Birdsong Studies Lead To a Revolution In Biology

Smithsonian.com covers research that began with the study of birdsong and ended by overturning the common belief that adult animals can't produce new brain cells. "Deconstructing birdsong may seem an unlikely way to shake up biology. But [Fernando] Nottebohm's research has shattered the belief that a brain gets its quota of nerve cells shortly after birth and stands by helplessly as one by one they die — a 'fact' drummed into every schoolkid's skull. [Nottebohm] demonstrated two decades ago that the brain of a male songbird grows fresh nerve cells in the fall to replace those that die off in summer. The findings were shocking, and scientists voiced skepticism that the adult human brain had the same knack for regeneration. ... Yet, inspired by Nottebohm's work, researchers went on to find that other adult animals — including human beings — are indeed capable of producing new brain cells. And in February, scientists reported for the first time that brand-new nerves in adult mouse brains appeared to conduct impulses — a finding that addressed lingering concerns that newly formed adult neurons might not function."

Comments

Thank god!

[Anonymous Coward]

Drink up, fellas!

Re:Thank god!

[metlin]

My thoughts exactly! Cheers, mate.

*hic*

Re:Thank god!

[truthsearch]

Homer no function beer well without.

Re:Thank god!

[dbet]

It's a bit of a myth that brain cells are killed when you drink. They are simply impaired.

So, don't drink because it's now safer, drink because it makes you better looking, funnier, and completely impervious to insults.

Re:Thank god!

[fractoid]

Or rather, as my chemistry teacher told me in highschool, it's not the alcohol that damages your brain cells, it's dehydration during the hangover. Stay well hydrated and you can get as tanked as you like. Your liver may hate you but your brain will be fine. :D

(I am not a doctor and neither is he, we both like alcohol though. ;)

Re:Thank god!

[Anonymous Coward]

Yes doctor!

Re:Thank god!

[Anonymous Coward]

Don't forget hitting your head when you fall over.

Re:Thank god!

[Anonymous Coward]

> It's a bit of a myth that brain cells are killed when you drink. They are simply impaired.

It's only a "bit of" a myth. Progressive alcohol poisoning, seen in chronic binge drinkers like George W. Bush, is the result of brain cells damaged and/or killed by oxygen starvation. The symptoms mimic early onset Alzheimer's, but as in the videos of our Mr. Bush drunk off his ass at the Olympics, patient history tells the real story.

Re:Thank god!

[BooRolla]

So it's the same as before?

Re:Thank god!

[StuffMaster]

Well, chronic heavy drinking does lead to loss of brain mass, which might be the source of the myth.

Re:Thank god!

[Anonymous Coward]

No, I feel like I'm dying. Teach the children. Funny it is, and I believe humor is essential. Still, this is a different world for these kids, and just because the brain keeps growing and learning doesn't mean it can function w/out the body. I can't have a single beer without puking. Give the kids ubuntu, not ubeertu.

Phew

[acehole]

I think I brain my damaged.

Re:Phew

[Locke2005]

My brain hurts!

Re:Phew

[zlel]

Make sure you get everything backed up. 'Cos now tech support will just replaced it with a new one.

Re:Phew

[Anonymous Coward]

Wow, a Monty Python reference. Clever.

well ya

[Dyinobal]

The whole "You only get so many cells" seemed counter intuitive to me. Logically it made very little sense. I never really cared though if it was true. I'm not a biologist nor did I ever do anything that would of required me to use such information. I always thought that You only get so many cell divisions seemed more likely. After all cells don't replicate perfectly.

Re:well ya

[John Hasler]

Read up on stem cells.

Re:well ya

[buswolley]

NO sh1+.

What do you thin is going on in the Dentate Gyrus region?

Itis fascinating, but not new news.

Re:well ya

[Itninja]

You know that female mammals only get one supply of eggs? Once their gone, their gone. Not really sure why the evolution god would give a women two million eggs....maybe they originally evolved to live for thousands of years. Or maybe we were only supposed to live 80 years, but have like 1.99 million kids. Or maybe early humans were like salmon with a 90+% infant mortality.

Re:well ya

[someone1234]

The second option is the correct answer. Say hello to uncle salmon.

Re:well ya

[Anonymous Coward]

Not all the eggs are good.

Re:well ya

[knarf]

that would of required me

May I advise you to make good use of this new knowledge by growing a few more cells here and there...

Re:well ya

[Hognoxious]

Some are only partially good. Tricky things, eggs.

Re:well ya

[vegiVamp]

I don't know shit about this sh1+ you mention.

Old News.

[dawgs72]

Holy 2002 Batman!

So now we can grow wetwear.

[paradxum]

This is actually very awesome as we have slowly made use of mice/rat brain cells as computing devices. This adds a whole new level, Just imagine a self-repairing/expanding computer... hmmmm maybe that's not such a good idea.

Re:So now we can grow wetwear.

[Maxo-Texas]

Op: Computer, please calculate the optimum trajectory to venus.

chee chee chee... working

Optimal path... CHEESE.

Op: Grr... Computer, please calculate the best stock to buy.

chee chee chee... working

Optimal stock... CHEESE.

Re:So now we can grow wetwear.

[Thinboy00]

No results for CHEESE... Is this close enough?

Re:So now we can grow wetwear.

[Anonymous Coward]

But the gimmick is that the lube goes on the inside.

Re:So now we can grow wetwear.

[Anonymous Coward]

No results for CHEESE... Is this close enough?

The cake is a lie.

Re:So now we can grow wetwear.

