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Use All Your Brain, Not Only Neurons?
SEWilco writes: "Iowa State researchers found evidence that glial cells communicate in the brain. Previously it was thought that the neurons were active, but glial cells were only structural and nourishment objects. Apparently glial cells can influence neighboring neurons at least through glutamate signals. Details in the Proceedings of the National Academy of Sciences. Maybe we still have a little more to learn about biology." I know, it's my second 'science question' headline of the day, but heck, most science headlines should end with a question mark.
I know that biology isn't a mainstream Slashdot topic, so people's ignorance on the subject is understandable. But if you don't understand it, then please don't make a post about - there really is no need to broadcast your ignorance to the world. And the same applies to moderators - don't moderate it up if you don't understand what the post is getting at - you make the Slashdot community appear to be stupid, and annoy the hell out of those of us who are familiar with the subject matter.
Chmrr,
The material that covers the axons of the neurons is myelin, not glial cells (see http://www.dictionary.com/cgi -bin/dict.pl?term=myelin.
Myelin allows the chemical-electrical transmission to happen in a more "productive" manner. Faster and better neurotransmissions from one neuron to the next.
Glial cells are the support structure, but myelin is separate. Glial cells are not neurons. I guess now their finding that Glial cells do more than just support and can influence neurons cells in certain ways. If you ask me this isn't that extrodinary, because the more glial cells you have around the neurons, the better off things are so its obvious the glial cells influence neurons in some way. I guess we're just getting more knowledgable about how.
Maybe by the time I get this post in someone will have explained it better but I'll add my 2 cents anyways and expand on Chmrr's explanation. The computer mouse analogy works well. The mouse is a neuron. The big plasic chunk is the body of the neuron, and the tail is the axon. On the body are little strands which extend out to "touch" the axons of other neurons. When the neuron gets enough impulses from other neurons through the little strands (called dendrites) the neuron body fires a charge down the axon (mouse cord) off to one other neuron.
If the head had grown up attached to a body, the basic thought patterns and capacities would be similar, though would change in ways similar to those who grow up normal, then become quadraplegic through accident. A head in a jar (BIV for you h.p.o readers) raised that way would likely think in very different ways, though.
" I'd like to know if there's evidence that glial cells also have functional calcium uptake pumps and if their level of calcium fluctuates with blood level or remains constant..."
Glial cell (C6 glioma) calcium levels fluctuate with that of the external medium. Changes of a few mM produce cytosolic changes on the order of 10's of nM (J. Phyiol. several years ago). In vivo...who knows?
"While this is interesting news, it's certainly not true that we ever thought of glia as (in the
words of the press release) "little more than glue." "......
Before 1950, some researchers confused the extracellular space in the brain with glial cells. The 'space' was actually cellular.
Unfortunately, glial electrophysiological characteristics did not, do not, lend themselves to sustained, fundable study. i.e., where's that action potential? This glial cell calcium story, and the many other glial calcium studies, may help change some perceptions.
I agree with you: current thinking is astrocytes are good for you when you're developing your brain (providing pathways to guide neurons to 'final' destinations) but 'bad', if you're an adult who has a penetrating nerve-killing injury.
Biological neurons are extremely complicated. In fact Hodgkin and Huxley received a Nobel prize for modelling a giant squid axon in 50s. They used three partial differential equation to describe a simple neuron. And even that description was far from complete. In fact I don't think even now there is a realistic comprehensive model for cell interactions in the brain.
Nobody knows much about their computational capacity or how they do computations and transmit information.
Artificial neurons in neural nets are exceedingly crude approximations to the real thing.
His reasoning goes as following:
Thought process is a mystery to me and I want to belive that it cannot be described by a Turing machine. Well, let's substitute one mystery with a different one (i.e. quantum mechanics), which is not predictable and hence is not a Turing machine. I win.
Wishful thinking coming from a respected scientist...
