Scientists create artificial brain out of spongy goo | Science/AAAS | News

Scientists create artificial brain out of spongy goo | Science/AAAS | News: The rings are engineered to mimic the structure and function of the six layers of human cortical brain tissue. Scientists coaxed neurons (right) to grow around stiff, porous matrices made of silk proteins immersed in collagen gel. Then, they colored the layers with food dye and pieced them together like a jigsaw puzzle. By tweaking the size and orientation of matrix pores, researchers attempted to emulate variations of cellular structure and function in a real cortex. Unlike flat neuron cultures grown in petri dishes, the structure provides cells with something to cling to as they branch out and make connections, forming complex, 3D networks that more closely mimic real neural circuits, the authors say.

Physicists eye neural fly data, find formula for Zipf's law

Physicists eye neural fly data, find formula for Zipf's law: ...George Zipf... found that if you rank words in a language in order of their popularity, a strange pattern emerges: The most popular word is used twice as often as the second most popular, and three times as much as the third-ranked word, and so on. This same rank vs. frequency rule was also found to apply to many other social systems...

"We showed mathematically that the system becomes Zipfian when you're recording the activity of many units, such as neurons, and all of the units are responding to the same variable," Nemenman says. "The fact that Zipf's law will occur in a system with just 40 or 50 such units shows that biological units are in some sense special – they must be adapted to the outside world."

Equations reveal the rebellious rhythms at the heart of nature

Equations reveal the rebellious rhythms at the heart of nature: Physicists Dmytro Iatsenko , Professor Peter McClintock, and Professor Aneta Stefanovska, have reported a far more general solution of the Kuramoto equations than anyone has achieved previously, with some quite unexpected results.

One surprise is that the oscillators can form "glassy" states, where they adjust the tempos of their rhythms but otherwise remain uncoordinated with each other, thus giving birth to some kind of "synchronous disorder" rather like the disordered molecular structure of window glass. Furthermore and even more astonishingly, under certain circumstances the oscillators can behave in a totally independent manner despite being tightly coupled together, the phenomenon the authors call "super-relaxation".

Human brain's ultimate barrier to open for first time - health - 18 June 2014 - New Scientist

Human brain's ultimate barrier to open for first time - health - 18 June 2014 - New Scientist: Next is a treatment called high-intensity focused ultrasound. The volunteers will wear a cap that contains an array of transducers that direct ultrasound waves into their brain. Just as the sun's rays can be focused by a magnifying glass, ultrasound waves can be concentrated inside the body to get the microbubbles to vibrate.

The vibrating bubbles will expand and contract about 200,000 times a second, which will force apart the endothelial cells that form the BBB. The idea is that this will allow the chemotherapy drug in the bloodstream to sneak through the gaps in the barrier and into any nearby tumour cells...

First Movie Of An Entire Brain’s Neuronal Activity — The Physics arXiv Blog — Medium

First Movie Of An Entire Brain’s Neuronal Activity — The Physics arXiv Blog — Medium: ...Schrödel, Prevedel and co developed a way to ensure that the genes only fluoresce in the nucleus of each neuron. That makes active neurons much easier to tell apart...

...light sculpting. This works by bouncing the spot of laser light off a grating that stretches it out. This creates a disc of light that images an area of the brain in one go rather than a single point. In affect, it produces a cross-sectional image of brain activtiy.

The advantage is that the light disc need only be scanned in one direction to capture the whole volume of the brain. And this can be done at a rate that allows the team to film the neuronal activity of the entire brain at a rate of 80 frames per second.

Synchronized brain waves enable rapid learning | MIT News Office

Synchronized brain waves enable rapid learning | MIT News Office:  Brain waves known as “beta bands,” produced independently by the prefrontal cortex and the striatum, began to synchronize with each other. This suggests that a communication circuit is forming between the two regions, Miller says.

“There is some unknown mechanism that allows these resonance patterns to form, and these circuits start humming together,” he says. “That humming may then foster subsequent long-term plasticity changes in the brain, so real anatomical circuits can form. But the first thing that happens is they start humming together..."

Previous studies have shown that during cognitively demanding tasks, there is increased synchrony between the frontal cortex and visual cortex, but Miller’s lab is the first to show specific patterns of synchrony linked to specific thoughts.

A Beautiful Mind: Brain Injury Turns Man Into Math Genius�

A Beautiful Mind: Brain Injury Turns Man Into Math Genius�: Padgett recalls being knocked out for a split second and seeing a bright flash of light...