[Anonymous Coward]

I'm sure there is a joke in there somewhere about thinking with your dick.

Bird brain

[oldhack]

The new brain cells are still bird brain cells.

Re:Bird brain

[fractoid]

The new brain cells are still X brain cells because they were grown by the brain of an X.

Informative statement: If X = human then they'll be human brain cells.

Alternative funny statement: If they were grown by the brain of an ex they will probably be bitter and angry.

Re:Bird brain

[subgranules]

So nobody read TFA? It is from 2002. Research since then has shown that the mouse, rat and human hippocampus (specifically the dentate gyrus, the region that if destroyed produces antereograde amnesia, like in Memento) can grow new cells that replace old ones. This also happens in the olfactory bulb - a region that helps us tell the difference between similar odors.

Re:Bird brain

[L4t3r4lu5]

We'll have to come up with a whole new set of jokes, lads... This means they have the capacity to learn to reverse park.

Re:Bird brain

[Anonymous Coward]

No, it means they have the capacity to get a lot better at not being able to reverse park.

fat cells and muscle cells, too?

[panthroman]

I learned that nerve, fat, and muscle cells didn't change in number during life*. Seems that's not true about neurons. Apparently also not true about fat cells ("If excess weight is gained as an adult, fat cells increase in size about fourfold before dividing and increasing the absolute number of fat cells present.") Anyone know the scoop on muscle cells?

* - Supposedly weight gain was due to the individual adipocytes getting larger, like a microcosmic obesity. And strength gain was due to more actin and myocin in each myocyte, like a micrcosmic bodybuilder.

Re:fat cells and muscle cells, too?

[LeadLine]

I don't know where you studied, but as far as I know, you create tiny rips in your muscles when you work out and new cells are grown to bridge the tear.

Re:fat cells and muscle cells, too?

[__aasqbs9791]

Blasphemy! Each person only has 1 muscle cell that grows larger as they work out. /s

I learned the same things in school myself. We ere even taught that nerve cells didn't get repaired after they were damaged (to the point of dying). Oh, except in the tongue. Those were unique for some reason. And then we started learning that other nerve cells (like in the spine) did sometimes heal, but that perhaps the 'muscle memory' was lost, and learning to walk when you are an adult is much harder than it was as a child. At some point I think we may just have to say, "We don't know what we think we know, and maybe we should just start all over again." We stand on the shoulders of giants when we discover something new, but apparently sometimes it turns of those are midget's, not giant's shoulders, and we are forced to unlearn something we thought was true. Thus goes the ways of science.

Re:fat cells and muscle cells, too?

[dbet]

Muscle cells form long fibers but don't generally get "fatter" the way fat cells do. You can both gain and lose muscle cells depending on circumstance.

It's true that fat cells can grow and shrink as they are "filled". But laying new cells when you eat a lot is almost entirely a one-way process. When you lose weight the cells lose their stores, but don't disappear. This could be why it's easier to gain weight than to lose it, or why really fat people that lose hundreds of pounds have this flab that never goes away.

Re:fat cells and muscle cells, too?

[c_forq]

This is what I was told when I was a runner. The physical therapists had massages that would create tons of pain, but explained that the reason for this pain is they were creating new tears and expanding the ones caused by the work out while at the same time pushing lactic acid out of the muscle. Flushing out the lactic acid was supposed to help the rips heal faster (I have no idea if that part is true or not).

Re:fat cells and muscle cells, too?

[fractoid]

Anyone know the scoop on muscle cells?

I'm not a cellular biologist but I'd suspect muscles have a set number of fibres but that each fibre is made of many cells. Would that make sense?

Re:fat cells and muscle cells, too?

[izomiac]

Cells generally respond to being overworked by either hypertrophy (increase in number) or hyperplasia (increase in number). Realistically, most cells do both, although one method may dominate. Some Googling reveals that hyperplasia definitely happens in human smooth and cardiac muscle, and probably happens to some extent in skeletal muscle (animal studies demonstrate it). As far as neurons go, your olfactory neurons (responsible for smell) are actually constantly dividing as well (turn-over time of a couple weeks IIRC).

Something interesting about fat cells (adipocytes)... As they swell they secrete leptin, which reduces hunger and aims to keep one at a healthy body fat level. If a person becomes fat enough that the adipocytes have to divide (probably related to maximum surface area to volume ratio), then they have more adipocytes and thus more leptin produced. But, the clincher is that losing that fat becomes more difficult, since you don't get rid of the fat cells. What happens is that each cell is forced to become unnaturally small, which lowers the amount of leptin secreted. On top of that, the more leptin that floods the leptin receptors in the brain, the more resistant to leptin the receptors become (much like a Type II Diabetic is resistant to insulin). Less leptin receptor activation causes more hunger, and thus more difficulty in losing fat. Apparently, high levels of fructose accelerate this process. (All that said, fat levels are basically a matter of calories in/out due to the laws of physics; hunger just makes it more difficult to eat less and exercise more.)

Re:fat cells and muscle cells, too?

[chooks]

Each person only has 1 muscle cell that grows larger as they work out.

Ah yes, the love muscle...In most slashdotters this is pretty well atrophied from disuse - at least until the pics of a statue of a naked natalie portman covered in hot grits shows up on the intertubes.

Re:fat cells and muscle cells, too?

[Hurricane78]

No. That it outdated knowledge and is actually an overworking of your muscles. I know that it's stated again, and again, and again, by people who seem to be experts by all standards. Yet there is proper proof that it's not the right way to get stronger, and actually creates scar tissue. So you might get bigger muscles, but not really stronger ones! The strength comes from the tissue that did *not* rupture,and was allowed to grow.

