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'Giant' Neuron Regulates 50,000 Other Neurons

Soulskill posted more than 3 years ago | from the intercranial-superdelegate dept.

Science 81

Scottingham sends this quote from PhysOrg: "A single interneuron controls activity adaptively in 50,000 neurons, enabling consistently sparse codes for odors (abstract). The brain is a coding machine: it translates physical inputs from the world into visual, olfactory, auditory, tactile perceptions via the mysterious language of its nerve cells and the networks which they form. Neural codes could in principle take many forms, but in regions forming bottlenecks for information flow (e.g., the optic nerve) or in areas important for memory, sparse codes are highly desirable. ... This single giant interneuron tracks in real time the activity of several tens of thousands of neurons in an olfactory centre and feeds inhibition back onto all of them, so as to maintain their collective output within an appropriately sparse regime. In this way, representation sparseness remains steady as input intensity or complexity varies."

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My dog (2)

inode_buddha (576844) | more than 3 years ago | (#36122000)

... he might know a thing or two about this...

Re:My dog (1)

Sene (1794986) | more than 3 years ago | (#36122878)

Maybe he should write to /.? Let me know if he has some input to this article.

Re:My dog (2)

EdIII (1114411) | more than 3 years ago | (#36129370)

Funny you mention dogs, when I am pretty damn sure that on some occasions that your dog farted that the "input intensity" was so high that "representation sparseness" is not as steady as one might think.

Single Point of Failure? (1)

Anonymous Coward | more than 3 years ago | (#36122006)

What happens if this single neuron fails/is damaged?

Viruses and sense of smell (0)

Anonymous Coward | more than 3 years ago | (#36122040)

I wonder if this is related to the loss of taste/smell for a few months after you get certain viruses.

Re:Single Point of Failure? (1)

Repossessed (1117929) | more than 3 years ago | (#36122188)

Ignoring the bit where this isn't human neurology (great summary there), iirc the olfactory neurons are the only ones that can actually grow back.

Re:Single Point of Failure? (1)

interkin3tic (1469267) | more than 3 years ago | (#36122348)

What happens if this single neuron fails/is damaged?

I'd hazard a guess: that it sucks for the individual locust, but evolution doesn't serve the individual locust, it serves the species. The species with a simpler designed system, with that single point of failure, maybe it gets individuals that mature faster and breed faster than one with redundancies, and thus is the design that wins.

Simplicity, not complexity, is the direction evolution usually favors. We, as an unsuccessful, complex dead end of evolution (from an evolution standpoint) tend to think of complexity as the better of the two directions in evolution, but we're vastly outnumbered by species that are simpler than us. Good for us as individuals, but our numbers take -much- longer to grow. We have two eyes, and that's good for us, but if there had been a branch of cavemen with one eye, but they only took 8 months of development instead of 9, we might have been cyclopses.

(I am not an evolutionary biologist, so this might be completely outdated theory by now)

Re:Single Point of Failure? (4, Interesting)

Mindcontrolled (1388007) | more than 3 years ago | (#36122730)

Hm. From what I remember regarding current theory - and that is a decade ago - complexity is not even the question. I wouldn't outright qualify us as overcomplex deadend. You have to envision the whole process as a massively dynamic system. There is no best, there is no dead end - there is only temporary optimization towards local optima in the fitness landscape. At the moment, we seem to pretty much PWN one of those local optima, while at the same time eroding the boundary conditions that makes it optimal...

Re:Single Point of Failure? (4, Insightful)

Luckyo (1726890) | more than 3 years ago | (#36122832)

It's worth noting that this is still considered largely correct. The most successful life form on the planet is a fly, and most successful mammal is a rat.

A great example of minimalism working in favor of evolution in humans is our intestinal tract. If you look at most large apes that bear close resemblance to humans, they can eat food that would cause us to get sick and die, in spite of being similar omnivores to us humans. Why? Because at the end of our evolution, we discovered fire. Cooking causes most proteins to break up as well as largely disinfect the food. Adapting to this, the humans who survived the evolutionary selection were the ones who had vastly downsized and simplified intestinal tract, that couldn't consume much of the uncooked food that larger could. This means that where apes and some other prehistoric evolutionary branches of human race ate raw food, and had to use much more energy digesting it, in turn causing it to need more food for same amount of work, humans who survived were far more efficient. This is very noticeable when you look at gorillas for example - they have large pot bellies, mainly because of sheer size of their intestinal tract.

In this regard, if humans were to lose knowledge of fire, they would likely become extinct, as our ability to eat uncooked food is severely hamstrung by our evolution. But as long as we can cook, we are far more energy efficient then competition. As a result, we can afford a much larger brain, that consumes much more energy. A very common argument in modern evolutionary theory is that discovery of fire, and consequent evolution of our intestinal tract have been a requirement for evolution into modern homo sapiens, as without it, we would be unlikely to be able to successfully support our current brain's energy needs.

