This later article uses a cable model (implemented using finite element analysis) to make the case of factoring in tissue capacitance while predicting volume-of-tissue-activated,a common figure-of-merit in functional electrical stimulation. Therefore, having an estimate of membrane capacitance (that imparts rectifying properties) maybe key in the choice of stimulation frequencies.

https://www.researchgate.net/publication/7636239_Tissue_and_electrode_capacitance_reduce_neural_activation_volumes_during_deep_brain_stimulation

Article Tissue and electrode capacitance reduce neural activation vo...

Thank you for the answer, but the question was slightly different. Is it generally accepted this statement and are there experimental work supporting it?

(As you say: MAYBE)

Yes, nerve fibre membrane, and in general biological membranes, rectify due to their peculiar nonlinear electrical properties.

I think that Cole's classical book "Membranes, ions and impulses" (last edition in 1972) could be a good place to find experimental evidence and theoretical derivations of membrane's rectifying properties.

Yes, nerve membrane rectifies. See:

p229 Membrane rectificaton in "Jack, J.J.B., Noble, D. & Tsien, R. (1975). Electric current flow in excitable cells. Oxford"

or better:

p503 => Fig. 17 in "Scott A (1975) The electrophysics of a nerve fiber. Reviews of Modern Physics 47(2) 487-533"

If you need an explanation I have one in my paper:

https://www.journals.uio.no/index.php/bioimpedance/article/view/296

No, nerve membrane cannot do that. However, it depends on what it is defined for "rectification". If you excite a nerve with a sinusoidal signal of about 5 mV at 1 KHz, you may trigger the membranes on that nerves which will produce a voltage level of about 100 mV. This happens for the positive cycle of the signal but the membranes will not do anything when excited by negative cycle of the signal. Thus, you may say that it is a "rectification" as the membranes are only triggered by the positive cycle of the excited signal. Therefore, this is not a real rectification as defined in the electrical circuits.

Any nonlinear resistor has a "rectification" term.For details have a look at the theory of the RF diode rectification of a Schottky diode..essentialyl it all boils down to the second derivative of the I/U characteristic..that why an RF diode can "see "or generate a faint DC signal from Rf signal which are well below the "knee"(around 0.7 Volt) of such diodes.

Nerve membranes cannot be represented by a RC network. Furthermore, it cannot generate any DC signal. It has to be emphasized that at low voltage level the nerve membrane behavior is almost linear.

Hi Pedro

what you are saying is not in contrdiction to my statement above. But the devil is in the detail..you say that for small voltage a nerve membrane is ALMOST linear... so far ..so good.

I am pretty sure that when you do a PIM test (IP2 or IP3 style test ; in particular the IP3 test is extremely sensitive wrt nonlinearities) on nerve membranes you will get some signal....would you agree that nerve membranes most likely represent a less linear linear resistor than copper or some other metal?

Maybe the best representative of what both of you are saying is an electrolyte capacitor. It does have a rectifying term (if modelled properly) and all the electrochemical shebang that with it.

In the early days of broadcasting there was a period

between the coherer and the crystal detector, when electrolytical

rectifiers were used. Some comments on such devices can

be found if you search for Schlömilchzelle, Schloemilch, Fessenden.

Regards,

Joachim

Wow, That is what I call an efficient way to get an answer. The question raised a debate which I interpret as an answer to the origial question: there is no clear consensus. Especially thank you to Pedro because you address what triggered my question - the 'Gildemeister theory'. In said paper AC nervestimulation is of rectification leading to a theory of AC stimulation as an efficient way of nerve stimulation. Ward 2004: "The AC frequency is important because the

nerve fibre membrane acts as a rectifier [25] so an AC

stimulus is able to push the nerve fibre closer to threshold

with each successive pulse in a burst. Membrane

threshold is reached when successive pulses result in

sufficient depolarization to produce an action potential." The fact is that - examining the reference and said answers above- the membrane is non linear and a very poor 'diode'. Mostly this is based upon small signal modelling. Therefore the assumption of rectification beeing a DOMINANT underlying phenomena seems to be a long shot. In conclusion, no experimental evidence has yet been presented.

just saw this post, and only scanned the replies

Here is my two cents which I think is relevant. Taught lots of this in my BME courses.

