
The strain of rat that Kozorovitskiy and Gould used is normally passive, and does not form dominance hierarchies when housed in standard laboratory cages without tunnels.
Although the researchers had hoped that placing the animals in burrows would encourage them to form hierarchies, they were surprised to see the animals' social structure change so quickly, with a wealth of individual differences in behaviour appearing within days.
Kozorovitskiy suggests that studying rats in burrows is likely to be much more relevant to understanding human behaviour than tests carried out in standard cages.
"Standard laboratory housing may suppress individual variability," agrees neuroscientist Larry Young from Emory University in Atlanta, Georgia. "So the behaviour you see may be different from that you would observe in nature."
Most laboratory protocols suppress individual differences between test animals. But many researchers are now moving towards tests that enhance individual behaviour. These models should be more relevant to human disease, says Young.
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ElvenSage
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Think for yourself, question authority.
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Re:Social status influences brain structure
« Reply #1 on: 2004-08-06 08:49:40 » |
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This was an expecially interesting article for me. I have noticed simular things within myself. I used to be the 'leader' and center of my ring of friends for a couple years. This was the case up until I was unable to uphold the position due to working schedules. Since then my memory has been worse, and such. Perhaps the brain seems to have a better memory capacity when you are happier. It's scientificly known that being happy benefits you in all sorts of ways, so I do not think that believing the brains performance is improved under the cercumstance of being happy, is too far-fetched.
Great post rhino!
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Safe from the pain and truth and choice and other poison devils See.. they don't give a fuck about you, like i do. Just stay with me, safe and ignorant, Go back to sleep Go Back to sleep
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Drakeo Vortex
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Re:Social status influences brain structure
« Reply #2 on: 2004-08-06 11:43:08 » |
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Interesting this phenomenom traces all the way back to early mammals. The studies on apes have been quite thorough. I witness the human extremes of heirarchial manipulation. The difference is so substanial between sexes it must be rooted very early in the primitive brain. Although this type of behavior would arise indepently in different species quite easily. Males not fighting larger males than themselves would reproduce more. Even in asexual species that have some type of identifiable community you could say that thier is a hierarchy if they more often than not refuse to fight larger opponents compared to smaller ones. The genetic 'theory' here is almost flawless. However neurologically is good to see some evidence which gives hope in the future for more sophisticated hierarchial explanations through the apes to the humans.
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rhinoceros
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Re:Social status influences brain structure
« Reply #3 on: 2004-08-09 21:12:15 » |
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Yesterday I heard once more the all too familiar "He is not who he used to be" for a friend who was assigned a position of responsibilty a couple of years ago. I wonder if anyone will check the brains of humans any time soon for verification of the folk wisdom about authority.
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