In this regard, the requirement for two eyes is actually not about conservation - it's about need for stereo vision for successful hunting. The proper argument is that we don't have a third eye in case of loss of one eye (and subsequent severe diminishing of ability to hunt) because of minimalism - those who lose an eye will likely die off but majority will be able to die of other reasons.

Re:Single Point of Failure? (1)

Broolucks (1978922) | more than 3 years ago | (#36122996)

What does "successful" mean, though? Greater numbers? Resilience to environmental changes? I don't think "successful" is a particularly meaningful term - in an evolutionary sense, any species is successful as long as it does not go extinct, which makes all current species successful. Great numbers, large geographical extent, being at the top of the food chain, potential to survive catastrophic events could all be interpreted as "success", but depending on which you value more, you will rank species differently. I don't see any objective reason to consider that rats, as a species, are any more or less successful than we are.

Re:Single Point of Failure? (1)

interkin3tic (1469267) | more than 3 years ago | (#36123742)

What does "successful" mean, though?

Successful is probably not the word I should have used. "Fitness" is the more common term than success, at least in my experience (probably since success has different connotations.)

And this page [rcn.com] concisely defines it:

Fitness is a measure of reproductive success. Those individuals who leave the largest number of mature offspring are the fittest. This can be achieved in several ways: Survival or mortality selection Mating success or sexual selection Family size or fecundity selection

From an evolutionary standpoint, rats are most certainly more fit than we are: they reproduce far more often, have far more offspring.

Re:Single Point of Failure? (1)

Broolucks (1978922) | more than 3 years ago | (#36124056)

Fitness is an individual measure, though. Individuals are fit, not species, and it does not seem fair to compare a member of one species to a member of another species in terms of fitness. A rat which produces less mature offspring than most other rats could be said to be unfit (its genes will fail to spread), whereas a human who has more children than the average human will be deemed fit (their genes will spread faster), due to their respective competition. The "unfit" rat might be "fitter" than the "fit" human, but is that meaningful? They have very different lifespans, very different sizes and do not play in the same reproductive pool anyway. Apples and oranges.

Species as a whole could be said to be fitter in proportion of the total number of mature offspring a generation produces, but this is heavily and unequivocally slanted to the benefit of smaller organisms. It might be the correct definition of "fit", but I do not find it very meaningful or useful - obviously the same amount of resources can support more small organisms than big ones. Thus the count should at least be scaled by biomass (rats might still win, but at least the comparison is more fair).

As far as *species* go, to me, it makes more sense to define its "fitness" as its ability to spread its collective genes on a macroscopic time scale: a species is "fit" in proportion of the percentage of the biomass that runs on genes derived from the species (including members of the species itself). Thus the "first mammal species" (does that make sense?) was much fitter than all of its contemporaries that died without trace, because it had many more "offspring" (sub-species in this case). Under that definition, of course, it's rather difficult to evaluate fitness of contemporary species...

Re:Single Point of Failure? (1)

interkin3tic (1469267) | more than 3 years ago | (#36123706)

The most successful life form on the planet is a fly

Pretty sure that title would go to bacteria, who outnumber flies by orders of magnitude, much as flies outnumber us by orders of magnitude.

Re:Single Point of Failure? (1)

TheLink (130905) | more than 3 years ago | (#36124092)

I've asked a Buddhist friend whether viruses are the highest lifeform before nirvana instead of humans (there seems to be a popular assumption that humans are one of the higher ones).

After all it seems likely that viruses have reduced amounts of craving and have pretty much minimal delusion: http://en.wikipedia.org/wiki/Buddhism#Suffering.27s_causes_and_solution [wikipedia.org]

There are more viruses, so maybe that's good news - more and more entities are close to Nirvana ;).

Re:Single Point of Failure? (1)

Ungrounded Lightning (62228) | more than 3 years ago | (#36124670)

A great example of minimalism working in favor of evolution in humans is our intestinal tract. ... at the end of our evolution, we discovered fire. Cooking causes most proteins to break up as well as largely disinfect the food

Actually our got 'way more complex to handle the toxins from cooking and living in smoke-filled areas. (For starters, some of the dioxins are moderate carcinogens for people and kills nearly any other animal - to the point of causing birds who fly through a plume of it to fall from the sky dead.)

What fire predigestion did is let us get away with a SMALLER digestive tract, not necessarily a SIMPLER one. Less mass to carry around, smaller equipment to build and maintain at cost in energy and material.

