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All things brain...

Started by Claireliontamer, July 12, 2017, 08:18:49 PM

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Icarus


Icarus


Ecurb Noselrub

Quote from: Icarus on September 12, 2019, 12:38:13 AM
This bit examines dreams and what is going on in the brain while dreaming.

https://elemental.medium.com/what-happens-in-the-brain-when-youre-dreaming-7c0687c38d3

Very interesting.  I've often thought that in dreams the mind is taking the experiences of the day and weaving them into some story that tries to make sense of things, even in a bizarre fashion. The brain is so complex.

Recusant

I suppose the idea that mammals use the same general location in the brain to process our perception of numbers would not be particularly controversial.  ;)

"Dogs process numerical quantities in similar brain region as humans" | ScienceDaily

QuoteDogs spontaneously process basic numerical quantities, using a distinct part of their brains that corresponds closely to number-responsive neural regions in humans, finds a study at Emory University.

Biology Letters published the results, which suggest that a common neural mechanism has been deeply conserved across mammalian evolution.

"Our work not only shows that dogs use a similar part of their brain to process numbers of objects as humans do -- it shows that they don't need to be trained to do it," says Gregory Berns, Emory professor of psychology and senior author of the study.

"Understanding neural mechanisms -- both in humans and across species -- gives us insights into both how our brains evolved over time and how they function now," says co-author Stella Lourenco, an associate professor of psychology at Emory.

Such insights, Lourenco adds, may one day lead to practical applications such as treating brain abnormalities and improving artificial intelligence systems.

Lauren Aulet, a PhD candidate in Lourenco's lab, is first author of the study.

The study used functional magnetic resonance imaging (fMRI) to scan dogs' brains as they viewed varying numbers of dots flashed on a screen. The results showed that the dogs' parietotemporal cortex responded to differences in the number of the dots. The researchers held the total area of the dots constant, demonstrating that it was the number of the dots, not the size, that generated the response.

[Continues . . .]

"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


xSilverPhinx

Quote from: Recusant on December 24, 2019, 10:24:15 PM
I suppose the idea that mammals use the same general location in the brain to process our perception of numbers would not be particularly controversial.  ;)

"Dogs process numerical quantities in similar brain region as humans" | ScienceDaily

QuoteDogs spontaneously process basic numerical quantities, using a distinct part of their brains that corresponds closely to number-responsive neural regions in humans, finds a study at Emory University.

Biology Letters published the results, which suggest that a common neural mechanism has been deeply conserved across mammalian evolution.

"Our work not only shows that dogs use a similar part of their brain to process numbers of objects as humans do -- it shows that they don't need to be trained to do it," says Gregory Berns, Emory professor of psychology and senior author of the study.

"Understanding neural mechanisms -- both in humans and across species -- gives us insights into both how our brains evolved over time and how they function now," says co-author Stella Lourenco, an associate professor of psychology at Emory.

Such insights, Lourenco adds, may one day lead to practical applications such as treating brain abnormalities and improving artificial intelligence systems.

Lauren Aulet, a PhD candidate in Lourenco's lab, is first author of the study.

The study used functional magnetic resonance imaging (fMRI) to scan dogs' brains as they viewed varying numbers of dots flashed on a screen. The results showed that the dogs' parietotemporal cortex responded to differences in the number of the dots. The researchers held the total area of the dots constant, demonstrating that it was the number of the dots, not the size, that generated the response.

[Continues . . .]

That's interesting!
I am what survives if it's slain - Zack Hemsey


Recusant

They can see the mice's memories! Sort of.

"Engrams emerging as the basic unit of memory" | EurekAlert!

Quote

Memory engram cells labeled green and red in the prefrontal cortex of a mouse.
Image credit: Takashi Kitamura




Though scientist Richard Semon introduced the concept of the "engram" 115 years ago to posit a neural basis for memory, direct evidence for engrams has only begun to accumulate recently as sophisticated technologies and methods have become available. In a new review in Science, Professors Susumu Tonegawa of The Picower Institute for Learning and Memory at MIT and Sheena Josselyn of the Hospital for Sick Children (SickKids) and the University of Toronto describe the rapid progress they and colleagues have been making over the last dozen years in identifying, characterizing and even manipulating engrams, as well as the major outstanding questions of the field.