While I'm very happy that Jennifer Dukes Lee (who I met during my brief days at the Iowa State Daily) made Slashdot (go Jenny!), I'm not seeing the news value of a discovery whose significance was recognised "in a 1994 scientific journal called Cell." Just wondering about that.
Hi. Read this: http://www.kuro5h in.org/?op=displaystory&sid=2000/7/18/122257/231. Please don't b-slap me; this is important!
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He lives in a world where those who do not run the client software of the omnipresent meme are unacceptable.
Offered by physicist Penrose who says "I'm too stupid to figure out the complexity of the brain, so I'll confound things with mumbo-jumbo physics".
Before you jump to conclusions you should note that every system is a quantum system. That is the whole point of physics; a unified model of the universe. It's not like "an electron is a quantum system and an apple isn't".
A similar argument is that quantum effects are only evident on a small scale or at low temperatures. The freakin computer you're using to read this shifts macroscopic amounts of charge in a way that can only be explained by quantum mechanics. See Nature, 406 p43 for an example of macroscopic quantum superposition.
For the relationship between quantum computation and (classical) Turing machines see Deutsch, 1985 in Proceedings of the Royal Society of London 400 (pp97-117). It seems all that "mumbo jumbo physics" may actually play a role in this after all.
To me it seems ridiculous and unimaginative to assume that even though QM is fundamental to the structure of the universe and seems intimately connected to consciousness (google: "Wigner's friend";"Schroedinger's cat";"measurement problem"), consciousness is strictly a classical phenomenon.
Dave
This is exactly the point. They had no valid evidence that suggested that neurons to not regenerate. If they did have evidence to suggest that, then by definition it's not valid "evidence" and their methods are severely flawed. If they didn't have evidence and just made something up, such as "well, it doesn't look like the regenerate, so we'll just say that they absolutely do not reproduce", which seems to be what you're suggesting, then they are not scientists by any stretch of the imagination.
I recall very specifically of reports in text books, technical literature and even science shows on TV and in other mass media stating in very clear and specific terms that neurons do not regenerate. I believe I was even taught this in school. Since this is wrong, they must have had no valid evidence to base this on, and preferrably should not have spread lies to so many millions of people.
Some other sites exploring maximizing the possibility of the human mind:
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Seems to work fine on Futurama. :)
For years I heard that the brain *never* regenerates cells. The brain cells that you're born with are the only ones you will ever get. Now, it is known that is completely wrong. The brain does have the ability to regenerate brain cells that are lost.
Well, actually the brain is rather odd in that it doesn't have the same regenerative capacities as the peripheral nervous system. A patient with brain damage never recovers fully. Sometimes new dendrites (branches) are formed by remaining neurons to help, sometimes the patient can learn other ways of completing the same task, but generally there is little regrowth of damaged tissue. However you are right in saying that new brain cells are produced (there are many theories describing the purpose of these new [and sometimes temporany] cells), however full regrowth of damaged tissues has not been observed.
Complexity Happens
Some speculate that some of the brain's functioning occurs at a quantum level inside of the microtubules inside of neurons (e.g., Penrose). The notion is that quantum effects are necessary to tie the disparate processes of the brain together simultaneous, in other words consciousness. AFAIK, glial cells do not have microtubules so they wouldn't be involved in these proceses.
In very well controlled, scientific experiements, the parts of the human brain responsible for processing visual information have been found to activate few milliseconds before the actual light signal has been delivered to the eye
Howsabout giving us a citation on that? I'm a bit sceptical about this, having studied cognitive science for the past four years and heard nothing about this magnificent, knock-down argument for quantum processing...
That was bitchy. Sorry.
/bluesninja
Its true, he had twice as many glial cells, and at the time of his death, nobody knew why or if it had an impact on his intelligence.