I think there are some suble semantic issues. Physiologists argued for a while about negative resistance. Of course the membrane can't have negative resistance BUT it can appear to via to "anomolous inductance" resulting from highly nonlinear current voltage relationships.

The Cole book is an excellent reference for this! Jack, Tsien is also g

reat and has a great figure explaining important difference between chord and slope conductance.

In my PhD dissertation I showed that the Hodgkin-Huxley nerveembrane equations exhibited a "resonance" frequency (70 Hz, I think) so that a given amplitude stimulus could elicit action potentials ONLY near this frequency. Never published. but I THINK I might have seen this somewhere, let me know if you want me to TRY to track it down. Who knows my dissertation is probably online now (1993 Univ Virginia)

In addition

It is easy to show that if you model the membrane as an RLC circuit (not just RC) its a second order ODE so depending on paramaters it can exhibit oscillations.

Hope this helps

Cheers

-Rick

Perhaps the inductance is a bit far fetched here. Relaxation oscillation is far more common everywhere in nature so there really is no need to seek inductance where it apparently is not.

Relaxation oscillations can be observed in every active system in nature. Cycles of El Nino, wild fires, contagious diseases, and many more. Unlike oscillations produced by RLC type oscillators, the relaxation oscillators are not accumulating energy in their cycling, actually they burn it. They exhibit fairly constant period, but wild spans of amplitude. So if you think a new cycle of, say, measles , have failed, look at the data in log scale, and you'll see a small bump right on a schedule. Unlike a relaxation oscillator a RLC type oscillator requires a minimum Q factor to maintain oscillation, and beyond that you do not have any oscillations.

This 70Hz phenomenon might just be it.

If the accent is on "AC frequency preferences of neurons", from a physicist point of view you can find a good explanation in:

Hutcheon and Yarom (2000) Resonance, oscillation and the intrinsic frequency preferences of neurons. Trends Neurosci. 23, 216–222.

or

Izhikevich et al. (2003) Bursts as a unit of neural information: selective communication via resonance. Trends Neurosci. 26, 161-167.

Dear Richard, if the membrane is acting as a diode, how can it oscillate? And how does it apply to the Gildemeister effect? Do you suppose that it resonates until the threshold for firing is reached?

P.S. FYI:negative resistance exists is just a active circuit.

it oscillates via the interaction of the resistance and anomolous inductance. One can lineartize the full equations like Hodkin-Huxley at any voltage and see how the full equations reduce to RLC circuit which is classic second order system (minimum order to show oscillations). I don't have Cole book handy, try to get your hands on it. I do have 1965 Cole paper in Physiol Rev. I was staying away from saying membrane acts like a diode although it does behave very differently as a function of voltage due to the nonlinearities. In cardiac there is a highly nonlinear rectifying current called Ik1.

Besides Cole's book, that I suggested in a previous answer, I think it would be interesting to look the last edition of the book "Physiology of membrane disorders" edited by ANDREOLI T.E., HOFFMAN Joseph F., FANESTIL, Darrell D., where you can read several chapters related with the subjects being discussed

I'm pretty certain that you will not be able to find any mechanism on cellular level that will even remotely behave as an inductance. Even if one exists it would support oscillation at THz range which is waaaay beyond this phenomenon.

How about relaxation oscillation due to ion transporters? Voltage gated oscillations by means of electroenzymes are already confirmed on plants. The relaxation oscillation model would fix all the problems here, and using only mechanisms at hand, not some exotic inductance that just can not be there.

Since the beginning of the discussion, many persons made many interesting comments, each one from his own point of view, but sometimes very far from electrophysiology, and at least from my point of view, very far from the point. Are you satisfied with all this, Rune?

You hit the nail Roberto. I was wondering if people were actually reading the original question. Actually it all started because I mistakenly thought I was asking the author.

Id say thats all folks.

So the simple answer is 'no'. For more detailed answers of what it really is, see the above and most importantly, the references suggested. Research is never simple!