Re:Single Point of Failure? (1)

Luckyo (1726890) | more than 3 years ago | (#36126510)

While true, many omnivorous mammals such as apes can consume cooked food without major problems. We on the other hand cannot consume raw meat or unwashed vegetarian menu because our digestive system isn't designed for it and will get hit by major diseases and various problems.
A good comparison here is any large predator such as wolf. It can consume raw meat, in state of significant decay. It's stomach will destroy most of the bacteria and small parasites and intestines will be able to absorb nutrients from such a diet. We would not.

Our intestinal tract is MUCH simpler in this regard then almost any omnivorous mammal of similar size, in addition to being smaller.

Notably, carcinogenic effect of the smoke is not negated by our digestive system to a degree so significant that would clearly differ from other similar mammals such as apes. Note that much of the cooking does NOT involve smoke - there is significant proof that much of diet was in fact in form of various stews rather then smoked meat, as stews offer a significantly better nutritional value due to better absorption. Finally, carcinogenic effects are very long-term, and average life span of a human in stone age was well below 20, meaning individuals chance to die of cancer while of breeding age was nonexistent.

Re:Single Point of Failure? (2)

lobiusmoop (305328) | more than 3 years ago | (#36123004)

Epilepsy? I believe seizures are essentially the failure of neural suppression and the brain consequently lighting up like a Christmas tree, maybe has something to do with this.

So the brain has supernodes? (1)

rsborg (111459) | more than 3 years ago | (#36122018)

I wonder how much more similar P2P networks/algorithms are when compared to wetware neural networks like the brain...

Re:So the brain has supernodes? (1)

blair1q (305137) | more than 3 years ago | (#36122102)

p2p is a square wheel compared to a handful of neurons.

Re:So the brain has supernodes? (-1)

Anonymous Coward | more than 3 years ago | (#36122958)

You mean a brain, idiot.

A "handful of neurons" is nothing without the proper architecture. In any case, what do you think you accomplish with that comment?

Did you get offended because your neural network got compared to a P2P network?

Re:So the brain has supernodes? (0)

blair1q (305137) | more than 3 years ago | (#36123194)

No, I mean a handful of neurons, dumbfuck.

The total computing power of a P2P network is overwhelmed by the subtle complexity of a small neural network.

Did you get dropped on the head as a child, enjoy it, and continue to do it?

Re:So the brain has supernodes? (4, Insightful)

GuldKalle (1065310) | more than 3 years ago | (#36122164)

One more commonality: The media industry hates when you use it.

Re:So the brain has supernodes? (1)

ackthpt (218170) | more than 3 years ago | (#36122382)

One more commonality: The media industry hates when you use it.

Add to that...
 

  • Oil
  • Technology
  • Transportation
  • People of extreme political views
  • Terrorist leaders...

"Uh, excuse me, but if I'll be waited on by a McJillian virgins and it's all so wonderful, why haven't you strapped a bomb on under your coat and walked into a crowd?"

Re:So the brain has supernodes? (1)

Hatta (162192) | more than 3 years ago | (#36122534)

Probably pretty similar. Scale free networks (the kind with super nodes) are incredibly common in nature. It would be a lot more surprising if they found that there weren't super node neurons.

Re:So the brain has supernodes? (0)

Anonymous Coward | more than 3 years ago | (#36123276)

The computer analogy would be digitizing analog inputs, or encoding such as how we represent many possible characters with fonts and codepoints instead of tracking every character as a collection of pixels or strokes.

Blind Chance (1)

Anonymous Coward | more than 3 years ago | (#36122026)

This obviously the work of blind chance and natural forces operating over time. And we make fun by invoking the FSM...

Re:Blind Chance (1)

cyber-vandal (148830) | more than 3 years ago | (#36122894)

It's not blind chance, it's mutations that provide an advantage being passed on to offspring. Now stop trolling Slashdot and go find some actual evidence for ID if it bothers you that much.

summary (0)

Anonymous Coward | more than 3 years ago | (#36122050)

This summary is really confusing. Someone should write an article about something like this. I would read it.

Re:summary (1)

blair1q (305137) | more than 3 years ago | (#36122112)

Actually, it's a darned good summary. But then, I have some prior knowledge of this stuff. You might want to read a book or two on neurology and real (not artificial) neural networks.

So.... traffic throttling in my brain? (2)

chemicaldave (1776600) | more than 3 years ago | (#36122072)

My ISP already wants to do this.

This single giant interneuron tracks in real time the activity of several tens of thousands of neurons in an olfactory centre and feeds inhibition back onto all of them, so as to maintain their collective output within an appropriately sparse regime.

Re:So.... traffic throttling in my brain? (0)

Anonymous Coward | more than 3 years ago | (#36122108)

My ISP already wants to do this.

Can this be used as prior art to invalidate some patents?