So it's better to lift a lighter weight more often, than a heavier one just a couple of times.

Re:fat cells and muscle cells, too?

[chooks]

The new cells come from myoblasts that differentiate from satellite cells that exist in the muscle tissue. The damaged muscle cells release signals that cause the satellite cells to do this. The myoblasts in turn develop and fuse together to form the mature multi-nucleated myocytes. In addition to forming myoblasts, the satellite cells also divide to replenish (to a limited extent) the satellite cells that turn into myoblasts.

And it has been known for several years that neuronal stem cells exist in the human brain. Specifically, the hippocampus (C3 layer I think, but not sure and not willing to look it up right now) contains some capability for regeneration. Not a lot granted, but the capability does exist.

Re:fat cells and muscle cells, too?

[Anonymous Coward]

It's been known for over a decade now that human brain and nervous system cells, (including spinal), can grow spontaneously and/or regenerate. The key is nobody has figured out yet what triggers it.

Re:fat cells and muscle cells, too?

[lennier]

"outdated knowledge"

Isn't that a contradiction in terms? If it's wrong now, it was just as wrong when it was being taught... knowledge doesn't get "outdated". Opinions and beliefs and fashionable ideas may change... but not actual *knowledge*.

Pedantic, I know, but I get creeped out by the subtle assumption that somehow the very foundations of reality change under us as the scientific consensus shifts. This sort of abuse of language and the misidentification of beliefs, teachings and opinions with fact, is exactly why the man in the street has grown to distrust "science".

I'm pretty horrified myself if this "muscle tearing" thing is in fact incorrect - because that's what I was taught in high school gym class. It sounded stupid and abusive to me at the time - why should destroying muscle be a *good* thing? - and it was used to justify the "if it doesn't hurt you're not doing it right" idea. If it turns out that that was a flat lie all along... yeah, I'm pretty pissed off. Shouldn't we hold off making *any* such "scientific" pronouncements until we're darn sure, for good and all, that we're NOT just saying crazy wrong things?

Re:fat cells and muscle cells, too?

[Anonymous Coward]

Fat cells absolutely divided, but as far as I know, they rarely become apoptotic (normal cell suicide). So as you gain weight, you get more, but when you lose weight, the ones you have just flatten out. This is why it's incredibly easy to gain the weight back.

Muscles cells, for nearly all normal physiological conditions, including building muscle, do not divide. They can, but it's rare and almost always pathological. An example of the very rare exception would be a rhabdomyocsarcoma, muscle cancer.

Re:fat cells and muscle cells, too?

[lennier]

I mean, the current accepted philosophical basis of science is Karl Popper's falsifiability criterion, which is not a monotonic logic... yet we don't have anything like a universally accepted formalisation of nonmonotonic logic to deal with this kind of situation (where something believed 'true'at time A becomes 'false' at time B when new facts emerge). There's no standard way of dealing with this in logic - much foundational work was only *started* in the 1980s and the results are still very unclear. So the formal philosophical foundations of our current scientific paradigm are a massive pile of confusion. Yet we're charging ahead using science to make sweeping technological and social changes without properly thinking them through - without even the guarantee that we CAN think them through consistently. Shouldn't that worry us a lot more than it does?

Re:fat cells and muscle cells, too?

[RobinEggs]

stand on the shoulders of giants

Despite its eternal popularity, this quote doesn't connote meekness or high hopes for scientific progress. When Newton spoke these words he did so not because he felt star-struck or humble, but so might he insult another scientist who happened to be a midget.

So stop quoting it like some sage wisdom out of scientific history. Please.

Re:fat cells and muscle cells, too?

[radtea]

Anyone know the scoop on muscle cells?

Like everything else, it probably varies with person. My strength has increased about 50% in the past nine months (check out the Big Five workout and the book "Body By Science"--best workout I've ever used.) but my bulk has hardly increased at all--I'm a hard gainer.

This is also true of the brain, as anyone who has studied anything about strokes in the past 20 years (since the advent of CT) has known: some people have highly plastic neurological function, so the destruction of some areas does not necessarily permanently decrease the function that those areas nominally supply.

Only idiots who believe their grade-school view of the brain implicitly are surprised by any of this.

Re:fat cells and muscle cells, too?

[radtea]

So it's better to lift a lighter weight more often, than a heavier one just a couple of times.

People differ. I've had more gains from "one max rep" style workouts (where you start at the heaviest weight you can do a single rep with and work down) than anything else. Anyone who believes there is one single optimal workout for all people is ignorant of the real, empirical variation between individuals and not qualified to give workout advice.

Re:fat cells and muscle cells, too?

[edible_seaweed]

Why Newton said it is completely irrelevant -- the sentiment is interesting, inspiring and useful in its own right, and that's why it has survived on its own right, not as sage wisdom out of scientific *history*, but sage wisdom out of scientific *tradition*. It should not be judged as a "quote" based on its origin, but as a saying, based on how people mean it today, in which case you're entirely wrong -- the saying *does* connote meekness and high hopes for scientific progress.

Re:fat cells and muscle cells, too?

[Toonol]

If that's all there was to it, Newton would have said "Leibniz, you're short."

Instead, he constructed a grand and insightful statement about science that just so happened to carry a veiled insult. Nothing wrong with that, and it doesn't detract from the meaning of what he said.

Re:fat cells and muscle cells, too?

