The connections between neurons inside a Cortical Column.
A bionic prosthetic eye that speaks the language of your brain
This is both fascinating and interesting …
A scientist talks about their work on prosthetic sight, working on a technique which could potentially benefit not only other prosthetic technologies, but also understanding of the brain.
Sheila Nirenberg seems to have successfully managed to create a visual encoder placed on the optic nerve which can transcode visual stimuli into a signal into the brain. From Extreme Tech:
Now, reading the brain’s output (as in a prosthetic arm) is one thing, but feeding data into the brain is something else entirely — and understanding the signals that travel from the retina, through the optic nerve, to the brain is really about as bleeding edge as it gets. Nirenberg still used a brute force technique, though: By taking a complete animal eye and attaching electrodes to the optic nerve, she measured the electric pulses — the coded signal — that a viewed image makes. You might not know what the code means, but if a retina always generates the same electric code when looking at a lion, and a different code when looking at a bookcase, you can then work backwards to derive the retina’s actual encoding technique.
Perhaps even cooler, though, Nirenberg insists that this same technique — wiring up electrodes to our sense organs and brute forcing the encoding technique — could also be used to produce prosthetic ears, or noses, or limbs that can actually feel. Presumably, at some point, with enough data points under our belt, we might begin to unravel the human brain’s overarching communication codecs, too.
Neurophysicists to everyone: “There is an optimal brain frequency”
We may be familiar with the concept of electrical/chemical signals relating to neural communication. So, now imagine of every synapse branching out from every neuron - like an antenna, is tuned to a different frequency signal with a specific optimal point and this optimum frequency point depends on the location of the synapse on a neuron. The farther away the synapse is from the neuron’s cell body, the higher the optimum frequency was found to be. And it seems the more rhythmicly synced the frequencies were - the stronger the connection for memory and learning synapses.
The researchers found that not only does each synapse have a preferred frequency for achieving optimal learning, but for the best effect, the frequency needs to be perfectly rhythmic — timed at exact intervals. Even at the optimal frequency, if the rhythm was thrown off, synaptic learning was substantially diminished.
Their research also showed that once a synapse learns, its optimal frequency changes. In other words, if the optimal frequency for a naïve synapse — one that has not learned anything yet — was, say, 30 spikes per second, after learning, that very same synapse would learn optimally at a lower frequency, say 24 spikes per second. Thus, learning itself changes the optimal frequency for a synapse.
As well as possibly strengthening and enhancing learning and memory, learning-induced re-tuning and de-tuning could be have “important implications for treating disorders related to forgetting, such as PTSD disorder”. via
The image shows a neuron with a tree trunk-like dendrite. Each triangular shape touching the dendrite represents a synapse, where inputs from other neurons, called spikes, arrive (the squiggly shapes). Synapses that are further away on the dendritic tree from the cell body require a higher spike frequency (spikes that come closer together in time) and spikes that arrive with perfect timing to generate maximal learning. VIA
cwnl:
Scientists turn up startling diversity among nerve cells
Peer out the window of a plane landing at LaGuardia Airport, and the tiny people scurrying around the streets of New York City all look the same. But take a stroll down Fifth Avenue and a new view emerges: Up close, New Yorkers are very different.
A street view of the brain also reveals a new perspective: No two cells are the same. Zoom in, and the brain’s wrinkly, pinkish-gray exterior becomes a motley collection of billions of cells, each with personalized quirks and idiosyncrasies.
Powerful new techniques are giving researchers a glimpse of this staggering diversity — especially among nerve cells, the brain’s information brokers. Even nerve cells presumed to do the same job come in a range of shapes and sizes and display a host of behaviors, sending their electrical messages in unpredictable ways, new studies reveal. The closer scientists scrutinize nerve cells, called neurons, the more differences turn up.
This cellular menagerie has left researchers puzzling over how best to categorize what neuroscientist Rafael Yuste of Columbia University calls these “living creatures.” So far, systematic methods are lacking. “Even after 100 years of research, we have no clue how many classes of neurons there are,” says Yuste, a Howard Hughes Medical Institute researcher. He and other scientists are developing new algorithms to automate neuron classification, in the hope of someday compiling a standard “parts list” of the brain.
While some scientists are hard at work categorizing all these different cells, others are thinking about what such diversity means for living, breathing animals. New results suggest, for instance, that a population of nerve cells in which individual responses to an electrical poke differ can process more information than a group in which responses are the same. Others think that variety might help the brain cope with a changing environment.
Accounting for all of the individual brain components — a task as daunting as finding out every New Yorker’s favorite color, credit score and whether they cry at sad movies — isn’t just a tedious sorting job. A deeper knowledge of the brain’s inhabitants might lead to new treatments for brain-related disorders. If particular cells are more vulnerable to diseases such as dementia, schizophrenia and autism, therapies that protect or target these cell populations may be effective. More broadly, knowing who is doing what in the brain will help scientists understand the inner workings of the impossibly complex three-pound hunk of flesh that sits in the skull.