Re:So.... traffic throttling in my brain? (2)

steelfood (895457) | more than 3 years ago | (#36122638)

It's QoS. If you were being attacked, you probably wouldn't want to be concerned with what your attacker smelled like.

in brain of locusts (4, Informative)

N1ck0 (803359) | more than 3 years ago | (#36122082)

Key part of the article that is not in the small summary...

Scientists at the Max Planck Institute for Brain Research in Frankfurt have now discovered a single neuron in the brain of locusts that enables the adaptive regulation of sparseness in olfactory codes

Re:in brain of locusts (1)

ackthpt (218170) | more than 3 years ago | (#36122346)

Key part of the article that is not in the small summary...

Scientists at the Max Planck Institute for Brain Research in Frankfurt have now discovered a single neuron in the brain of locusts that enables the adaptive regulation of sparseness in olfactory codes

So ... this explains last night's American Idol voting...

something had to...

Re:in brain of locusts (1)

rubycodez (864176) | more than 3 years ago | (#36122484)

might also explain why hoards of people can stand to watch it?

Re:in brain of locusts (2)

rubycodez (864176) | more than 3 years ago | (#36122476)

oh yeah??? well, I have just three things to say to you, smarty-pants: Bzzzzzzzzzzzzzzzzzzzz!, Bzzzzzzzzzzzzzzz!, BZZZZZZZZZZZZZZZZZZZZZZZZ!

Re:in brain of locusts (2)

Mindcontrolled (1388007) | more than 3 years ago | (#36122752)

Well, yeah, but evolution kinda operates under a object oriented paradigma. Code reusability is the new big thing since a couple of 100s of millions of years... So this is still interesting.

Re:in brain of locusts (0)

Anonymous Coward | more than 3 years ago | (#36123350)

I have no idea who told you, that code reusability would have anything to do with object orientation...

The function is the core of reusability. Variables/identifiers are its main tool. That primitive languages (C/C++/Java/Python/Perl/Ruby/JS/etc.) have such large functions that reuse becomes a problem is really just their problem.
In Haskell, functions often only have one line. E.g. for loops are separated out (map function, and its generalization fold*), you can pass around functions (higher order functions), use operators to make functions out of functions (combinators), and can even re-program the "semicolon" (monads).

Object oriented programming is good, when it is useful for what you want to do. But it is pretty limited. And it definitely is not the mother of code reusability.
(Oh, and class/prototype hierarchy trees are a huge failure, since in the real world, things aren't trees but graphs.)

Focus (1)

blair1q (305137) | more than 3 years ago | (#36122086)

Dominance of one input over the others and focus at the expense of seeing the overall picture.

It's the tunnel-vision neuron. And it's intentional.

Fascinating.

Re:Focus (1)

peragrin (659227) | more than 3 years ago | (#36122156)

and it is found in locusts. the whole swarm/herd mentality suddenly makes sense.

Re:Focus (1)

ackthpt (218170) | more than 3 years ago | (#36122252)

Dominance of one input over the others and focus at the expense of seeing the overall picture.

It's the tunnel-vision neuron. And it's intentional.

Fascinating.

Sounds like at least a dozen Talk Radio and TV Talk Show hosts.

"What does bloated master neuron say now?"
"It say subscribe to its political action newsletter!"

We're gonna be mentats! (1)

Dutchmaan (442553) | more than 3 years ago | (#36122092)

The more I read about the brain the more I see a future where we're tailoring "specialized" people who might process specific types of information with vast superiority while debilitating themselves in other areas. I could see area's where say an engineer would have highly developed logical/mathmatical ability while maybe gimping himself in auditory processing or something. Which actually seems something like self induced autism.

Re:We're gonna be mentats! (2)

fritsd (924429) | more than 3 years ago | (#36122360)

Yes, you seem to be looking at a brave new world ...

Re:We're gonna be mentats! (1)

Thing 1 (178996) | more than 3 years ago | (#36124320)

The more I read about the brain the more I see a future where we're tailoring "specialized" people who might process specific types of information with vast superiority while debilitating themselves in other areas. I could see area's where say an engineer would have highly developed logical/mathmatical ability while maybe gimping himself in auditory processing or something. Which actually seems something like self induced autism.

Well, I use noise-cancelling headphones. So: am I "self-inducing autism" because I want to keep the inane chatter out, in order to focus and be productive? I guess so: I've been doing it for many years, and I have close to zero social life. But my Ferrari and houses are paid off. Autism FTW! (Well, it feels more like Asperger's...)

Re:We're gonna be mentats! (0)

Anonymous Coward | more than 3 years ago | (#36125362)

Republicans are already doing this: shutting down the reasoning centers and instead mastering the art of bullshit.

Re:We're gonna be mentats! (0)

Anonymous Coward | more than 3 years ago | (#36126130)

Not if you could switch between these modes at will - that would be kind of awesome.