Experiments in rodents have revealed that engrams exist as multiscale networks of neurons. An experience becomes stored as a potentially retrievable memory in the brain when excited neurons in a brain region such as the hippocampus or amygdala become recruited into a local ensemble. These ensembles combine with others in other regions, such as the cortex, into an "engram complex." Crucial to this process of linking engram cells is the ability of neurons to forge new circuit connections, via processes known as "synaptic plasticity" and "dendritic spine formation." Importantly, experiments show that the memory initially stored across an engram complex can be retrieved by its reactivation but may also persist "silently" even when memories cannot be naturally recalled, for instance in mouse models used to study memory disorders such as early stage Alzheimer's disease.

[Continues . . .]
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


xSilverPhinx

Sheena A. Josselyn and Susumu Tonegawa (Nobel Prize laureate) are two big names in the field. I know plenty of people who do not agree with Tonegawa's conclusions (that he found the engram) in any of his papers. What the engram is and where it can be found is still a matter of debate.

But it's an interesting review! I have sent the link to my labmates. :grin:
I am what survives if it's slain - Zack Hemsey


Recusant

The most highly detailed map (connectome) to date of part of a fruit fly's brain has been constructed. I don't know that the scientists who worked on this project who were not Google employees would appreciate the credit going to Google, but I suppose it makes for a more attention-grabbing headline.



"Google just created the most detailed image of a brain yet" | LiveScience

QuoteScientists have created the most detailed 3D map of an organism brain to date. The mesmerizing threads of blue, yellow, purple and green represent thousands of brain cells and millions of connections found inside the brain of a fruit fly.

This high-resolution map, known as a "connectome," only makes up one-third of a fruit fly's brain but includes a large region involved in learning, navigation, smell and vision. Scientists found over 4,000 different types of neurons, including those involved in the fly's circadian rhythm — or internal clock — that might help researchers learn a bit more about how the insect sleeps, according to the publicly released data.

This map, a collaboration between scientists at Google and the Janelia Research Campus in Virginia, took two years to create. The team started out by cutting a fruit fly brain into extremely thin slices using a hot knife — and then imaging each slice under an electron microscope. Afterward, they stitched the images together to create a large map, tracing the paths of the neurons through the brain, according to the statement.

[Continues . . .]
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


xSilverPhinx

Quote from: Recusant on January 24, 2020, 06:30:37 AM
The most highly detailed map (connectome) to date of part of a fruit fly's brain has been constructed. I don't know that the scientists who worked on this project who were not Google employees would appreciate the credit going to Google, but I suppose it makes for a more attention-grabbing headline.



"Google just created the most detailed image of a brain yet" | LiveScience

QuoteScientists have created the most detailed 3D map of an organism brain to date. The mesmerizing threads of blue, yellow, purple and green represent thousands of brain cells and millions of connections found inside the brain of a fruit fly.

This high-resolution map, known as a "connectome," only makes up one-third of a fruit fly's brain but includes a large region involved in learning, navigation, smell and vision. Scientists found over 4,000 different types of neurons, including those involved in the fly's circadian rhythm — or internal clock — that might help researchers learn a bit more about how the insect sleeps, according to the publicly released data.

This map, a collaboration between scientists at Google and the Janelia Research Campus in Virginia, took two years to create. The team started out by cutting a fruit fly brain into extremely thin slices using a hot knife — and then imaging each slice under an electron microscope. Afterward, they stitched the images together to create a large map, tracing the paths of the neurons through the brain, according to the statement.

[Continues . . .]

Next we'll be seeing Google Brain Maps.
I am what survives if it's slain - Zack Hemsey


Recusant

 :snicker: Thinking about Google's interest in this, I'm guessing that it's related to their development of AI.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


xSilverPhinx

Quote from: Recusant on January 30, 2020, 02:55:29 PM
:snicker: Thinking about Google's interest in this, I'm guessing that it's related to their development of AI.

That makes sense.
I am what survives if it's slain - Zack Hemsey


Recusant

Human brains are asymmetrical in specific ways. This study shows that other great apes display a similar brain asymmetry.

"Researchers Were Not Right About Left Brains, Study Suggests" | ScienceDaily

QuoteThe left and right side of the brain are involved in different tasks. This functional lateralization and associated brain asymmetry are well documented in humans, but little is known about brain asymmetry in our closest living relatives, the great apes. Using endocasts (imprints of the brain on cranial bones), scientists now challenge the long-held notion that the human pattern of brain asymmetry is unique. They found the same asymmetry pattern in chimpanzees, gorillas, and orangutans. However, humans were the most variable in this pattern. This suggests that lateralized, uniquely human cognitive abilities, such as language, evolved by adapting a presumably ancestral asymmetry pattern.