Soon after the attack... he noticed that everything looked different. He describes his vision as "discrete picture frames with a line connecting them, but still at real speed." If you think of vision as the brain taking pictures all the time and smoothing them into a video, it's as though Padgett sees the frames without the smoothing. In addition, "everything has a pixilated look," he said.

Neuroscientists find cortical columns in brain not uniform, challenging large-scale simulation models | KurzweilAI

Neuroscientists find cortical columns in brain not uniform, challenging large-scale simulation models | KurzweilAI: The study was based on recent advances in high-resolution imaging and reconstruction techniques (confocal microscopy and automated image-processing routines)... enabling researchers to automatically and reliably detect the 3D location and type of every nerve cell throughout the entire brain...
“By determining the exact numbers and distributions of nerve cells within almost 100 cortical columns, the substantial differences observed across columns within the same animal argue against the principle of cortical uniformity.”

Nanoscale neuronal activity measured for the first time | KurzweilAI

Nanoscale neuronal activity measured for the first time | KurzweilAI: “The nanopipette hovers above the surface of the sample and scans the structure to reveal its three-dimensional topography. The same nanopipette then attaches to the surface at selected locations on the structure to record electrical activity.

Imaging most of a worm’s brain activity at high resolution and in a single operation | KurzweilAI

Imaging most of a worm’s brain activity at high resolution and in a single operation | KurzweilAI: Visualizing the neurons also requires tagging them with a fluorescent protein that lights up when it binds to calcium, signaling the nerve cells’ activity.

“The neurons in a worm’s head are so densely packed that we could not distinguish them on our first images...”

“Our solution was to insert the calcium sensor into the nuclei rather than the entire cells, thereby sharpening the image so we could identify single neurons.”

Stem cells mimic human brain : Nature News & Comment

Stem cells mimic human brain : Nature News & Comment: ...in the latest advance, scientists developed bigger and more complex neural-tissue clumps by first growing the stem cells on a synthetic gel that resembled natural connective tissues found in the brain and elsewhere in the body. Then, they plopped the nascent clumps into a spinning bath to infuse the tissue with nutrients and oxygen...

Under a microscope, researchers saw discrete brain regions that seemed to interact with one another. But the overall arrangement of the different proto-brain areas varied randomly across tissue samples — amounting to no recognizable physiological structure.

“The entire structure is not like one brain,” says Knoblich, adding that normal brain maturation in an intact embryo is probably guided by growth signals from other parts of the body. The tissue balls also lacked blood vessels, which could be one reason that their size was limited to 3–4 millimetres in diameter, even after growing for 10 months or more.

Researcher controls colleague’s motions in 1st human brain-to-brain interface | UW Today

Researcher controls colleague’s motions in 1st human brain-to-brain interface | UW Today: ...Rao sat in his lab wearing a cap with electrodes hooked up to an electroencephalography machine, which reads electrical activity in the brain. Stocco was in his lab across campus wearing a purple swim cap marked with the stimulation site for the transcranial magnetic stimulation coil that was placed directly over his left motor cortex, which controls hand movement...
Rao looked at a computer screen and played a simple video game with his mind. When he was supposed to fire a cannon at a target, he imagined moving his right hand (being careful not to actually move his hand), causing a cursor to hit the “fire” button. Almost instantaneously, Stocco, who wore noise-canceling earbuds and wasn’t looking at a computer screen, involuntarily moved his right index finger to push the space bar on the keyboard in front of him, as if firing the cannon. Stocco compared the feeling of his hand moving involuntarily to that of a nervous tic.

Video: Near-Whole Brain Activity Map in Fish | MIT Technology Review

Video: Near-Whole Brain Activity Map in Fish | MIT Technology Review: ...researchers reported that they were able to watch the individual activity of nearly all the neurons in a fish’s brain at the same time...

Now, HHMI has put together a video about the work, and it’s worth a look. Neuroscientist Philipp Keller explains how some of the technology behind the experiment works. Best of all, we get to see more of the complex flickering constellations of brain cells—fish thoughts in action. This work is the first time researchers have been able to look at the activity of nearly all neurons in a vertebrate brain.

