Talk:Haemodynamic response

Untitled

What is the source of this info?

HRF Picture

Can someone add this? http://commons.wikimedia.org/wiki/File:Hrf.svg

The file was added and a caption was inserted. thank you for the image suggestion. Liber.mark (talk) 02:52, 28 November 2012 (UTC)

HRF in SPM models

We could do with some reference to Statistical_parametric_mapping, since the HRF is key to smoothing the design matrix. Jddriessen 13:26, 6 April 2007 (UTC)

References

Added references and made small corrections. The part about astrocyte involvement seems to agree with the description in David J Rossi, Another BOLD role for astrocytes: coupling blood flow to neural activity, Nature Neuroscience 9, 159 - 161 (2006) http://www.nature.com/neuro/journal/v9/n2/full/nn0206-159.html Except "opening" mGluR, which was plain wrong - it's just binding. The role of nitric oxide synthase was confirmed by (among others) Bojana Stefanovic et al.; Functional uncoupling of hemodynamic from neuronal response by inhibition of neuronal nitric oxide synthase; Journal of Cerebral Blood Flow & Metabolism (2007) 27, 741–754. http://www.nature.com/jcbfm/journal/v27/n4/full/9600377a.html The rest is textbook stuff and can be found in Siesjo, Brain Energy Metabolism, Wiley 1978. Smocking 13:36, 22 May 2007 (UTC)

BI481 Project

This page will be continuously updated until mid-December 2012 as part of an Introduction to Neuroscience course at Boston College. Please be aware of large changes to this page during that time. Liber.mark (talk) 20:31, 12 November 2012 (UTC)

This article is comprehensive and makes the topic easy to understand, I enjoyed reading it. I did notice that there is a good description of pericytes, but is it necessary since there is a pericyte Wikipedia page? Also, at the end of the paragraph on pulmonary hypertension, maybe a few of the treatments of the disease could be included to show how this complication can be dealt with to provide a little more insight into its qualities. The "Clinical Use" section is well done; I found it very interesting to read (although I don't know if the question asking "How is this of clinical significance" is necessary). Lastly, if the picture has a little more explanation it might be more useful to someone reading the article. Nverghis (talk) 01:07, 18 November 2012 (UTC)

thank you for your feedback. We have edited out redundant pericyte information from the page and added a Treatment section for PAH. We removed the informal sentence that you indicated also. Lakkisn (talk) 03:04, 28 November 2012 (UTC)

The article is well written and the material is presented in a concise and effective manner. I immediately noticed the use of bullet points and they are not necessary. You should avoid using them and make a subtitle for each one instead if want to keep the two items separated in the article. I also noticed the picture that was used. I understand it somewhat, but it does not match with the article in any manner because the article does not describe any experiments that match it. If you can find an fMRI or PET scan image, that may be more applicable. Otherwise, you can find a graph that shows haemodynamic response to certain stimuli. The time format would be helpful if it was tied to explanation of what it was actually describing. I agree slightly with the review above regarding the pericytes. It would be better to hyperlink the term, but you should try to keep all necessary information that is relevant to your topic, such as the receptors involved in constriction and dilation. If you feel it is necessary to help further explain your topic, then it should be kept in, but general information should be relegated to a hyperlink to the pericyte page. For the Complications portion of the article, I believe you should choose a standard format for all the complications. You can singled out Alzheimer's and Ischemia, but none of the others. Is there a reason for this? If it is because Alzheimers and Ischemia decrease haemohynamic response, then there should be a distinction made with what the other complications do. This is mentioned in each complication, but in order to uniform grouping, a standard should be chosen. The content is very informative, but the format needs to be standardized. Once again, try to avoid using bullet points. Lastly is to try to keep to the article in the context of an encycopedia article, not a narrative. It was mentioned in the previous review, but "How is this of clinical significance" is unnecessary and wouldn't be foudn in a normal encyclopedia article. This is the only instance where I found it, but make sure to look through the article once more to make sure there are not any others. Overall, this is a very good article. Ian Kates (talk) 04:12, 19 November 2012 (UTC)

thanks for the ideas. The format for Complications was changed (subheadings were added), but we wanted to concisely focus on Alzheimer's and ischemia and that is why those were highlighted specifically. Those are the two most common disorders treated today and were the two that deserved our fullest attention. The subheadings under Mechanisms were made consistent. Liber.mark (talk) 02:51, 28 November 2012 (UTC)

I thought the article was very interesting and informative. It was thoroughly written, easy to follow and understand. Especially, I liked how the reference was well written under the standards of Wikipedia so that the reader can get access to the original referenced article easily.

I do have some suggestions which could help improving this article. Regarding formatting, as suggested in reviews above, more terms could be hyperlinked such as cerebral blood flow and fMRI, etc... and I also noticed that in the introduction, you could hyperlink "blood flow" instead of "blood". These are just minor grammatical issues that I have found: "in vitro" should be italicized under "astrocytes" section and in-citation should come after punctuation. And under "Functional magnetic resonance imaging" section, the term, "MR signaling", appears several times but this acronym, "MR" is never spelled out. Does it mean "magnetic resonance"?