[Jedi Alec]

As someone who is tall, slim and has relatively long and narrow muscles, I've always profited most from the "lots of reps with light weights" approach. I don't seem to accumulate any more muscle mass, my weight stays pretty much the same but I can squeeze out a lot more performance from the same muscles without the downsides of lots of actual muscle mass(and without the upsides of looking ripped, if there are any).

Like you said, people differ :-)

Re:fat cells and muscle cells, too?

[plastbox]

Also, there are different gains from different types of set/rep combinations. Tons of professional strength athletes and body builders can attest to this being true, even if the mechanics behind it are a bit fuzzy. If you do 5 sets of 5 quick lifts with a good pause in between sets, you force your body to adapt to that intensity and duration, building mostly explosive strength and some mass. If you do 1x15-20, lifting slowly on the negative (4-6 seconds) you build more mass than explosive strength. You of course get stronger with all resistance training but set/rep combinations determine whether you gain more strength or mass.

One golden rule is that if you complete the last set on any given exercise, you're not lifting quite enough. Another one is variation. Change your workout program every couple of months or so. The body is master of adaptation and growing muscle is expensive, so after doing the same intensity/duration for a while your body optimizes for it and you hit a plateau.

And muscular scar tissue from working out..? I don't buy it. Resistance workouts lead to better blood flow in the muscle tissue, stronger neural paths (the reason the first three months or so you can experience an insane ~20% strength increase) and, you know... increased strength.

Re:fat cells and muscle cells, too?

[Crafack]

Short answer: No.

If you look at the history of "modern science", from circa Newton and forward, the hard science has been separated from philosophy.

In a way you can say that the philosophers are constantly trying to catch up, and integrate the new knowledge in their world perceptions.

As a whole I do not think that is a problem. We might occationally stumble upon a field or a method that we in hindsight can see was a bad idea, for ethical reasons, but the checks and balances that is built into academia and science/science funding will soon enough learn to handle these areas (and perhaps give the philosophers a helping hand in the process).

I see philosophy as contemplative and reactive to the given facts. If we insist that all science must keep pace with philosophy, we will stifle progress enough to start a new "dark age". /Crafack

Re:fat cells and muscle cells, too?

[plastbox]

So where can I get this rhabdomyocsarcoma if which you speak?

Also, does it turn your skin green..?

Re:fat cells and muscle cells, too?

[L4t3r4lu5]

I was always told to build tone, not mass, anyway. Muscle mass makes you look like an upturned triangle. Tone makes you look like an athlete.

Re:fat cells and muscle cells, too?

[MaGGuN]

So it's better to lift a lighter weight more often, than a heavier one just a couple of times.

I don't know where you get this from but it's complete and utter bullcrap. Your statement alone is incomplete at best, with references to 'lighter weights', 'couple of times', it does not get any more vague than that. Don't listen to this folks, weightlifters don't exclusively do lighter weights and many repetitions simply because it is not optimal for pure strength. If you lift weights regurarly following a program even only for one year, you will know from experience that you need to stress and overload your muscles to build strength. That means you need to put on heavy weights to get maximum return from your effort. But remember that a complete traning program does not exclusively contain weightlifting exercises with many/few repetitions. Many repetitions is usually for warmup, softening the tendons and attracting blood to the muscle, this avoids injury and improves metabolic response. It also prepares the muscles for heavier weights, that is why you usually build up before you do heavy weights, muscles need to adapt for best response. There are many philosophies when it comes to weight lifting for strength, but I guarantee you that none of the successfull one's is according to quoted statement.

Re:fat cells and muscle cells, too?

[Anonymous Coward]

This is oversimplified to the point of being completely wrong. Over 5 reps is cardio to most powerlifters.

Re:fat cells and muscle cells, too?

[steelfood]

In a way you can say that the philosophers are constantly trying to catch up, and integrate the new knowledge in their world perceptions.

Only the analytical philosophers, and that's because they limited themselves to "reality," and as such, since reality is best defined by science, they're limited by what science says it reality is.

Philosophy doesn't require science; it is much more vast, much greater, than science. The universe itself (of which science is mainly regarding) cannot encompass all the possibilities of thought. Science, or really, the scientific method itself is a philosophy of truth.

Analytical philosophy is a fad, one which, funny enough, came into prominence as science and engineering came into prominence. Personally, I think a lot of philosophers are insecure, and as such, turn to a stabler basis to form their ideas. It's not wrong, but it's severely limiting, which is probably why the latter 20th century hasn't borne too many interesting philosophies, just lots of people debating about past philosophies.

In fact, that you think analytical philosophy is all there is to philosophy indicates to me just how far the scholarly field has truly fallen.

Re:fat cells and muscle cells, too?

[gymell]

So it's better to lift a lighter weight more often, than a heavier one just a couple of times.

No, the only thing that lifting lighter weights more often will give you is the ability to lift light things many times. That's called endurance. Lifting heavy things less often will give you the ability to lift heavy things. That's called strength. Which one is "better" for you depends on your fitness goals.

Re:fat cells and muscle cells, too?

[coolsnowmen]

I think if you are going to be that pedantic. then it is still ok because of what knowledge means.
Knowledge does NOT mean "what is true."

Knowledge is what is in your brain after learning from the outside world, and reasoning it out yourself.

It is very possible to learn things, and commit them to your knowledge, and still have those things not be completely true, or down right false.

The Student Body

[Anonymous Coward]

And college students everywhere celebrate this news with a glass of beer!

Me, too!

[WheelDweller]

Science does silly things like this sometimes. Healing wounds? Sure! We'll make more cells. Oh, but no: BRAIN cells are magical and can't be replaced.

