'Giant' Neuron Regulates 50,000 Other Neurons 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."
My dog (Score:2)
... he might know a thing or two about this...
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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? (Score:1)
What happens if this single neuron fails/is damaged?
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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.
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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
Re:Single Point of Failure? (Score:5, Interesting)
Re:Single Point of Failure? (Score:5, Insightful)
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.
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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 differen
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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.
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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"
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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.
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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 ;).
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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 t
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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
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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? (Score:2)
I wonder how much more similar P2P networks/algorithms are when compared to wetware neural networks like the brain...
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p2p is a square wheel compared to a handful of neurons.
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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? (Score:5, Insightful)
One more commonality: The media industry hates when you use it.
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One more commonality: The media industry hates when you use it.
Add to that...
"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?"
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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.
Blind Chance (Score:1)
This obviously the work of blind chance and natural forces operating over time. And we make fun by invoking the FSM...
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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.
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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? (Score:3)
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.
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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 (Score:5, Informative)
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
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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...
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Focus (Score:2)
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.
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and it is found in locusts. the whole swarm/herd mentality suddenly makes sense.
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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! (Score:2)
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It might not be permanent debilitation:
http://www.nytimes.com/2003/06/22/magazine/22SAVANT.html?pagewanted=1 [nytimes.com]
http://wireheading.com/brainstim/savant.html [wireheading.com]
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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...)
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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 e
This could be fun. (Score:2)
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 (Score:1)
does this explain telepathy, yet?
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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 f
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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.
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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 t
Nice summary ...not! (Score:5, Insightful)
"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."
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> 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.
In the fly... (Score:2)
For many reasons, there is almost certainly nothing like this in the mammalian brain.
Sorry, they are locusts (Score:2)
But the comment still stands.
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What are the reasons?
Something interesting from the article:
There is a negative feedback loop. I wonder if thi
Re:In the fly... (Score:4, Informative)
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.
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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
Probably holds a patent... (Score:2)
In Soviet Russian Giant Neuron regulates YOU!
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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?
Let me be the first to say it... (Score:2)
This research stinks!
That's not 'coding' (Score:1)
Right. Okay. (Score:2)
(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.)
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This is the mechanism used by Brain Slugs (Score:1)
interesting (Score:1)
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.
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