(via narvanonthebridge)
Source: sciencenews.org
cwnl:
An Odyssey Through the Brain, Illuminated
“Portraits of the Mind: Visualizing the Brain From Antiquity to the 21st Century,” newly published by Abrams, includes short essays by prominent neuroscientists and long captions by Mr. Schoonover — but its words take second place to the gorgeous imagery, from the first delicate depictions of neurons sketched in prim Victorian black and white to the giant Technicolor splashes the same structures make across 21st-century LED screens.
Visit Slideshow Highlighting The Images Here
Full article after source
(via narvanonthebridge)
Source: The New York Times
Activated microglia, astrocyte, and pyramidal neuron in rat hippocampal slice culture. (via Michael Dailey Image Gallery)
The multicolored neurons sit in the cerebral cortex, which is involved in higher thought processes and sensory perception. To create a unique color in each neuron, Lichtman did some clever genetic tinkering: He inserted the genes for different-colored fluorescent proteins into the mouse’s genome so that each neuron would randomly express a combination of the genes. It ends up being a game of chance: Each neuron is essentially pulling the lever on a “molecular slot machine,” says team member Jean Livet, receiving a random combination of the genes that endow it with one of 90 possible colors.
cwnl:
The Stuff of Dreams
By CWL (Ken)
What are dreams? Why do we have them? How can you become lucid and Why
Dreaming is a natural process just about every conscious animal undergoes each night during sleep. Many believe dreaming is merely an act of the brain trying to keep you asleep and occupied as your body regenerates and makes up for the dead cells your body got rid of during the day. A way of keeping our bodies nice and strapped. Our bodies literally paralyzes itself once you go into heavy sleep, so that in case your dream becomes too wild, you don’t end up acting it out as you sleep. That was but a mere brief look at what goes on with dreams at the physical level.
What goes on In The Mind?
Each night we lay to rest and slip into Rapid Eye Movement (REM) which is the state of consciousness when one is dreaming away we never realize we are literally falling into our own mind’s ocean of thoughts and data, memories all in a vast ocean generated by our Neural System. It is not just a simple movie created out of your deepest desires, in fact most dreams have little to do with desires and more to do with revelations and mending.
What Really Goes On
Just like at the physical level, when someone is hurt and scarred and starts to bleed, as the blood begins to quickly dry to begin the healing process. Some what of the same goes on at the mental level, as there are two sections of the mind that aid those lingering thoughts. The conscious and awake, and the Subconscious and subtle. The conscious sorts that which you live through in the present in the now, and sends off signals to the memory, the subconscious then looks through these memories whether their short on long term and sort them out by priority according to the person. That is to say, it files it for later use for when you are asleep. Once asleep, it brings these back up in the format of dreams. So in other words, your thoughts and concerns become a movie or video game you must play through them.
Why Do We Dream?
This happens for the simple fact that if that mental wound is left untreated, it will become infected. By this I mean a thought becomes corruptive and seemingly harmful to the person if left in the back of the mind, and so the subconscious throws you into a pit with your own thoughts so that you may overcome them and continue your humanly processes in the next day as you wake conscious. Without dreams we’d all go mad, this is science fact. Without dreams all of our thoughts would be corrupting our minds to the point where the brain becomes stressed and under performs.
Next Up: The Stuff of Dreams Part 2- Lucidity and Its Benefits
Sex on the brain: Orgasms unlock altered consciousness
In the holy name of science, a reporter goes into a fMRI machine to masturbate to help researchers ”tease apart the mechanisms underlying sexual arousal. In doing so, not only have they discovered that there is more than one route to orgasm, but they may also have revealed a novel type of consciousness - an understanding of which could lead to new treatments for pain ” since orgasm is a strong analgesic experience.
Eyeballing the prefrontal cortex, the researchers are hopeful this may shed light on thoughts can control pain through top-down pain relief methods.
This kind of research is incredibly useful,” says Heiman. “Orgasm is tied into the brain’s reward system and likely other important systems as well. There is much we can learn about the brain, about sensation, about how pleasure works and probably much more from this one physical response.” Via
Image above: how the “…reporter’s brain looks like at the moment of orgasm. The scan is a sagittal section, essentially a profile shot, that shows one moment in time in different “slices” through the brain…” like a composite. The warmer the colors, the more blood flow present indicating activation in that area of the brain over 30 areas here…you can see that orgasm is nearly an entire brain event.
ALSO? People were able to “control pain by watching real-time activity of a brain area called the rostral anterior cingulate cortex (ACC) and then mentally adjusting it”, Stanford University researchers say. This resembles Eagleman’s prefrontal gym.
Updated Guidelines for Diagnosing Alzheimer’s | NYTimes.com
For the first time in 27 years, the definition of Alzheimer’s disease is being recast in new medical guidelines that reflect fast-mounting evidence that it begins ravaging the brain years before the symptoms of dementia.
The guidelines, to be issued Tuesday by the National Institute on Aging and the Alzheimer’s Association, divide the disease into three stages: a phase when dementia has developed, a middle phase in which mild problems emerge but daily functions can still be performed, and the most recently discovered phase, in which no symptoms are evident but changes are brewing in the brain.
“We’re redefining Alzheimer’s disease and looking at this in a different way than had ever been done,” said Creighton Phelps, director of the National Institute on Aging’s Alzheimer’s Disease Centers Program. “I think we’re going to start to identify it earlier and earlier.”