I'm sorry, with as many animals as there are (lots of diversity of breeds!) and humans seeing SO many animals in their lifetimes (just consider dogs and cats alone) if there were normally cells that actually could not be replaced, wouldn't that render them 'crazy' (for the brain) or leave gaping holes in muscle tissue, or similar? To rule this out sounds like another standard I heard:

Take a june bug, large and green...tie a string to it's leg and let him fly in circles. At the point where he starts to BLUR, that must be the speed of light. Figure the scale based on RPMs, etc the usual way.

SO: Speed of light: 34 mph!

Seriously: this standard stood for something like 700 years. Science: imperfect.

Re:Me, too!

[Cassius Corodes]

That story about the speed of light sounds like bullshit. Couldn't find any mention of it on the inter-web, and wikipedia has no mention of it. Citation plz.

Its called neural plasticity

[Anonymous Coward]

I learned over a decade ago that nerve cells in the brain can grow, regrow, and remap themselves.

It's called neural plasticity, and is a well-documented phenomenon. If brain cells were immutable, how do you think people would be capable of learning????

If I learned this as an undergrad over 10 years ago, I don't see how this turns any 'establishment' on its 'head'.

Re:Its called neural plasticity

[plastbox]

Of course they are able to "grow" and remap themselves. What is generally taught is that they do not generally divide to replace dead or damaged nerve cells. If you cut away a piece of skin, the cells in that area divide until the wound if closed (or that's the way it's supposed to work, at least). If you kill a piece of your brain, there is (according to general "knowledge") no way to regenerate these lost cells.

Well, duh.

[pclminion]

I don't mean "duh" to the researcher -- obviously things must be tested and validated in the real world, not just postulated -- but it never made sense to me in the first place that brain cells can't regenerate. Why the hell not? What is the adaptive purpose of such a limitation? The brain consumes a huge amount of energy, much more so per-pound than any other organ in the body. That seems to imply that the brain is extremely important to the organism. Why would essentially the most important organ in the body have such a stupid limitation that it can't even recover from MINOR damage? That makes no sense.

One possible explanation for the very limited growth rate of brain cells is that if this growth rate were not tightly controlled, it could lead to "chaotic" brain tissue which could interfere with normal brain function. So general division of brain cells would not be desirable -- but I'm no neuroscientist.

Re:Well, duh.

[gtbritishskull]

Cancer is the uncontrolled division of cells. I could see an evolutionary incentive to stop all (or most) cell division at some point, so that the cells that are dividing (cancer) can be controlled and eliminated by the body.

But I do agree with you. I always thought they had it wrong too.

Re:Well, duh.

[thebjorn]

It's called apoptosis (http://en.wikipedia.org/wiki/Apoptosis even has a cute picture for the foot-fetishists out there ;-).

Re:Well, duh.

[DynaSoar]

I don't mean "duh" to the researcher -- obviously things must be tested and validated in the real world, not just postulated -- but it never made sense to me in the first place that brain cells can't regenerate. Why the hell not? What is the adaptive purpose of such a limitation? The brain consumes a huge amount of energy, much more so per-pound than any other organ in the body. That seems to imply that the brain is extremely important to the organism. Why would essentially the most important organ in the body have such a stupid limitation that it can't even recover from MINOR damage? That makes no sense.

One possible explanation for the very limited growth rate of brain cells is that if this growth rate were not tightly controlled, it could lead to "chaotic" brain tissue which could interfere with normal brain function. So general division of brain cells would not be desirable -- but I'm no neuroscientist.

I am, and you're right in nearly every detail. I'd only add:

- New growth would consume energy that the very hungry brain would prefer not to waste that way.

- Brain function develops by strengthening some of its connections, but losing far more. You're born with 4 times the connections you die with. There's no need for new cells in terms of function.

- It actually is in repair that 'chaotic' growth occurs. Neurons are notoriously stupid when it comes to regrowing back in the same place. Severed nerve trunks try to grow back together but get tangled and miss connection, make incorrect connections, or simply turn back on themselves in a tangled "stump neuroma". Some (but not all) of this occurs because the 'interneurons' that act as the telephone poles to the neural wires also get damaged and/or die.

- There's good progress made in getting neurons to regrow and reattach properly, using techniques of treating the cut nerves with certain things and/or using host stem cells. I'm not fully up on the details, but I will be once I read a copy of my son's dissertation; he defended it last month and is just finishing the revisions. I do know that in some cases even severed spinal cords could grow back correctly enough for partial function if treated soon enough with a particular substance. That substance is a common food additive, so phase 1 clinical trials might be skipped. The hope is an injectable treatment would be available to emergency workers which, if the testing bears out the initial studies, would give people with severed nerves more than half their original function in more than half the cases.

Re:Well, duh.

[tomhudson]

I don't know - the thought of my brain cells continuing to divide makes my head 'splode!

Re:Well, duh.

[tomhudson]

I do know that in some cases even severed spinal cords could grow back correctly enough for partial function if treated soon enough with a particular substance. That substance is a common food additive,

So junk food is good for you. You could even say it is "brain food."

Re:Well, duh.

[pclminion]

I do know that in some cases even severed spinal cords could grow back correctly enough for partial function if treated soon enough with a particular substance. That substance is a common food additive, so phase 1 clinical trials might be skipped.

You may have ethical reasons for being vague about what exactly this "substance" is, but given what you've said here, I'd wager you're talking about glutamate?

Re:Well, duh.