[. . .]

Brain asymmetry is commonly interpreted as crucial for human brain function and cognition because it reflects functional lateralization. However, comparative studies among primates are rare and it is not known which aspects of brain asymmetry are really uniquely human. Based on previously available data, scientists assumed that many aspects of brain asymmetry evolved only recently, after the split between the human lineage from the lineage of our closest living relatives, the chimpanzees.

In a new paper researchers from the Max Planck Institute for Evolutionary Anthropology and the University of Vienna measured the magnitude and pattern of shape asymmetry of endocasts from humans and apes. "Great ape brains are rarely available for study, but we have developed methods to extract brain asymmetry data from skulls, which are easier to access. This made our study possible in the first place," says lead author Simon Neubauer.

The team found that the magnitude of asymmetry was about the same in humans and most great apes. Only chimpanzees were, on average, less asymmetric than humans, gorillas, and orangutans. They also investigated the pattern of asymmetry and could demonstrate that not only humans, but also chimpanzees, gorillas, and orangutans showed the asymmetry pattern previously described as typically human: the left occipital lobe, the right frontal lobe, as well as the right temporal pole and the right cerebellar lobe projecting more relatively to their contralateral parts. "What surprised us even more," says Philipp Mitteroecker, a co-author of the study, "was that humans were least consistent in this asymmetry with a lot of individual variation around the most common pattern." The authors interpret this as a sign of increased functional and developmental modularization of the human brain. For example, the differential projections of the occipital lobe and the cerebellum are less correlated in humans than in great apes. This finding is interesting because the cerebellum in humans underwent dramatic evolutionary changes and it seems that thereby its asymmetry was affected as well.

[Continues . . .]
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Recusant

Never heard the technical name before, but "spindle neuron" sounds familiar. Some people poked them with ultra-fine tubes of glass, and learned things.  ;)

"Scientists Just Took a Closer Look at an Incredibly Rare Human Brain Cell Type" | ScienceAlert

QuoteYou'd be forgiven if you haven't heard of von Economo neurons (VENs) or spindle neurons, a rare type of human brain cell. But these cells are now at the centre of an exciting scientific development: researchers have recorded their electrical activity for the first time.

The discovery was made possible due to a delicate and demanding analysis carried out on brain cells donated to science by a Seattle woman in her 60s, who agreed to donate tissue removed during surgery on a brain tumour.

Unlike many other types of neurons, VENs aren't found in rodent lab animals such as mice and rats; they're even difficult to find in human brains, which means studying these elusive cells is a serious challenge.

"At this point we're really in the descriptive phase of understanding these neurons," says neurobiologist Ed Lein, from the Allen Institute for Brain Science in Washington. "There are still many remaining mysteries."

VENs are large and spindle-shaped (hence their alternative name), and are found in just three small regions of the brain. They also show up in great apes, whales, dolphins, cows and elephants, suggesting their presence could have something to do with being a social animal, or an animal with a larger brain in general.

People who get older without suffering the usual memory loss have been noted to have more VENs than normal; on the flip side, certain brain diseases seem to be associated with a loss of these types of neurons.

All of these factors have made VENs an intriguing subject for study - if only we could get a closer look at them more regularly.

In this case, the researchers had to hunt through thin slices of brain tissue to find the right neurons, and then carefully puncture them without breaking the outer membrane of the cells – an operation that allows electrical signals to then be captured. It wasn't easy.

[Continues . . .]

The full paper is available: "Transcriptomic evidence that von Economo neurons are regionally specialized extratelencephalic-projecting excitatory neurons" | Nature
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Davin

I've seen a picture of spindle neurons... calling them "spindle shaped" takes a pretty good imagination. Mine failed. They remind more of a tree stump and its roots, but "stump neurons" is probably not as catchy. Good read though, maybe with some more study they can eventually develop something to prevent their loss.
Always question all authorities because the authority you don't question is the most dangerous... except me, never question me.

xSilverPhinx

I don't like to make fun of mental or neurological illnesses so I didn't post this in any of the zombie, COVID or political threads, but you want to see something truly strange, look up Cotard's Syndrome.   :spooked:
I am what survives if it's slain - Zack Hemsey