Scientists say nerves use sound, not electricity

[Trytostaydead]

Who knows, sound may play a PART in it. We discover more and more what makes the nervous system tick. Not being very physics minded, I wonder how they explain though patch-clamping of neurons that read the actual voltage differences inside and outside of the memrbanes

[Darth Servo]

"For us as physicists, this cannot be the explanation," said Thomas Heimburg, an associate professor at the university's Niels Bohr Institute. "The physical laws of thermodynamics tell us that electrical impulses must produce heat as they travel along the nerve, but experiments find that no such heat is produced."

Don't sound waves produce heat too?

The physicists say because the nerve membrane is made of a material similar to olive oil that can change from liquid to solid through temperature variations, they can freeze and propagate the solitons.

These proposed soundwaves shouldn't restrict themselves to neurons since all cell membranes are made of the same phospholipids as neurons.

The scientists, whose work is in the Biophysical Society's Biophysical Journal, suggested that anesthetics change the melting point of the membrane and make it impossible for their theorized sound pulses to propagate.

You know, this would be trivially easy to verify through experimentation, yet they apparently haven't tried. Just a bunch of "would-a, should-a, could-a."

[Spin Echo]

Are MRIs actually giant listening devices?

MRI machines use the nuclear spin of atoms in the sample to see what's going on, not electricity. They can't measure brain activity directly, so we have to work with techniques like blood oxygenation levels.

[Admiral Valdemar]

An EEG, however, can. Not only that, we're looking at game accessories in the near future that will use such systems to replace traditional input devices, making the Wiimote look somewhat lacking.

[Patrick Degan]

The scientists, whose work is in the Biophysical Society's Biophysical Journal, suggested that anesthetics change the melting point of the membrane and make it impossible for their theorized sound pulses to propagate.

Ridiculous. How would an anesthetetic affect the melting point of cellular material at all? And how does it explain away the EEG data which is regularly registered to monitor brain activity? How does it explain away nerve-conduction tests carried out even upon anesthestised patients?

I wonder how many neurologists are reading this article and laughing?

[Fingolfin_Noldor]

Before continue shooting, one shoot read the paper found at the link to the U of Copenhagen. They did some experiments and showed some of their results. I am no biophysicist since i don't have the biology background, but one with the background ought to read and interpret what they did.

http://www.biophysj.org/cgi/rapidpdf/bi ... 6.099754v1

A paper usually isn't accepted in a journal unless it has been reviewed properly, unless the editorial board is of low repute.

[Admiral Valdemar]

I've had a brief overlook of the paper, without going too much into detail, they seem to be saying because we don't fully understand the biochemical properties of certain modern agents used by anaesthetists, then that totally throws out the idea of electro-chemical neurone activity. In other words, because we can't fully explain an idea, much like one can't with a great many theories in science not fully complete, then an alternative must be proposed. They pick up some membrane and cytoplasm phase shifts that are well documented in biology, then see that solitons propagate differently in these mediums which come about via the addition of whatever agent for sedation you add. Hey presto, it must be sound that is causing a physiological effect! Rather like shooting someone in the head and thinking it was the loud bang that splattered their brains on the wall, not the slug.

It would seem these people are intent on trying to press an idea that, apparently, has been around a little while with some of the more fringe biophysicists in the world, much like how Sir Penrose is constantly going on about this idea of the quantum mind, which has yet to have any real empirical backing and which is constantly being dismissed by other scientists.

So yeah, heaping amount of bullshit that makes me wary of those so called scientists and the journal, which is either a soap box for these loons or sorely lacking in papers lately.

[Darth Servo]

I've had a brief overlook of the paper, without going too much into detail, they seem to be saying because we don't fully understand the biochemical properties of certain modern agents used by anaesthetists, then that totally throws out the idea of electro-chemical neurone activity. In other words, because we can't fully explain an idea, much like one can't with a great many theories in science not fully complete, then an alternative must be proposed.

Standard operating procedure for every fringe idea nutcase/conspiracy theorist/creationist/rabid stupid asshole trekkie.

[Shroom Man 777]

At least this will be a good thing for science fictionists. Aliens with nerves that use sound instead of electricity, cool!

[Darth Servo]

At least this will be a good thing for science fictionists. Aliens with nerves that use sound instead of electricity, cool!

Slower conduction of the impulse will be a GOOD feature of an alien species?

[Lord Zentei]

At least this will be a good thing for science fictionists. Aliens with nerves that use sound instead of electricity, cool!

Slower conduction of the impulse will be a GOOD feature of an alien species?

No, I think he means that it is a good thing for science fictionists to have another alien physical feature to play around with when designing their species (as opposed to the species themselves). More wierdness and variety, all that.

[Teleros]

Another question for them? What would the transmission speed of these "sound waves" be in a nerve cell? Because I'm pretty sure it'd lag behind an electrical impulse .

[drachefly]

Everyone agrees that the nerve impulses are carried by the motions of ions. Because they are ions, these motions interact with electrical fields. The sound waves will produce electrical fields and can be affected by them.

These people are just saying that the actual mechanism of signal propagation is better described as an ionic sound wave than as an ionic current. that doesn't mean there isn't actually also an ionic current. It just means it's incidental to the system, not a core feature.

As for the question of whether this is slower: No. First, sound goes faster in condensed systems than in gases. Second, electrical signals go much slower when there is stray capacitance. Considering that these nerves are embedded in an electrolytic fluid, there's a shitload of stray capacitance. Further, the ions themselves are the carrier, not the electrons. That slows everything down even further.

Now, whether they're right: beats me. But this is not vulnerable to the facile counterarguments presented.

[Admiral Valdemar]

Actually, what's facile is the abstract of this paper, which is rather iffy, especially when added to the rather typical, crappy mass media title from the CBC site which is the usual "scientists say..." as if all of science suddenly agreed on one thing, or science is some person working in government. That, and really, at the levels we're talking about the idea of sound acting as the encoder and propagator of information is pretty obscure, since one can already argue that the action potential causing an ionic wave then propagate at a synapse is, essentially, a form of sound. So in a way, this is semantics when you consider the fantastical headline some moron journalist made. It must be said, the idea some people seem to have of nerves acting like lives wires in a piece of man-made hardware is equally as backwards as the idea of nerves acting like the string in a tin can telephone. There is a very well documented electro-chemical effect caused by ionic balances and ligand binding within receptors. That Tasers can cause muscle spasms while me yelling at you can't (but it will irritate) is not proof that a purely electrical system exists, just that current can affect the cellular machinery in another way unlike certain proteins binding to plasmalemma bound receptor sites.

On the other hand, I'd like to see more done on this before openly embracing it given the current Hodgkin & Huxley models for neurone activity may be lacking, but at least function to explain most things well enough for now. I don't see the need to rewrite textbooks or anything more overblown than simply reminding people to accept that there may be more to the physiology of the nervous systems and their components than at first was believed.