As for content, I agree with the review above that it would be helpful if the image, "the canonical haemodynamic response function" is incorporated and explained in the text somewhere because I didn't really understand what the image supposed to mean. And in the introduction, where it says, "The intracerebral arterioles and capillaries are unlike arterioles and capillaries in that they do not readily allow substances to diffuse through them", it would be nice if latter arterioles and capillaries are specified more to prevent any confusion. I also have few suggestions for re-organization. I've noticed that under "Mechanism" section, the subtitles are not consistent in form. Some title was just cell types while others were cell types with their function/role. If you guys want to put emphasis on functional part of it as well, I would name the section as "Mechanism and function" and the sub-titles with both cell types and their role. (For example, astrocytes and constriction). Also, consider reorganizing "Complications" section into three parts, "acute coronary syndrome", "pulmonary arterial hypertension", and "neurodegenerative diseases". I think sub-sectioning this part would contribute more to make the article flow easily. This article would be informative even more if some current/future researches were provided at the end of the article. Lastly, I found the reference #3 article was not secondary sources because it is an original research article. To make the article more reliable, you guys might want to reconsider this reference. Kwakg (talk) 04:48, 19 November 2012 (UTC)

typos were corrected and hyperlinks were added, as you indicated. A descriptive caption was added to the Canonical hemodynamic response image. The Complications section was broken down into subsections, as you advised. Information from source 3 was obtained from the introduction to the article, rather than specific experimental primary information, so I feel it is reliable and should be included as a source for our information. thanks for your input. Liber.mark (talk) 02:51, 28 November 2012 (UTC)

This is a great article; it is extremely comprehensive and easy to read. I have a few suggestions:

Structurally, I think the second paragraph in the introduction would be better in a different section. It is definitely important to describe the vasculature/histology but not necessarily in the introduction. I think the first paragraph would suffice as an introduction. Also, I think the "Complications" section could be broken down into smaller sections. It is a big chunk of information, so subsections such as "Acute Coronary Syndromes," and "Pulmonary Hypertensions" might make the page easier to navigate.

In terms of content, I think the only bit that needs some revision is the PET scan. First, it is important to write out "Positron emission tomography". There are a few typos/grammatical errors, as well. Additionally, fluorodexoxyglucose is not a medicine tagged to glucose; radioactive fluorine is tagged to glucose and that compound itself is FDG.

Overall, though, great page! Very informative.

OliviaHall10 (talk) 06:50, 19 November 2012 (UTC)

edits were made to the PET section as you advised, and typos were corrected. Thanks for your comments.Liber.mark (talk) 02:51, 28 November 2012 (UTC)

Great work on the article overall! It covers a full range of aspects relating the topic, is concise, and contains a lot of good research.

First, I would recommend going through and proofreading for some grammatical errors, to point out a couple:

"Complications in this response arise in acute coronary syndromes, and pulmonary arterial hypertension." The comma before the and is not needed

"Treatment usually include aspirin, Clopidogrel, nitroglycerin, and if chest pain persists morphine" should be "includes"

Also, I agree with the other reviewers about the image. I think it could be useful if you better describe what is going on in the graph so that the readers can easily understand how it relates to the HR.

As for the introduction, this section should be a brief summary of the entire article and shouldn't include any information not discussed in the rest of the article (according to wikipedia standards.) Therefore, you may want to consider revising the introduction so that it is more of a general overview of all the parts of the article and move the discussion of vascular anatomy to another section, perhaps before you introduce the mechanisms of HR. You may also want to mention briefly in the introduction that the major nutrients that are delivered through blood flow are oxygen and glucose, as these nutrients are the basis for the discussion of HR through the rest of the article.

In the mechanisms introduction, you state "but the basic tenets of vascular constriction and dilation have been agreed upon by several studies." You may want to consider citing some of these studies. I agree with the other reviews that the article does need some standardization, including the subtitles in the mechanisms section. In order to have a more uniform structure, you may want to change the subtitles to just simply "astrocytes," "smooth muscle," and "pericytes."

As for the standardization of the complications section, I also agree that you need to make more clear subsections, because as it stands now there seems to be no reason why Alzheimer's and hypoxia are separated from the other complications. Also, in your discussion on ACS, you may want to make a more meaningful transition between the second and third paragraphs, because it is not immediately clear why you go directly into discussion of coagulation and sepsis after introducing ACS.