This should not be that sensationalistic. There has been speculation for quite some time now that glial cells do more than "hold stuff together"
The major functions of glial cells have long been known to be "supportive" of the communication functions of neurons. To accomplish this, there are several types of glial cells in the central neurvous system (CNS). Some of them (Oligodendrocytes in the CNS and Schwann Cells in the peripheral nervous system (PNS) form myelin sheaths, which are insulative wrappings around axons that allow the axons to conduct information more rapidly and in isolation from each other to prevent cross talk. Other types of glial cells regulate the composition of extracellular fluids, assist neurons in metabolic activities, and participate in various humoral functions within the CNS.
In development, glial cells provide critical support functions for neurons such as guiding developing neurons to the right places in the brain and at the right time as well as functioning as a storehouse for neurotransmitter precursors and energy reserves for active neurons.
It has long been known that glial cells regulate the amount of neurotransmitter in the synapse by uptake of neurotransmitter and buffering of Calcium in the synapse as well which is critically important to synaptic release. Signaling in the CNS could certainly be influenced by the speed at which available neurotransmitter is taken up and also calcium. Many glial cells also have receptors for neurotransmitters and may play a role in the co-incident release of various traditional and non-traditional neurotransmitters or neuromodulators.
It should also be noted that glial cells also play a very intimate role in the recycling of neurotransmitters such as glutamate, where they convert glutamate into other metabolites that neurons can use for metabolism or neurotransmission. This too can influence cell state and thus signalling.
Finally there is some limited evidence on the electron microscopic level that there are actual synapses on neurons from glia. If true this indicates a more direct and speedy communication between glial cells and neurons.
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Well, don't blame the scientists if the popularised science makes it all sound too clear cut. And regarding the text books, how do you think it would sound to an already bored high school student if the science books would endlessly speculate whether this or that theory is correct. People who write those books have to draw the line somewhere and call the present knowledge as "the truth". The strong stuff (=the fact that in reality we know very little about anything) is left to those who decide to pursue a scientific career.
I am a professional scientist. For every answer I get from my research, there are always more questions. It just never ends and you can never be sure.
I remember Schwann cells contain a lot of fat, which is white. I'm not sure why - might be that fat is a good electric or chemical insulator. The white-gray colouring of the brain is their product (neurons are gray); very long axons connecting the gray cortical regions are covered by myelin sheaths, to increase the speed of the transmissions.
Not enough hours in the day, so maybe this will compensate
Do your best, hope for the best, suspect the worst.
No kidding. I just got done with my med school neuro class and we had a seminar on how glial cells are responsible for all sorts of things, including ionic balance, nerve regeneration, rapid uptake of secreted neurotransmitters, and, yes, even communication. It always seems that whenever the media pays attention to a science topic, they like to say things about how it opposes conventional wisdom. I'm not sure what that accomplishes, though. I guess they just like scientists to be wrong...
Invicta{HOG}
Actually, they had gross evidence about neuron growth. Wounds to the brain (and the spinal cord) do not repair themselves the way many many other body parts do. Well, now we know there is some repair ability, although there are limits on large-size repairs -- particularly as it's complicated by neuron/axon deaths and scar tissue.
There's a quite interesting couple of pre-prints in the arXiv dealing, in part, with the similarities between quantum logic (not quite the same thing as quantum computing) and cognition. (And don't forget that pre-prints can range from pure nonsense to wonderful - I'm not clever enough to tell where these particular ones lie on that spectrum)
arXiv.org/abs/quant-ph/0007044 - We show how Bell inequalities can be violated in cognition, specifically in the relationship between abstract concepts and specific instances of these concepts. This supports the hypothesis that genuine quantum structure exists in the mind.
To even vaguely understand the above, you'll need to read:
arXiv.org/abs/quant-ph/0007041 Why the Disjunction in Quantum Logic is Not Classical
Choice of masters is not freedom.
It has been speculated that quantum computing effects may occur in the brain. However, as I understand it, the current conventional wisdom is that such effects are minimal at best, and do not impact on the overall result of brain function.
Unfortunately, we will never know until we take a very smart person and run their brain through a particle accelerator and watch the effect as it smashes into a solid block of steel. Any volunteers?
