Nov 6, 2019 11:47 PM
(This post was last modified: Nov 7, 2019 05:16 PM by C C.)
PhD candidate stumbled upon evidence disproving a 25-year-old belief about the brain
https://sciencenorway.no/alzheimers-brai...in/1589016
EXCERPT: . . . A recognized model states that there are two parallel streams of information: One stream includes visual sensory impressions that travel to the sense of place, and the second stream is of other impressions that go to the lateral entorhinal cortex – the area that integrates our sense of time with the content of our memories.
Thanh Pierre Doan dyes rat brain cells to get a picture of where the information pathways are. But the data coming out of the experiments aren’t matching the model. Instead of finding two parallel streams, Doan's results show that almost all the information whizzes directly into the lateral entorhinal cortex, the time-sense part of the brain. It appears that the lateral entorhinal cortex is an information supercentre for everything coming in from the entire sensory system and the brain. It’s like the brain version of all roads leading to Rome.
[...] It doesn’t take long for Doan’s data to turn his supervisor’s initial scepticism into enthusiasm. An old model may fall, but that’s what happens to scientific models from time to time. And the possibilities that open up are even more exciting. Doan and Witter embark on the intense work of finding out if it’s true that the model is really wrong – and that the brain has one supercentre for information instead of two parallel streams of information. Thanks to Witter, they have exactly what they need to get to the bottom of the matter: a whole load of old samples.
[...] The signs were there the whole time. The researchers behind the old studies even noted that there were some weird features of the results that didn’t quite fit. Why hadn’t anyone understood the connection before? Witter believes there may be several reasons for that. “All scientists do experiments based on a certain idea or model. This guides the study design and how we read the results,” he says. And the rapid technological developments have clearly given today's researchers much more precise and sensitive research methods, which enable previously unknown details to emerge. These details can give us completely new insights into how the brain works.
[...] Doan's findings and several other studies suggest that the lateral entorhinal cortex is quite special. This layer of cells is literally connected to everything. As with cells elsewhere in the brain, these cells have lots of web-like strands that extend outward. These threads have tens of thousands of connections to other neurons and can receive signals from them.
But there the similarity ends. In most places, cells are selectively attached to cells from two or three other regions in the brain. However, the cells in the lateral entorhinal cortex have links to many more places, including the brain region that creates our sense of place. "These cells take in an absolutely insane amount of different information," says Doan.
The lateral entorhinal cortex appears to be the brain's information centre. It is probably the place that takes all kinds of information and puts it together into something that makes sense. Then it sends it on to the hippocampus. "This is the first indication we have that the lateral entorhinal cortex plays such a critical role in the system for making complex memories," says Witter. (MORE details)
Earliest ape adapted to walk upright found in Germany
https://www.cbc.ca/news/technology/biped...-1.4637336
INTRO: The remains of an ancient ape found in a Bavarian clay pit suggest that humans' ancestors began standing upright millions of years earlier than previously thought, scientists said Wednesday. The remains of an ancient ape found in a Bavarian clay pit suggest that humans' ancestors began standing upright millions of years earlier than previously thought, scientists said Wednesday.
An international team of researchers says the fossilized partial skeleton of a male ape that lived almost 12 million years ago in the humid forests of what is now southern Germany bears a striking resemblance to modern human bones. In a paper published by the journal Nature, they concluded that the previously unknown species — named Danuvius guggenmosi — could walk on two legs but also climb like an ape.
The findings "raise fundamental questions about our previous understanding of the evolution of the great apes and humans," said Madelaine Boehme, of the University of Tübingen, Germany, who led the research. The question of when apes evolved bipedal motion has fascinated scientists since Charles Darwin first argued that they were the ancestors of humans. Previous fossil records of apes with an upright gait — found in Crete and Kenya — dated only as far back as six million years ago. (MORE)
https://sciencenorway.no/alzheimers-brai...in/1589016
EXCERPT: . . . A recognized model states that there are two parallel streams of information: One stream includes visual sensory impressions that travel to the sense of place, and the second stream is of other impressions that go to the lateral entorhinal cortex – the area that integrates our sense of time with the content of our memories.
Thanh Pierre Doan dyes rat brain cells to get a picture of where the information pathways are. But the data coming out of the experiments aren’t matching the model. Instead of finding two parallel streams, Doan's results show that almost all the information whizzes directly into the lateral entorhinal cortex, the time-sense part of the brain. It appears that the lateral entorhinal cortex is an information supercentre for everything coming in from the entire sensory system and the brain. It’s like the brain version of all roads leading to Rome.
[...] It doesn’t take long for Doan’s data to turn his supervisor’s initial scepticism into enthusiasm. An old model may fall, but that’s what happens to scientific models from time to time. And the possibilities that open up are even more exciting. Doan and Witter embark on the intense work of finding out if it’s true that the model is really wrong – and that the brain has one supercentre for information instead of two parallel streams of information. Thanks to Witter, they have exactly what they need to get to the bottom of the matter: a whole load of old samples.
[...] The signs were there the whole time. The researchers behind the old studies even noted that there were some weird features of the results that didn’t quite fit. Why hadn’t anyone understood the connection before? Witter believes there may be several reasons for that. “All scientists do experiments based on a certain idea or model. This guides the study design and how we read the results,” he says. And the rapid technological developments have clearly given today's researchers much more precise and sensitive research methods, which enable previously unknown details to emerge. These details can give us completely new insights into how the brain works.
[...] Doan's findings and several other studies suggest that the lateral entorhinal cortex is quite special. This layer of cells is literally connected to everything. As with cells elsewhere in the brain, these cells have lots of web-like strands that extend outward. These threads have tens of thousands of connections to other neurons and can receive signals from them.
But there the similarity ends. In most places, cells are selectively attached to cells from two or three other regions in the brain. However, the cells in the lateral entorhinal cortex have links to many more places, including the brain region that creates our sense of place. "These cells take in an absolutely insane amount of different information," says Doan.
The lateral entorhinal cortex appears to be the brain's information centre. It is probably the place that takes all kinds of information and puts it together into something that makes sense. Then it sends it on to the hippocampus. "This is the first indication we have that the lateral entorhinal cortex plays such a critical role in the system for making complex memories," says Witter. (MORE details)
Earliest ape adapted to walk upright found in Germany
https://www.cbc.ca/news/technology/biped...-1.4637336
INTRO: The remains of an ancient ape found in a Bavarian clay pit suggest that humans' ancestors began standing upright millions of years earlier than previously thought, scientists said Wednesday. The remains of an ancient ape found in a Bavarian clay pit suggest that humans' ancestors began standing upright millions of years earlier than previously thought, scientists said Wednesday.
An international team of researchers says the fossilized partial skeleton of a male ape that lived almost 12 million years ago in the humid forests of what is now southern Germany bears a striking resemblance to modern human bones. In a paper published by the journal Nature, they concluded that the previously unknown species — named Danuvius guggenmosi — could walk on two legs but also climb like an ape.
The findings "raise fundamental questions about our previous understanding of the evolution of the great apes and humans," said Madelaine Boehme, of the University of Tübingen, Germany, who led the research. The question of when apes evolved bipedal motion has fascinated scientists since Charles Darwin first argued that they were the ancestors of humans. Previous fossil records of apes with an upright gait — found in Crete and Kenya — dated only as far back as six million years ago. (MORE)