[atamido]

There was an article a few months back about using blue food dye in spinal cords immediately after injury having a significant effect. Possibly this is what you are thinking of?

Re:Well, duh.

[DynaSoar]

I do know that in some cases even severed spinal cords could grow back correctly enough for partial function if treated soon enough with a particular substance. That substance is a common food additive, so phase 1 clinical trials might be skipped.

You may have ethical reasons for being vague about what exactly this "substance" is, but given what you've said here, I'd wager you're talking about glutamate?

Glutamate is a transmitter precursor, not a growth promoter.

I didn't know whether the news was out about this stuff or not so I had to find out first. Turns out I'm way late in catching up on my son's work. The Wikipedia page on this stuff references a 2001 study done at Purdue; that was the lab he worked in as an undergrad.

Polyethylene glycol. Since 2006 it's been allowed as a direct additive http://www.epa.gov/EPA-IMPACT/2006/March/Day-13/i2354.htm

Go to PubMed http://www.ncbi.nlm.nih.gov/sites/entrez and put in "polyethylene glycol spinal cord" as search terms.

Re:Well, duh.

[BadOctopus]

I'll see your 'Duh' and raise you a 'not really news'.

See this BBC News article from 2000 which describes how, "part of the hippocampus grew larger as the taxi drivers spent more time in the job." Navigating the streets of London for a job requires more spacial memory and reasoning so that bit of the brain grows.

Hardly a breakthrough or a suprise, unless I'm missing something?

Re:Well, somebody's gotta say it

[Anonymous Coward]

Guys, I think he's serious!

Settled science

[Kohath]

So a scientific view that is considered the "settled" "consensus" view can change in the face of contrary evidence? That's good to know.

Re:Settled science

[fractoid]

Um, what? You say that like it's a bad thing. I bet you also call politicians "flip-floppers" and say they have "weak leadership" when they change their policies based on global and local events. There's a place for unquestioning adherence to the status quo, but that place is not in scientific research.

Oh wait, I get it, you're a troll parodying those Intelligent Design drones. Damn, you're good.

Re:Settled science

[SpinyNorman]

Saying "i've never seen it" or "i don't expect to see it" is not science. One's just an observation, and the other not even a prediction, yet alone a theory.

You may as well call "i don't expect to see margaret thatcher's bare ass" science. It's not, even if you're wearing a lab coat when you say it.

Re:Settled science

[pclminion]

I don't see why the parent post was rated "Troll", nor do I understand the other replies to it. The parent is expressing that "There's hope for us yet." We can hold very entrenched scientific ideas, but are not unwilling to discard them when presented with evidence of their falsity. This is a good thing, and I think the OP was just pointing it out.

Re:Settled science

[DynaSoar]

So a scientific view that is considered the "settled" "consensus" view can change in the face of contrary evidence? That's good to know.

That's exactly correct. That's precisely how science works, and it wouldn't work any other way. When you continue to believe something in the face of contrary evidence, that's called being (1) irrational, (2) stupid, or (3) both. Had you paid attention when the teachers were trying to explain this, you wouldn't be (1), (2) or (3).

But I will add that, as noted below, just because you're (1), (2) or (3), you're only wrong, not trolling. Someone who mods a comment down just because it's wrong is both (2), and (5) an asshole. A troll would be something like my using the missing (4), inserting into in the comment in the paragraph above following the first (1) (2) (3), to say something like "or (4) religious". While accurate, it is inappropriate, and therefore a troll. So don't do it. Not even if you're (5) like me and think it's funny.

Re:Thank Cliff!

[dsginter]

In an episode of "Cheers," Cliff Clavin, the trivia-spouting, quirky, irksome mama's boy mailman is seated at the bar describing the buffalo theory to his buddy, Norm Peterson, the beer loving heavyweight bar stool sitting perpetual patron.

Cliff expounds his "Buffalo Theory" to Norm:
Well, you see, Norm, it's like this. A herd of buffalo can only move as fast as the slowest buffalo. And when the herd is hunted, it's the slowest and weakest ones at the back that are killed first. This natural selection is good for the herd as a whole, because the general speed and health of the whole group keeps improving by the regular killing of the weakest members.

In much the same way, the human brain can only operate as fast as the slowest brain cells. Now, as we know, excessive intake of alcohol kills brain cells. But naturally, it attacks the slowest and weakest brain cells first. In this way, regular consumption of beer eliminates the weaker brain cells, making the brain a faster and more efficient machine.

And that, Norm, is why you always feel smarter after a few beers.

Revolution?

[jcaplan]

Don't get too excited yet. As the article states in humans the only well-established generation of new nerve cells occurs in the hippocampus, a structure which conveniently is involved in memory.

There was another study dating cells based on inclusion of radioisotopes left over from atmospheric nuclear weapons testing, apparently finding a very slow rate of new cell generation, measured in something like percent (or fraction thereof) per decade of the total. And their study only holds true if they correctly sorted their neurons from other cells that live in the brain (glia, blood vessels, etc). The study is actually pretty convincing, along with the Swedish BrdU study, but the rate of growth is less than stunning. The findings in birds of huge amounts of cortical growth are very cool and establish the principle that such massive growth can happen in an adult vertebrate.

What has not yet been established is what these new cells in humans might be doing, if anything. Even without new neurons, we can still be pretty flexible, by altering the strength of connections between neurons or forming entirely new connections.

Also even if the human brain does grow some new cells, the type of those cells is very important. for example, I heard a talk today from a guy with Parkinson's disease, which is a progressive disease of the cells of the substantia nigra, an area of the brain that is part of the system for controlling movement. He sure could use a few extra dopaminergic cells in his substantia nigra, but thats not happening for him, so the disease will kill him. So don't go on that brain cell massacre just yet.