Re:We're gonna be mentats! (1)

Kyont (145761) | more than 3 years ago | (#36137230)

Without engineering this, we'll be evolving towards this based on the college admissions process anyway. It used to be that universities wanted well-rounded people who could take their education and integrate their knowledge into society afterwards. Nowadays, the competitive places want their freshmen to be the best in the world in one narrow area, with little thought given to how they'll function as adults.

Maybe the increased incidence of autism/Asperger's these days is actually... the beginnings of an evolutionary response to this pressure? Nah, too fast...

This could be fun. (1)

jd (1658) | more than 3 years ago | (#36122120)

GENESIS [genesis-sim.org] is a neural net that simulates biological neural networks rather than comp-sci ones. It is also so horribly complex that they've rebuilt it from the ground up three times. If they now have to handle supernodes, active queue management and load balancing, they'll be on version 4 before 3 even gets past the alpha releases. This is not an insignificant change.

only important question left in neuropsychiatry (1)

eyenot (102141) | more than 3 years ago | (#36122150)

does this explain telepathy, yet?

Re:only important question left in neuropsychiatry (1)

FiloEleven (602040) | more than 3 years ago | (#36124942)

If you're interested in a scientific framework that actually incorporates the thousands of examples of supernormal phenomena (including things like telepathy, near death and out-of-body experiences, genius and creativity, veridical apparitions and the like), I suggest taking a look at the book Irreducible Mind: Toward a Psychology for the 21st Century [google.com] . A fellow slashdotter turned me on to the book and I've been impressed by the scientific way in which they have both presented and synthesized the evidence for the existence of self apart from brain activity. If you were being facetious, ignore the rest of this post because it's pretty much a book review.

The gist of the presented theory as I understand it is a kind of dualism--a dirty word, I know--that unlike classical dualism posits the material and non-material realms as being very intertwined. It has its roots in the classical psychological theories of Myers, James and others, and I've found it to be very intriguing so far (I'm about 2/3 of the way through). I have read other books on the subject but most of them (even the ones I like) suffer from untrustworthy authors pushing some kind of new-age agenda. These authors, in contrast, are building their case on sound reasoning and evaluation of evidence that tends to be summarily dismissed from mainstream discourse simply because it doesn't fit the prevailing theory. I speak here of a large volume evidence gathered by practicing psychologists, not anecdotes from your stoned uncle. In fact, nearly the last hundred pages of the book (!) are an appendix of case studies containing supporting evidence. Cases taken in isolation are merely interesting (and the authors are quick to point out any weaknesses found in them), but when taken en masse are quite compelling. What the authors are asking for is not acceptance of their theory; they are instead asking for the scientific community to really consider the existing body of evidence and to do further experiments based on it. Much like the creator of the theory, they recognize that further study is sorely needed before anything conclusive can be drawn. Those experiments will either lend weight to their theory or will point in a different direction--either way, we've expanded our scientific knowledge.

A slightly more detailed description of Myers' theory (upon which this book builds) is that consciousness (and the brain) acts as a filter, adapted by evolution for survival in the physical world. The authors use the analogy of the electromagnetic spectrum: if the whole range of mind is the entire spectrum, then everyday consciousness represents the visual portion. At the "infrared" boundary we have things like control of the heartbeat, allergies, body temperature, and other low-level body operations that can with practice be influenced by the mind, sometimes spectacularly. At the "ultraviolet" end lie things like genius, creativity, and the whole range of "paranormal" phenomena. (This metaphor has interesting ties to Hindu mysticism that AFAIK are not mentioned by the authors.) The reason we don't see a lot of it is because it has not been useful from an evolutionary perspective. Some psychological disorders such as Multiple Personality Disorder are according to this theory pathological manifestations of things which lie (metaphorically again) towards the high end of the spectrum.

The use of hypnosis is responsible for accessing a lot of this stuff, and that it is routinely brushed aside as "merely suggestion" is a great failing of contemporary psychologists. Saying that an allergy can be removed or triggered by suggestion leads one to believe that the mechanism by which local skin cells can be agitated or inhibited by thought or will is both understood and not worth investigating further. Hypnosis may very well be the best investigative tool we have for getting at the heart of the mind-body problem. And they specifically warn against using random college students as subjects. It is by studying the exceptional--those who are highly susceptible to hypnosis or have a reported history of exhibiting psychic phenomena--that the nature of the ordinary is made clearer. Quantum physics would not be at the refined state it is today if we looked at slow-moving water particles instead of smashing exotic atoms in massive machines. Questions concerning experimental integrity are handled in depth on numerous occasions.