Aah, change is good. -- Rafiki
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wow... a rediscovered kind of First Post (literally)!
;-)
If this theory is true, apendicitis (sp?) would be one heck of a migraine
It's very unlikely though... our brain is very well protected from external factors of most kinds. On the contrary, our guts are very close to huge sources of infection, and not strongly protected.
My guess is that we have to be very carefull with all the shit that goes trough there, so, it's highly monitored to raise the alarms asap if needed.
Gerry -- #include "ea!.h"
If the brain didn't regenerate its cells, we would all be brain dead from stress already. So all those neuron scientists can go kiss themselves. And how much of our brain is glial anyway? If it's about 20%, I might pay a little more attention.
Life is a waste of time, time is a waste of life, so get wasted all the time and have the time of your life.
Thanks for the interesting reply. Of course it was foolish of me to say that we never thought of glia as inert...
current thinking is astrocytes are good for you when you're developing your brain (providing pathways to guide neurons to 'final' destinations) but 'bad', if you're an adult who has a penetrating nerve-killing injury.
Funny how often we have to fight against the fruits of evolution when trying to do unreasonable things like transplant organs, travel in microgravity, and live 140 years...
- Michael Cohn
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The microtubules argument of Penrose has been multiply rebuffed since it was first proposed, at least based on what I've heard. I'll try and dig up the synopsis from my copy of Beyond Humanity and post it.
You owe the Zombie Oracle a slice of Broca's brain. ARrrRRRgh pick-uhled braaaaainsARrrrGHhh.
-TBHiX-
http://www.brains4zombies.com
aw come on, that's not fair.
:)
the fact people are thought stuff in school is not because the teacher happens to be an all knowing god with perfect knowledge of whatever he mumbles.
I'd have expected a little more nuanced view from a scientist like you. You know as good as the next guy that someday someone is going to ask 'why' and 'how' in some area, he tries to understand it, builds a new theory, and then maybe things move on, even if your first idea is way off-target. Don't forget that science is in no way whatsoever a mechanical straight into the new goal. It's a big excursion with questions and idea's floating around.
I was told at school that allmost any cell in c can allways regenerate, but due to specific factors, some are more apt then others. It had to do with the environment in which a cell resides, evolution of certain hormones, etc.. but I'm no biologist, so I'm not going to burn my fingers here
maybe the neuroscientists were dead wrong, yes, but hey, it took, what, 13 centuries to notice the earth not being flat at all ?
With great power comes great electricity bills.
The main problem is that what you hear in the popular press does not convey all of the uncertainties and caveats of the scientific literature. So a statement along the lines of "There is no clear evidence of neuronal regeneration in adult mammalian brain" becomes "Neurons can't regenerate." Of course, this was not merely an assumption--people had looked for regeneration and failed to find it. But absence of evidence is not evidence of absence. If you fail to find something, it may be that you are looking in the wrong place, with the wrong method, or simply that your technique isn't sensitive enough. And in fact, there was some evidence that occasionally new nerve cells might be "born;" it just wasn't very convincing evidence. And it was known that neurons regenerate in certain brain regions of certain birds, and in olfactory epithelium, so it clearly wasn't an absolute impossibility. So the latest results simply provide evidence of something that a lot of people suspected before, but couldn't prove.
The glial story is similar. It's been known for years that glial cells have neurotransmitter receptors and that they can release neuroactive substances, so a lot of people suspected that they play a role in neurotransmission. They just couldn't prove it, because most of the effects observed were either small, or required somewhat extreme conditions. The new report comes closer to demonstrating that glial neurotransmitter release can occur under physiologically relevant conditions, but it probably won't convince everybody. The real skeptics will insist on direct evidence that this glial function actually plays a role in neural function--perhaps by somehow knocking out this glial feature and demonstrating some kind of cognitive deficit.
AARrrgh Arrrgh brains good! AArrrrgh Glial cells add flavour. Arrrgh.