Re:Take that Dawkins!

[Cassius Corodes]

I disagree - ridicule is a powerful way of socially marginalising people and discouraging other people from taking them seriously. God (in the common religious sense, not the abstract philosophical sense) has been unable to fit in our current scientific knowledge about the world for quite some time, but this has not stopped nonsense from being believed. While it is important not to stoop to dishonesty and etc, all those who are scientific leaders of a kind have to be forceful in calling out folk who peddle nonsense rather than simply ignore them.

Um...

[raiderx]

Are you guys really this excited about news from 7 years ago?

Wiki: Neurogenesis

[Anonymous Coward]

Wiki: Neurogenesis

I must be new here... If yer not going to RTFA (Read The FU^H^Hfine Article), who's going to read wiki?

Weed

[Mr.Bananas]

Light up a spliff if you got 'em, those brain cells will grow back, dude

Beliefs of scientists

[tsa]

It's amazing how strong many scientists believe in certain things that are not even theories, and have a hard time changing their minds in the face of evidence to the contrary. We saw it with 'junk DNA' (long strands of DNA between genes that apparently had no purpose, so scientists decided it must be junk left over from evolution), stem cells, and now the dogma that certain types of tissue can't regenerate. Luckily they are proven wrong time and time again, which keeps biology exciting and opens new possibilities in medicine and health care.

Re:Beliefs of scientists

[DynaSoar]

It's amazing how strong many scientists believe in certain things that are not even theories, and have a hard time changing their minds in the face of evidence to the contrary.

Why should we scientists be any different from the rest of you? We're people acting like people do, we just happen to be trying to figure things out in public. Besides, we have to believe something as a starting point so we can test an idea, and when we do have evidence, develop a theory which we can then further test to find out where we're wrong, discard that, and repeat the process. A science example of this is solar neutrinos. Despite many well designed experiments using well tested devices, only one third of the predicted amount was observed. None would be a failure, but a consistent one third? That would call for changing the theory. But they didn't. After decades someone came up with an idea of how the theory was right, but neutrinos themselves acted differently than expected. The same design was used to test the old solar neutrino theory plus the new neutrino behavior theory, and the found the solar neutrinos, oscillating between types. They didn't change their minds in the face of evidence and ended up correct.

It's also amazing how people, including us, refuse to believe something new (as opposed to just different from previous beliefs) even when well supported by evidence. A science example is the 80% positive replications of chemical transfer of learning. Even a colleague of James McConnell, the guy who started this field (and the Journal of Biological Psychology/Worm Runner's Digest), wrote in his obituary in science about this "failure", correct in his statement with respect to the field but wrong as a football bat about the theory. Scientists didn't change their minds (or come to believe something) in the face of evidence, and still haven't, and they're wrong.

Then there's conflicting theories. The two major theories of emotion are that we notice a physiological response, then attach a significance to it. The other is that we notice something, develop a cognitive response, and that causes a physiological response. Completely backwards from each other. Neither side would let go because they had plenty of evidence. After a while it came to be understood that both were right, it was emotions that occurred differently in different cases (phobias and PTSD, respectively).

And recall Einstein being interviewed when Eddington was going to measure light curvature around an eclipse to test relativity. When asked what would happen if the data were contrary to the theory, he said "then heaven help the data. The theory is correct." Eddington came back with some data and said he'd proved the theory correct and everybody believed it, and many still do. It was 70 years before a different test proved the theory correct. Subsequently, it was shown that the errors rate in the few measurements Eddington had were insufficient -- he was wrong, and so were everyone else that did and do believe his claim.

Three of these four examples are from "The Golem" by Collins and Pinch. That book very thoroughly and with references speaks to your observation but in all these different aspects, and more. It's simply the best source of examples of science being conducted as a human endeavor by plain old normal humans with human behaviors. It's instructive, illuminating and quite entertaining. And in the case of things that are correct but people continue to disbelieve, such as cold fusion, quite irritating. As a scientist that last bit, to quote Spock, "thrills me no end."

Utter bullshit

[Anonymous Coward]

Take a june bug, large and green...tie a string to it's leg and let him fly in circles. At the point where he starts to BLUR, that must be the speed of light. Figure the scale based on RPMs, etc the usual way.

SO: Speed of light: 34 mph!

Seriously: this standard stood for something like 700 years. Science: imperfect.

Wikipedia: Speed of light, history

Physics.virginua.edu: Speed of light

Worsleyschool: Measuring the speed of light

Early, scientific attempts to measure speed of light were very... Well... scientific. And quite accurate. In 1021 an Iraqi physicist realized that light has finite, variable speed that is slower in denser bodies.

In 1629-1667 there were several tries to measure how long it takes for light to move two miles. They all however got to the conclusion that it couldn't be measured because light's speed was so high and human reaction speed could not keep up

In late 1600s astronomers tried to find out the speed of light by observing the moons of Jupiter. They finally got pretty close to the actual value.

It's limited

[ShooterNeo]

Fact is, regeneration of brain cells is very, very, very, very limited. In the case of severe brain injuries, it basically doesn't happen. (the reason recovery is possible is due to rerouting around the damage by cannibalizing existing cells). This depressing fact has been well known to neurologists and neurosurgeons for at least 50 years. Now, as it may turn out, there actually IS a little bit of regeneration. That doesn't change the fact that even if it happens a little bit, for all practical purposes brain damage is still permanent.

