Talk:Mechanoreceptors and stochastic resonance

Nicely done paper overall. It could be split into two papers eventually, one on nechanoreceptors, the other on stochastic resonance in biology. The article needs a few more subheadings to guide the reader through the mass of info on mechanoreceptors. The figures also need captions.

In section 1.1, the word adapts appears, without definition. This is used a few more times, so either it should be briefly defined (decrease in firing rate following stimulus onset ...) or changed so that the word "adaptation" appears as a link to its definition in scholarpedia. Spindle muscle is confused with muscle spindle. Second paragraph the word "released" needs to be removed after "neurotransmitter".

Axoneme should be briefly defined, as well as integument and statocysts.

Section 1.2: The first reference to the tailfan is Fig.7. The paper might benefit from having that moved to Fig.3 right away. The current Figure 3 needs a description of solid and dashed lines.

Section 2.1: the double well SDE should be formated in line, on on its own, but not half of one and half of the other. Right below it, we should read: (the noise on top OF the waveFORM has been removed...The height of the sharp peak above the noise floor should be clarified: the "height" here equals top of peak minus noise floor.

Figure 5: tick mark labels are too small.

Threshold or non-dynamical SR should be numbered as 2.2. Just below, the word threshhold needs to get one "h" removed. Sub threshold should be one word. We should read: "...is flat as shown by the ..."

The SNR equation: Delta^2 should be D^2 in the exponential. We should read: "the enhancement is maximal at an optimal noise intensity".

Section 2.3: "The introduction of SR into biology was its first demonstration in any field other than physics (Douglass et al. 1993)": that is true on the experimental side, but it should be pointed out that this first experimental demonstration followed theoretical predictions in Longtin,Bulsara,Moss PRL91 and Bulsara, Jacobs, Zhou, Moss, Kiss JTB 91. Also the text first writes that the experiment used 10Hz stimulation, then mentions sharp peaks at about 48 Hz. There is an inconsistency here.

Review by Ward

Content is fine. I list only some comments (in addition to the above by another reviewer that appear above these, pretty much all of which I agree with) to help improve the article. I'm not sure about the level of the mechanoreceptor part of the article, however. In addition to the terms mentioned by the first reviewer, it contains many more quite technical terms that are not defined - e.g., sterocilium, kinocilium, nuclear bag, apical surface, voltage-gated channels, soma, neuromasts, ... - to list them all and define them all would be way too tedious. But I'm not sure a reader not well-versed in neurobiology would get much from this article. It reads more like a high-level summary (and a good one) for a neurobiologist audience. I do think that the authors could look over the mechanoreceptor part of the article and try to make it more accessible to people untrained in neurobiology. The SR part of the article is much clearer I think and is accessible to most scientists and well-read lay people. I would probably also have a lot of small rewritings if I were to redo the article Wiki-style but as the authors want traditional review I'll only comment on whatever I think are important improvements that could be made. I have done a few small corrections to typos, grammar, and spacing of equations, etc.

1. The first paragraph should define both "mechanoreceptor" and "stochastic resonance" as these are the topics of the article (according to the guidelines for a good Scholarpedia article). The first sentences in the respective sections 1 and 2 are good in this respect and could/should be inserted in the first paragraph before the material that is there.

2. Section 1.1, end of paragraph 1: I'm not sure there is agreement on the role of Golgi tendon organs in generating the feeling of "self" - at the least a reference to the argument needs to be provided.

3. In the discussion of the gating-spring model in para 2 of section 1.1 I'm surprised there is no mention of the work by Hudspeth on frog auditory and balance systems, who is I believe the first person to propose and confirm this model (I could be wrong - this is the first I was aware of and Hudspeth has produced a continuous series of excellent article on this model, it's associated molecular motors, etc. - his Science article in 1985 summarizes the early work and there are later reviews).

4. End of para 2 of section 1.1: some taste transduction systems (salt, acid) rely on simple depolarization of the receptor cell membrane by ions passing through channels to increase intracellular Ca2+ and cause release of neurotransmitter, whereas others rely on receptors in the cell membrane and require a second messenger system to do this.

5. Para 3 of section 1.1: not all ciliary bundles in the cochlei of vertebrates (at least higher ones) contact the tectorial membrane - only the steroecilia of the outer hair cells do so - the shearing force on the kino and stereocilia of the inner hair cells is caused by their being swept though the viscous endolymph (see Raftenberg, 1990, JASA, 78, 2606-).

6. Section 2.2, equation for SNR: the choice of notation for the bandwidth of the noise as $$f_0$$ is unfortunate, as the same symbol was used for the signal frequency peak in the power spectrum in the previous sentence. Also, the equation as written does not contain the $$D^{-2}$$ in the exponent - I guess the $$\Delta^2$$ there should be replaced by $$D^2$$.

Response to authors' emendations by reviewer Ward

The authors have made some changes but a couple of things have not been addressed that I think should be. First, I still think that the introductory sentences need to be augmented in line with the Scholarpedia policy of providing a definition of the article topic at the beginning. Second, no response was made to several of my requests - some are not critical but I do think numbers 5 and 6 (the latter also noted by the other reviewer) are critical. If the authors stand by their usage here I would appreciate a response in this reviews section saying why.