How to reconstruct from brain images which letter a person was reading | KurzweilAI

How to reconstruct from brain images which letter a person was reading | KurzweilAI: The researchers “taught” the model how 1200 voxels (volumetric pixels) of 2x2x2 mm from the brain scans correspond to individual pixels in different versions of handwritten letters...
“In our further research we will be working with a more powerful MRI scanner,” said Sanne Schoenmakers, who is working on a thesis about decoding thoughts. “Due to the higher resolution of the scanner, we hope to be able to link the model to more detailed images. We are currently linking images of letters to 1200 voxels in the brain; with the more powerful scanner we will link images of faces to 15,000 voxels.”

How neurons ‘decide’ to create axons or dendrites | KurzweilAI

How neurons ‘decide’ to create axons or dendrites | KurzweilAI: They found that embryonic nerve cells manufacture a signaling enzyme called Atypical Protein Kinase C (aPKC) in two varieties: a full-length one and a shorter one...
When the researchers blocked the production of the short form, the nerve cell grew multiple axons and no dendrites. When they created an artificial abundance of the short form, dendrites formed at the expense of axons.

Flatworms lose their heads but not their memories: Study finds memories stored outside the brain

Flatworms lose their heads but not their memories: Study finds memories stored outside the brain:
Automated video tracking and subsequent computer analysis of the worms' movements (image above) showed that the group familiarized to the rough-floored dishes overcame aversion to the light significantly more quickly and spent more time feeding in the illuminated space than did the non-familiarized group...

Both groups of worms were then decapitated and housed in a smooth-floored environment while their heads regenerated. Two weeks later, the fully regenerated segments were again tested. Worms regenerated from the familiarized group were slightly but not significantly quicker to feed in the lighted part of the container. However, when both groups of worms were given a brief refresher session of feeding in the textured environment, then removed and retested four days later, the planaria generated from familiarized segments were significantly quicker to feed than those regenerated from unfamiliarized worms—showing that they retained recognition of the link between this type of surface and a safe feeding environment.

A Videogame That Recruits Players to Map the Brain | Wired Design | Wired.com

A Videogame That Recruits Players to Map the Brain | Wired Design | Wired.com: Created by neuroscientist Sebastian Seung’s lab at MIT, EyeWire basically gamifies the professional research Seung and his collaborators do on a daily basis.

Decapitated worms regrow their heads with old memories intact

Decapitated worms regrow their heads with old memories intact: to embed a specific memory, the researchers spent 10 days teaching the flatworms that food could be found at the center of a petri dish with a light shining on it...

Then their heads were chopped off...

Once their heads and brains grew back, the scientists threw them back into the petri dish. But the memory wasn’t there right away. And in fact, the biologists had to give the worms a refresher course on the matter of finding food — but one quick lesson was all it took; the lesson basically allowed the worms to refresh their memories. Subsequent trials showed that the previously decapitated worms reached the food significantly faster than those (previously undecapitated) worms who were also given the benefit of one training session.

Many Neuroscience Studies May Be Based on Bad Statistics | Wired Science | Wired.com

Many Neuroscience Studies May Be Based on Bad Statistics | Wired Science | Wired.com: Many researchers consider a statistical power of 80 percent to be a desirable goal in designing a study. At that level, if an effect of a particular size were genuine, the study would detect it 80 percent of the time.

But roughly half of the neuroscience studies Munafò and colleagues included in their analysis had a statistical power below 20 percent. Those studies would fail to detect a genuine effect at least 80 percent of the time...

“It was already clear that fMRI studies were almost always very underpowered, but this paper shows that just about everything except a set of studies described as “neurological” are also underpowered,” Pashler said.

Brain imaging spots our abstract choices before we do

Brain imaging spots our abstract choices before we do:  Kreiman discovered that electrical activity in the supplementary motor area, involved in initiating movement, and in the anterior cingulate cortex, which controls attention and motivation, appeared up to 5 seconds before a volunteer was aware of deciding to press the button (Neuron, doi.org/btkcpz). This backed up earlier fMRI studies by John-Dylan Haynes of the Bernstein Center for Computational Neuroscience in Berlin, Germany, that had traced the origins of decisions to the prefrontal cortex a whopping 10 seconds before awareness...

If this kind of "mind-reading" is possible, a new study by Haynes, published this week and also presented at the meeting, suggests that it may not be restricted to decisions about moving a finger. Using fMRI, Haynes has found that the very brain areas involved in deciding to move are also active several seconds before a more abstract decision, like whether to add or subtract a series of numbers.