Re:It's limited

[Anonymous Coward]

If you cut off your hand or foot, it doesn't grow back either. Cell regeneration is able to repair smaller injuries, but not severe injuries in any part of the body.

Seems to me the brain is not special.

Re:It's limited

[Anonymous Coward]

unless of course new medical therapies can (ab)use the regeneration process mechanisms and speed it up.

Re:It's limited

[BobMcD]

Take the example of a Hemispherectomy. A huge portion of the brain can be disabled, and depending on the patient, relatively few complications result.

Think about the redundancy built into that system that would be necessary for this to happen.

What depresses me is the notion that brains aren't going to get better. It seems more like, if we could remove the damaged portion another would eventually take over. Coupled with this new 'new brain cell' information, now I'm wondering if we should be trying to find a way to encourage the brain to heal. Perhaps removing the scar tissue? I'm guessing, obviously, but this should be very exciting news indeed.

who came up with this silly idea, anyway?

[Johann Lau]

who was the first to claim brain cells can't regenerate, and what reason did they have for their claim? why did anyone take them seriously to begin with?

Re:who came up with this silly idea, anyway?

[Thiez]

I beg your pardon? You admit not knowing who came up with that idea, and that you have no idea what evidence they had for their claims; that is, you have no idea at all what the fuck you are talking about, and yet you somehow think you have the right to imply scientists who are no doubt far more knowledgeable when it comes to (neuro-)biology than you are should not have been taken seriously. You, sir, are an asshole.

Guess what. If you seriously damage some part of your brain, it won't (significantly) recover. If that part of your brain was responsible for some function, you will either lose that function, or other areas of your brain will (partially) take over that function or compensate in some other way. If you damage your spinal cord you may never fully recover. Every day neurons die that don't get replaced.

The idea that adult animals don't produce new neurons is NOT silly. For a long time there was no evidence that new neurons were being created and the creation of new neurons was not required to explain what we knew about the workings of the brain. Even now it can probably be compared to classical mechanics: it is 'true enough' in most circumstances.

Don't take my word for it, go read about biology. It shouldn't take long for you to realize that it is your post that is silly, not the idea that you criticize therein.

Re:who came up with this silly idea, anyway?

[Johann Lau]

scientists who are no doubt far more knowledgeable when it comes to (neuro-)biology than you

Haha... except the bit where they had wrong what I had right.

Guess what. If you seriously damage some part of your brain, it won't (significantly) recover. If that part of your brain was responsible for some function, you will either lose that function, or other areas of your brain will (partially) take over that function or compensate in some other way. If you damage your spinal cord you may never fully recover. Every day neurons die that don't get replaced.

Well...... duhhhhh?? What does that have to do with anything? Is that part just there to give some air of importance to the rest?

The idea that adult animals don't produce new neurons is NOT silly. For a long time there was no evidence that new neurons were being created and the creation of new neurons was not required to explain what we knew about the workings of the brain.

So instead of saying "we haven't seen new neurons been produced" they said "new neurons are not produced"? Yep, that is silly, and my original point still stands. Save your ad-hominens for someone dumb enough to fall for them ^^

Science is a discourse, not a religion

[microbox]

The history of science is full of consensus breaking ideas. Science is a discourse, not a religion. The only sacred truth is that there is no sacred truth. The consensus, however, can only be broken by _evidence_. So creation scientists and AGW deniers are out of luck.

brains own

[Yaos]

They need to figure out why only very tiny portions of the brain will grow back, and not huge parts.

Re:brains own

[tomhudson]

They need to figure out why only very tiny portions of the brain will grow back, and not huge parts

Maybe it's because the adult skull is rigid - if large parts grew, you head would explode! Or at least your eyeballs would pop out.

You need to flip the switch

[Blue Stone]

http://www.youtube.com/watch?v=B_m17HK97M8

And they also always said...

[Anonymous Coward]

That if you leave the seeds in you will go sterile...I learned that wasn't true either. ;)

Maybe there's hope for me after all the cells I killed when I was younger..

Re:Thank Cliff!

[Anonymous Coward]

> And when the herd is hunted, it's the slowest and weakest ones at the back that are killed first.
> In this way, regular consumption of beer eliminates the weaker brain cells,
> making the brain a faster and more efficient machine.
> And that, Norm, is why you always feel smarter after a few beers.

Oh. And here I thought alcohol slowed down the whole herd, making the weak ones in the back (for once!) just as fast as the regular ones...

Re:Thank Cliff!

[The Archon V2.0]

Oh. And here I thought alcohol slowed down the whole herd, making the weak ones in the back (for once!) just as fast as the regular ones...

How did you get that many buffalo drunk?

Re:Thank Cliff!

[RockDoctor]

How did you get that many buffalo drunk?

By taking them to drink at the rivers of beer draining the slopes of the Beer Volcano, just next door to the Stripper Factory in Pastafarian heaven.

What do you mean - it's not real? But I thought all ... well, I thought ... well, maybe I didn't think at all.

Brain Cells vs Fat Cells

[MarcIrvin]

Now can someone definitively disprove the newly evolving myth that at birth we have all the fat cells we ever have, and after birth they only swell or shrink according to our diets.

biology is not destiny

[brre]

We see a lot of confusion on that point. "It's in your genes, there's nothing you can do about it". Oh? Bad eyesight was in my genes. I got eyeglasses.

The plasticity of the brain was already known to be very high. Now we have reason to believe it's even higher than previously known. Genes are great, I love 'em, but a lot happens after conception.