-TBHiX-
Hmm, most Neural Network models are based around a series of interconnected neurons. I wonder what impact this new discovery might have on them - maybe with glial cells modelled in software, and some hairy mathematics, our neural nets might become more powerful?
I didn't flunk biology, but I still can't decipher what they heck they're talking about?! I'm sure others on slashdot may be in the same position. This definately sounds interesting, though.
kick some CAD
How do we get these glial cells to communicate with the airport antennas on my new G4 Cube so I can use my brain as a processor?
Does it occur to anyone that neural scientists are making too many assumptions?
For years I heard that the brain *never* regenerates cells. The brain cells that you're born with are the only ones you will ever get. Now, it is known that is completely wrong. The brain does have the ability to regenerate brain cells that are lost. I was always skeptical and I was not surprised that the brain happens to do what every organ in the body already does. I think it would be quite remarkable if the brain was unique in that way.
Now we find out that cells which the common wisdom classified as stuctural members turn out to actually have some communications functions built into them. I remember reading about this years ago, and I was skeptical about that too. At the very least, the structural cells would have *some* impact on neural activity, and therefore must be considered as part of the computational structure of the brain.
I'm not sure where it's coming from though. Neural science draws from other disciplines, including psychology and medicine. One could argue that both of those subjects are still in the process of hacking their way out of their unscientific origins. I wonder if the half-completed scientific revolution in those subjects is hindering progress in understanding the brain.
To be fair, artificial inteligence is also a contributer to neural science which is probably even farther in the dark ages than either psychology or medicine.
Disclaimer: my wife is a psychologist. My comments are not meant as flamage, so if you're getting mad, contact me so I can clarify what I mean.
If tits were wings it'd be flying around.
The article makes it sound like everything is in black & white. Those of us who are more experienced biologists know that it's really a gray matter.
I need a TiVo for my car. Pause live traffic now.
Parts of the brain long viewed as little more than the glue that holds neurons together might be more important than we think.
So does this all mean that we should sniff more glue?
Hrmm.. Maybe I'll see increased performance if I start using these. My hardware dates from the late 1970s and I'm always looking for ways to keep it up to date with the newer models.
wish
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I heard somewhere that Einstein's brain had a lot more glial cells than normal, but at that time no one knew if that was a factor in his intelligence.
That was the funniest comment of the week! Why did I waste my moderator points on other, lesser comments?
Save the whales. Feed the hungry. Free the mallocs.
It should be noted that all cells communicate with nearby cells. This is an important part of our ontogeny (growth), and function. Therefore it's rather obvious that neurons communicate with glia cells at least somehow.
It should be noted that the glia cells do not necessarily perform any neural computation:
"Pathophysiological" means "unnatural". Anyhow, it might be just signaling that guides how the neurons or glia cells grow (during our ontogeny or afterwards). The changes in activation of the nearby neurons might be just a side effect, although it would nevertheless affect their computations, if the glutamate is actually released at postnatal (after birth) age (I understood that this is not known).- A novice artificial neural networks researcher who knows only very very little about neurobiology
I get it. It's the electromagnetic radiation from the hardware, that stimulates the glial cells, leading to a cascade of neuronal responses, fomenting the neuromuscular chain reaction that culminates in hitting the BID button on E-bay. No wonder the economists couldn't figure it out. They only assume rational utility maximizers.
Offered by physicist Penrose who says "I'm too stupid to figure out the complexity of the brain, so I'll confound things with mumbo-jumbo physics".
I wonder if one day engineers (maybe even now, biological, chemical, genetic and people in the biometrics field) will be able to describe the brain's (or other organ functions) with Verilog or VHDL (or some description language)? That would be an impressive code.... if you can model that you couldn't you apply it to creating and debugging more complex and efficient neural networks and other AI sub-products?
Yes it would be hard to do it now, but for a behavioral / abstract structural design, how much do we really need to know, to implement?. Anybody think there is a low level way to get it done withtin the next 20 years? I am terribly curious
It would by a heck of a long way off but it would be interesting.