I only wish the book was more widely available at libraries. It's a little expensive for the armchair skeptic to invest in (I paid $35 for my softcover copy), which is why I linked the Google Books search that allows a preview. I am not yet convinced that their proposed theory is on the right track (I myself lean more towards some form of monism), but I am quite certain that consciousness and its relation to the brain is far less understood than neuroscientists currently believe it to be. This is a genuine piece of scientific study that is worth looking at by anyone who is interested in consciousness which in my opinion rivals Hofstadter's Gödel Escher Bach in importance, though the latter of course remains unmatched in execution.

-f

Re:only important question left in neuropsychiatry (1)

St.Creed (853824) | more than 3 years ago | (#36127958)

While I disagree with the premise of your post, I do think it is a shame the whole "placebo effect" is not understood in more detail. If we could reliably trigger the placebo effect in everyone, it would certainly do a lot to help us control our bodies and ultimately, our lives.

Re:only important question left in neuropsychiatry (1)

FiloEleven (602040) | more than 3 years ago | (#36128456)

Oh, I agree completely! Placebo is another one of those things (like suggestion) that has been labeled and then brushed aside because it is a difficult problem to tackle. Its position in science is interesting because it is universally acknowledged to exist, but the fact that it represents a huge gap in our knowledge of how our minds and bodies interact is just as universally ignored.

Its greatest efficacy is in pain management, which is subjective and can be hard to test, but it also has applications in things like allergic reactions that are unexplained (and probably unexplainable) by prevailing theories. Nobody's looking at the mechanism by which someone can cause a localized allergic reaction in their left forearm and not their right when the only difference between the two substances that touched them is that they were told one is an allergen. This has been shown to work equally well when an inert substance is used and when an allergenic substance is used. The really interesting thing about this is that unlike pain management, there is nothing anywhere in the brain or nervous system to regulate histamine response--it is a local phenomenon.

The tricky part in experimenting with placebo is to find the right subjects, as not all people are equally susceptible to placebo effects. As I wrote above, the mistake being made is to take a random sample of people when what we ought to be doing is to find individuals who show drastic effects--this would make for a more reliable means of studying the phenomenon. (Of course this should not be done for medicinal trials because the goals are completely different.) Control groups, people with an average amount of susceptibility, would be necessary too, but it ought to be an explicit variable in the experiment.

Anecdotally, it seems to me that more and more people I talk to in life and online are getting interested in the placebo effect, so maybe within the next decade we'll see some good research coming out.

My question to you is this: what if reliably triggering the placebo effect takes the form of hypnosis or visualization, basically having someone else or yourself deeply convince you that you have no pain or warts or allergies or whatever? It seems pretty clear even at this early stage that it's a case of "mind over matter," that is, the patient must believe that the desired effects will occur, and there are a whole lot of factors involved: how much the patient trusts the doctor, the diagnosis, the pill...none of which can be relied upon. Would you be willing to undergo hypnosis, or put effort into meditation-like visualization techniques? I guess what I mean is, how do you reconcile the way in which the placebo effect almost conclusively has to work with an apparent skepticism about the mind's capabilities to affect (at the very least) its body?

Nice summary ...not! (5, Insightful)

spikenerd (642677) | more than 3 years ago | (#36122152)

Since the summary is somewhat ...lacking, here's my attempt to translate it. (Disclaimer: I am not a neuroscientist, and I really only skimmed it anyway.)

"We studied the olfactory system of locusts, and found that all of the smell information seems to pass through a single neuron with a lot of incoming connections. This single neuron does not send outgoing signals in spikes as most other neurons do, but instead releases a chemical that suppresses other neurons. It uses this method to sort-of "average" all of the incoming signals together. Also, this system involves a feedback loop. We think that this whole arrangement is set up to generate sparse-codes, which is our favorite way to reduce information down to a small number of dimensional values. We hope that mammals use similar systems, and that this might eventually help lead to an understanding of how brains reduce large amounts of information into small concepts."

Re:Nice summary ...not! (0)

Anonymous Coward | more than 3 years ago | (#36122444)

I AM a neuroscientist, and familiar with this work. Your summary is pretty accurate. The only things I would add is that mammals do indeed use similar systems. i.e. they also have sparse codes for odour identity and use inhibition to achieve this. What don't have, however, is an analogue of this particular neuron. What is interesting is that mammals and and insects produce the same olfactory codes even though there are differences in how the brain achieves this.

Re:Nice summary ...not! (1)

taiwanjohn (103839) | more than 3 years ago | (#36127782)

> mammals and and insects produce the same olfactory codes even though there are differences in how the brain achieves this.

How do we "know" that the codes are the same? I don't doubt what you say, I'm just curious.

Re:Nice summary ...not! (0)

Anonymous Coward | more than 3 years ago | (#36123128)

Interesting to see how this work matches Hawkin's formulation of how the mind works. Here [youtube.com] is a presentation where he talks about his ideas on some of the issues trying to understand how the human neural network functions.