I also believe that the following section on PAH could use some editing: "PAH can be a severe disease, which may lead to decreased exercise tolerance, and ultimately heart failure. It involves vasoconstrictions of blood vessels connected to and within the lungs. As a result, the heart has a hard time pumping blood through the lungs, and the blood vessels eventually undergoes fibrosis. The increased workload on the heart causes hypertrophy of the right ventricle, which leads less blood being pump through the lungs and decreased blood to the left side of the heart. As a result of all of this, the left side of the heart has a hard time pumping a sufficient supply of oxygen to the rest of the body, which deteriorates the effect of the haemodynamic response. Impaired haemodynamic responses in turn diminish exercise capacity in patients with PAH. The severity of haemodynamic dysfunction during progressive exercise in PAH can be recorded using cardiopulmonary exercise testing (CPET), and/or impedance cardiography (ICG). Furthermore, there are no current cures for pulmonary arterial hypertension, but there are treatment options for patients with the disease to help prolong their survival and quality of life." This section includes a few grammatical problems with subject/verb agreement. Also, the discussion seems to be a little repetitive when it discusses heart failure. Additionally, because the paragraph describing PAH is already pretty lengthy, perhaps you could make a new paragraph break when you begin discussing recording for PAH and treatment for PAH.

I think the clinical use section is well-written and contains a lot of useful information. I have a few suggestions, though. In the introduction of this section, you introduce fMRI but do not mention PET scan. It seems that it would make more sense to mention both before going into detail of both in the two subsections. As mentioned by another review, you also may want to link to the fMRI wiki page. The voice in the fMRI also becomes more narrative in tone when you include "How is this of clinical significance?" and "To wrap it all together," so you may choose to revise this.

I hope these suggestions are helpful, and keep up the great work on this informative article!

Ellen.white4 (talk) 20:09, 19 November 2012 (UTC)

Typos were corrected and section headings were made consistent and revised as you suggested. Other revision ideas you added have been corrected and described in the page comments above. Thank you for your help! Lakkisn (talk) 03:04, 28 November 2012 (UTC)

Overall the article is nicely organized, easy to read, and the introduction summarized the topic very well. I do have some suggestions that might improve the readability of the article as well as one minor grammatical correction. Under the section “Mechanisms of haemodynamic response,” It makes more sense to have the sentence “Whether the vessels are constricted or dilated dictates the amount of oxygen and glucose that is able to reach the neuronal tissue” at the beginning of the section because it tells the reader what they need to know about why constriction and dilation is going to be discussed and how it affects HR, rather than stating “Precise mechanisms are still under investigation, but the basic tenets of vascular constriction and dilation have been agreed upon by several studies”. In addition, the sentence “Endothelial cells, smooth muscle, neurons, astrocytes, and pericytes work together in the brain order to maintain the BBB while still delivering nutrients to tissues and adjusting blood flow in the intracranial space to maintain homeostasis” This sentence was difficult to read, I believe that the word “inorder” was meant to be used rather than “order”. And lastly, the Alzheimer’s section is confusing to read and does not explain why and how amyloid plaques lead to a reduced HR, until the end of the paragraph and it is also repetitive. Perhaps some of the sentences could be moved around, such as the sentences towards the end that explain why the two proteins involved in amyloid beta determine whether the smooth muscle of blood vessels contract. These sentences would be better suited near the beginning of the section and would make for a more concise explanation rather than repeating amyloid buildup twice and not explaining the mechanism behind it.

Overall the article was easy to follow and very informative, I really enjoyed reading the clinical use section.Mellalisa (talk) 22:53, 19 November 2012 (UTC)

thank you for your suggestions regarding the Mechanisms section. Oxygen and glucose were added to the paragraph as you advised, and the sentence you recommended was added. It was a good edition to the section. The Alzheimer's section was also revised and the wording was made to be more clear. thanks again for your input!Liber.mark (talk) 02:51, 28 November 2012 (UTC)

Review

The only thing I have to say, which has been mentioned in previous posts is to watch out giving to much information on other subjects in your page. Your page should be focused exclusively on your own subject. If it relates to other projects then you can state that and say how, but you don't necessarily have to give the whole story on the other subject. AdamMJenks (talk) 15:06, 29 November 2012 (UTC)

thanks Adam. we've altered the sections to only give information relative to our topic-- in our previous edits, we definitely had delved into other wikipedia pages and strayed off topic. thanks again for your input! Liber.mark (talk) 02:41, 30 November 2012 (UTC)

Ambiguity in the article title

I understand that within brain research "haemodynamic response" of course means with respect to the brain. But is there a better title for this page so that someone finding this article at random would not think it was about the same topic as hemodynamics? Maybe "cerebrovascular hemodynamic response"? Or "hemodynamic response (neurobiology)"? Gccwang (talk) 05:01, 23 August 2014 (UTC)

I rather agree that there is a problem with determining the scope of this and other related pages, ie what information ought to be on which page, and making clear through the titles exactly what is covered by each. This is difficult because someone needs to review all the related pages and get a good idea of how best to structure them, and this is a technical subject where medics might be aware of shades of meaning not obvious to ordinary readers. In general, if this page is essentialy a sub-page of the more general hemodynamics page, dealing specifically with the brain, then this needs to be made clear and there ought to be a short summarising section within the Hemodynamics article linking this one. Other articles seem to be referencing this one in a purely general way without any implication it is about brain function.

There is a problem in having one article titled Haemodynamic Response, and another Hemodynamics....with different spellings of haem... We need to choose one! Sandpiper (talk) 08:29, 30 November 2015 (UTC)