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And lets just say, the uni's, um, 'lax' policy about their network is very nice. ISU student's don't even need napster.
Ok, let me try to make this ontopic... The artical said that the glial cells influince 'surounding' neurons, not neurons connected to it. I wonder if the techniques used by the glial cells can be used by artificial systems so that all we have to do is put stuff in the brain rather then actualy make nuruon connections. Of course, I have no clue, since I know nothing about nural biology.
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Do you think that a head in a jar would think in the same was [sic] as when it was attached to the rest of the body?
The short answer is yes. If the brain is still intact and provided with the proper nutrients, oxygen, etc. it should function no differently then before.
The lack of a body will mean the lack of any stimuli from the body. Thus the brain's 'intuitive senses' (i.e. 'gut feel') will no longer have any effect on the output of such a brain.
This seems similar to someone losing their hearing or sight. They still think the same way they just don't have as much input to use to think with.
Thus the correct way to think about a head in a jar is as a severely handicapped individual. And no doubt the personality of that brain would change over time. (But that's true of all brains.)
Since you said head in a jar I assume you mean that the eyes, ears, nose, mouth are still intact and functioning. If not, then we have the absense of these inputs, but the brain would still function the same way. But it would have no input to operate on. Sensory deprivation studies have shown that brains will create their own inputs, aka hallucinations. The person associated with that brain, experiencing massive sensory loss would probably go insane.
Steve M
Probably in a few years scientists will find that intestinal cilia are used as well...
That's why so many people have shit for brains.
If your brain is, indeed, a muscle, it's easily understandable how you might be unable to pat and rub your belly at the same time.
Fire and Meat. Yummy.
The experiment involved artificially increasing levels of calcium in astrocytes (a type of glial cell) while monitoring adjacent neurons for signs of response to released neurotransmitters. Since the levels of calcium required were comparable to those found in the natural environment, the researchers concluded that glial cells may control neurotransmitter balance in the brain as well. I'd like to know if there's evidence that glial cells also have functional calcium uptake pumps, and if their level of calcium fluctuates with blood level or remains constant. Unfortunately, reading the full article requires a paid subscription...
While this is interesting news, it's certainly not true that we ever thought of glia as (in the words of the press release) "little more than glue." Glial cells produce the myelin sheathing that allows motor signals to travel rapidly from the brain to the extremities, and their signals are important to laying down the organization of different areas in the early months of brain development. They're also an important adversary when it comes to repairing nerve damage in the periphery. Severed nerves actually try to grow back along their established pathways, but the glial cells poison them (presumably to prevent inappropriate overgrowth). Learning to inhibit this process may be the key to restoring limbs that are paralyzed.
- Michael Cohn
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Else we'd put legs on our automobiles and
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The Win Wenger/Project Renaisance page is actually *not* hosted by slashdot, but is at http://www.winwenger.com/.. Win Wenger's written 48 books, many on the nature of intelligence. I've only read The Einstein Factor, but found it very interesting. Based on his 35 years of research, he claims that anyone can raise their I.Q. by 20 points in 25 hours.. If it worked for Einstein, it can work for me, right? Anakin's Brain has the full text of two of his books in the Project Renaisance section..
Learn the rules so you know how to break them properly.
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Uhh no, it's Neurons, I don't know where you learned to spell it.
That is, they also metabolize/"mop-up" chemicals released by neurotransmitters. This is a general application of "Garbage Collection" in the technical sense; by re-allocating disused resources the GCs are doing hardware-based GC for the brain.
I thought this looked familiar.
Murphy TH; Blatter LA; Wier WG; Baraban JM.
Rapid communication between neurons and astrocytes in primary cortical cultures.
Journal of Neuroscience, 1993 Jun, 13(6):2672-9.
And in related news...
See that "Preview" button?
Or, as Francis Crick puts it, the body is the mind. Any mind/body duality is more religious hocus-pocus than actual fact. Do you think that a head in a jar would think in the same was as when it was attached to the rest of the body?
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