Re:Nice summary ...not! (0)

Anonymous Coward | more than 3 years ago | (#36124178)

Is there a summary of his claims/ideas? Basically I want to skip the "50,000 words in the video" and get to the actual ideas/claims?

Re:Nice summary ...not! (0)

Anonymous Coward | more than 3 years ago | (#36124780)

You should apply for a /. editor job.

In the fly... (1)

SiMac (409541) | more than 3 years ago | (#36122168)

For many reasons, there is almost certainly nothing like this in the mammalian brain.

Sorry, they are locusts (1)

SiMac (409541) | more than 3 years ago | (#36122184)

But the comment still stands.

Re:Sorry, they are locusts (1)

Seekerofknowledge (134616) | more than 3 years ago | (#36122418)

What are the reasons?

Something interesting from the article:

"The giant interneuron and the Kenyon cells form a simple negative feed-back loop: the more strongly it is activated by the Kenyon cell population, the more strongly it curtails their activity in return", explains Laurent. The interneuron itself does not generate any action potentials, but inhibits Kenyon cells via nonspiking and graded release of the neurotransmitter GABA (gamma aminobutyric acid).

There is a negative feedback loop. I wonder if this could lead to side-effects like our lowered sensitivity to a smell over time. Some say the smell is just not registering in our conscious, I wonder if the smell is not even registering on the olfactory nerves at all.

Re:In the fly... (3, Informative)

interkin3tic (1469267) | more than 3 years ago | (#36122614)

Wrong. Invertebrate model organisms are how most discoveries about the mammalian brain started off and continue to be how we discover the basics. On the most obvious level, THIS IS A NEURON. Same type of cell your brain is made up of.

As far as one individual meganeuron in your head, maybe not. I think the histologists of the past would have realized if there were giant neurons similar to this. In the 1800's, they were using advanced staining techniques to show the shape of cells, I think if one neuron were synapsing with that many neurons, it would have shown up with golgi staining back then, or with the brainbow mouse [scienceblogs.com] more recently.

The concept of bottlenecking information when sparsity is necessary: that probably IS a valuable lesson for human brains. It probably isn't a single cell, but the concept is still possible with a smaller number of cells.

Anyway, as a general rule, it's idiotic to write off any valid scientific findings as "not interesting" just because they don't immediately beat you over the head with the relevance.

Re:In the fly... (0)

Anonymous Coward | more than 3 years ago | (#36123164)

The homunculus theory finally validated

Re:In the fly... (1)

SiMac (409541) | more than 3 years ago | (#36125344)

Wrong. Invertebrate model organisms are how most discoveries about the mammalian brain started off and continue to be how we discover the basics. On the most obvious level, THIS IS A NEURON. Same type of cell your brain is made up of.

Most of the important early discoveries in the invertebrate nervous system that were shown to hold in the mammalian brain had to do with the dynamics of individual neurons, not systems. The important discovery here is at the system level, not the single neuron level. While quite a few people would disagree, I couldn't care less about the dynamics of the insect olfactory bulb if they do not translate to the primate brain.

As far as one individual meganeuron in your head, maybe not. I think the histologists of the past would have realized if there were giant neurons similar to this. In the 1800's, they were using advanced staining techniques to show the shape of cells, I think if one neuron were synapsing with that many neurons, it would have shown up with golgi staining back then, or with the brainbow mouse [scienceblogs.com] more recently.

The average neuron in cerebral cortex makes on the order of 10,000 synapses. I would not be surprised if you can find neurons that make more than 50,000, particularly in small regions with a large number of long-range projections (e.g., VTA and striatum). I would be surprised if anything goes wrong if you kill a single one, which was my point. I'd also be very surprised if they don't fire action potentials.

FWIW, tracing the full extent of the synaptic connections of a single neuron in a mammalian brain is hard with any of these techniques, because you are typically labeling a large number of cells and trying to trace them through a large number of slices. Ed Callaway has a solution for labeling all presynaptic neurons targeting a single neuron [sciencedirect.com] , but I'm not aware of any good solutions for targeting postsynaptic cells.

The concept of bottlenecking information when sparsity is necessary: that probably IS a valuable lesson for human brains. It probably isn't a single cell, but the concept is still possible with a smaller number of cells.

This is possible, but I would say "maybe" and not "probably." There are computational principles that seem to apply in some brains but not others. (For example, intracellular recordings suggest that sequential firing during singing in songbird HVC is probably generated by synfire chains [nature.com] whereas sequential firing in the hippocampus during navigation likely has a more complex basis [nature.com] .) It's possible this principle holds in the mammalian olfactory bulb, although I would think a relatively large population of neurons would be involved. But, I would be surprised if it holds in neocortex. Most neocortical neurons are not all that sparse in comparison to neurons in archicortex, and connectivity patterns in neocortex are vastly different. The point is, we really don't know how sparseness is achieved in our own brains, and this article doesn't really add much on its own, although it suggests a path for further investigation. Since the article summary conveniently ignores the fact that this work was performed in an insect model, it makes it appear as if this strategy is used throughout the human brain, when this is very far from established.

Re:In the fly... (0)

Anonymous Coward | more than 3 years ago | (#36126934)

You have to remember that unlike the songbird system vs the hippocampus, the vertebrate and invertebrate olfactory systems share many many other things in common.

Olfactory receptor neurons each express 1 receptor, and all the neurons that express the receptor project to the same 2nd order region, where the odor representation is transformed into the synchronized spiking of second order neurons. This is conveyed to the third order center, where a larger population of third order neurons represent odors sparesly, even when the strength of the input changes with odor concentration.

Now, all that applies to vertebrates and invertebrates. This paper answers the question, in invertebrates, of how sparse spiking is maintained in the face of changes in input strength. Something along these lines HAS to be present in vertebrate systems, given the experimental results that they, like invertebrates, maintain sparse odor representations.

But even if there were not so, so many things in common between vertebrate and invertebrate olfaction, I think that it is a mistake to not pay attention to the invertebrate work. There is no way we are going to understand the primate brain until we understand the locust brain.

Re:In the fly... (0)

Anonymous Coward | more than 3 years ago | (#36127094)

The average neuron in cerebral cortex makes on the order of 10,000 synapses. I would not be surprised if you can find neurons that make more than 50,000, particularly in small regions with a large number of long-range projections (e.g., VTA and striatum).

Right. e.g., Purkinje cells (found in cerebellum) can have >200,000 synaptic inputs.

Probably holds a patent... (1)

ackthpt (218170) | more than 3 years ago | (#36122204)

In Soviet Russian Giant Neuron regulates YOU!

Inhibition? (0)

Anonymous Coward | more than 3 years ago | (#36122248)

You mean if I clobber a few interneurons I'll have better luck with the ladies?

Re:Inhibition? (1)

snspdaarf (1314399) | more than 3 years ago | (#36122316)

You mean if I clobber a few interneurons I'll have better luck with the ladies?

Why do you think men try to get them drunk?

I for one... (0)

Anonymous Coward | more than 3 years ago | (#36122326)

I for one welcome our--oooh somebody's barbequing somewhere.

Let me be the first to say it... (1)

frank_adrian314159 (469671) | more than 3 years ago | (#36122334)

This research stinks!

Gaint Neuron rises out of Fukishiama (1)

fregare (923563) | more than 3 years ago | (#36122408)

In news today: The Giant NEURON arose from the seas outside Fukishiama the successor to Godzilla.

That's not 'coding' (1)

fractalspace (1241106) | more than 3 years ago | (#36122500)

That's not coding. That's just conversion (or parsing).

Inhibition? The AI Mind uses inhibition, too! (0)

Anonymous Coward | more than 3 years ago | (#36122784)

Even the AI Mind in JavaScript [scn.org] uses inhibition [scholarpedia.org] for electronic brain function, not for enforcing a sparse olfacotry environment, but rather to suppress just-past thoughts in favor of yet-to-emerge thoughts.

Squelching? (0)

Anonymous Coward | more than 3 years ago | (#36123818)

Would that be qualified as a kind of squelching (from radio communications)?

Right. Okay. (1)

Jane Q. Public (1010737) | more than 3 years ago | (#36125074)

So the brain has volume controls. So what? Makes sense to me.

(But I have to throw in: for humans anyway, the optical nerve is a "bottleneck" about like a TB network connection is in a typical office. If that's a "bottleneck", give me more.)

Re:Right. Okay. (1)

Jane Q. Public (1010737) | more than 3 years ago | (#36125090)

But I will admit that it is a "bottleneck" in that much information must flow over a small conduit. That much is true. It's just that the word "bottleneck", these days, has come to imply a place where information slows or gets stuck. I don't think that is what is meant by "bottleneck" here.

This is the mechanism used by Brain Slugs (1)

TechnoInfidel (569458) | more than 3 years ago | (#36125654)

Which reminds me, we should all visit the Brain Slug planet, and wander about without helmets.

interesting (1)

StuffMaster (412029) | more than 3 years ago | (#36128754)

This sort of makes sense to me....a million flowers won't overload your nose and partially incapacitate you, but a giant spotlight on your eyes or a jumbo jet next to your ear will.

Re:interesting (1)

bennettp (1014215) | more than 3 years ago | (#36141650)

True, but there might be disadvantages to tolerance of overexposure to sights and sounds. A jumbo jet will probably damage your hearing. A giant spotlight might not damage your sight, but the sun will, eventually. However, a million flowers won't damage your sense of smell.
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