User:VarunS93/sandbox

Assignment 4: Diffs from initial article edits for Neurokinin B

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Assignment 4: Begin Writing in Sandbox- Article Outline

Introduction

Neurokinin B,NKB, belongs in the family of Tachykinin peptides. Neurokinin B is implicated in a variety of human functions and pathways such as those of Gonadotropin-releasing hormone secretion Additionally, NKB, is associated with pregnancy in females and maturation in young adults. Reproductive function is highly dependent on levels of not only Neurokinin B but also Kisspeptin. The first instances of study done to learn more about NKB came after it was found that high levels of the peptide may be implicated in a condition known as Pre-eclampsia during pregnancy. Neurokinin B along with Kisspeptin and Dynorphin together are found in the Arcuate Nucleus (ARC) known as the KNDy subpopulation. These cells are targeted by a large number of steroid hormones and work together to form a network that feeds back to GnRH pulse generator

Synthesis

Neurokinin b is found in humans as a ten-peptide chain (decapeptide) attached to an end of chain amide group. The peptide formula is as follows, H-Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2. Neurokinin b (NKB), is encoded by the TAC3 gene in humans and Tac2 in rodent species.. Neurokinin b is expressed along with the peptides Kisspeptin and dynorphin A in the neuronal cells of the arcuate nucleus.. Five exon segments in the TAC3 gene encode for the NKB precursor known as preprotachykinin B. Preprotachykinin B is in a later step proteolytically cleaved into the pro-peptide, proneurokinin B. Following another cleavage from proneurokinin B, the final product, Neurokinin B is produced.

Receptors

The main receptor Neurokinin B interacts with is the neurokinin 3 receptor (NK3R). The Neurokinin 3 receptor is a part of a larger family of G-protein coupled receptors in which all tachykinin proteins bind. While Neurokinin B has the ability to bind to other Neurokinin receptors, the highest affinity lies in that of the NK3R receptor group. Much like the Neurokinin B peptide the NK3R receptor it binds to is encoded within five exons of the TACR3 gene in humans and the Tacr3 gene in mice and other rodents. High concentrations of the NK3R receptor are found in both the Central Nervous System and the spinal cord. Additional NK3R receptors have also been found in various other places in the body including: uterus, mesenteric vein, gut neurons, and placenta.. In addition, Neurokinin b has also been found to co-localize certain gonadal steroid hormone receptors. These include the estrogen receptor (ERα), Progesterone receptor (PR) and androgen receptor. It has been found that co-localization of the NKB neurons near these receptors is at a much higher concentration than even that of other peptides and chemicals. The Kisspeptin, Neurokinin b, and Dynorphin cell groups are found to be co-localized to more than 95% of all of the aforementioned receptors in the arcuate nucleus.

Role in Humans

During the Ovarian cycle GnRH secretion along with that of leutenizing hormone (LH) is highly regulated by a negative feedback system in with Neurokinin b along with its sister peptides the KNDy cell bodies play a role in. The NK3R receptor group when activated with a synthetic agonist of NKB, senktide, has been shown to stimuulate the secretion of leutenizing hormone. In addition, it seems NKB plays a larger role in females than in males. It has been found that in brain of females, the arcuate nucleus contains twice as many connections to NKB neurons than males.

Role in release of Gonadotropin-Releasing Hormone

Mutations or defects in the TAC3 or TAC3R gene can lead to steroidal feedback problems in the GnRH pulse generator loop causing GnRH to be understimulated leading to hypogonadism . During a review of neurokinin b along with its sister peptides, kisspeptin and dynorphin, it was found in sheep that that these KNDy cell groups (Kisspeptin, Neurokinin b, Dynorphin), are in direct contact with the GnRH neuronal bodies in both the pre optic Area and the mediobasal hypothalamus. Researchers found this to be consistent among species including humans. Due to the high percentage of co-localization found with Neurokinin b cell bodies and receptor groups it is suggested that Neurokinin b along with kisspeptin and dynorphin play a role in the release of GnRH . These findings are important since GnRH release plays such a huge role in regulating hormonal control in the bodies of humans.

References

• Role of Neurokinin B and Reproductive Neuroendocrinology
• Neurokinin B and the hypothalmic regulation of reproduction
• Current and Future applications of GnRH, Kisspeptin, and NKB analogues
• Tachykinin: Recent developments and novel roles in health and disease
• Neuropeptide co-expression in hypothalamic kisspeptin neurons of laboratory animals and the human
• Synthesis of Neurokinin B Analogs and Their Activities as Agonists and Antagonists
• A role for neurokinin B in pulsatile GNRH secretion in the ewe
• Profile of neurokinin B concentrations in maternal and cord blood in normal pregnancy
• Interactions between kisspeptins and Neurokinin b
• Minireview: KNDy

Initial Article Assessments

A Good Article is

• Well-Written
• Verifiable with no original research
• Broad in its coverage
• Neutral
• Stable
• Illustrated, if possible, by images

First Article Assessment, Neurokinin B

Well-Written

• The Article on Neurokinin B is currently a stub article. The article only has a small introductory paragraph. It needs many additional subsections added to it. Ideas right now for additional subsections are adding to the introduction, how it is synthesized, where and what it is used for, receptors it binds too, effect it has in humans and so on.

Verifiable

• Already I have found a few journal articles relating to Neurokinin B and its use in puberty and pregnancy. How it is an essential peptide hormone for development. A reference article will be linked at the end of the assessment. I do think I can find adequate research to make the Neurokinin B page on Wikipedia better.

Broad In Coverage

• No coverage yet to speak of. Very brief introduction, needs work and many subsections added to become a broad topic.

Neutral

• Article editing will take a neutral perspective when it starts, so far the introduction added does seem neutral

Stable Seems stable, needs addition of further research and information.

Images

• May be able to use certain images to get points across, only image thus far is of the molecular structure. Possible images can be added.

Overview

• Overall the article needs a lot of work but I think the challenge of making this article better will be a good thing in the long run. I look forward to working on this article as this is my first choice for edit.

Reference Article on Neurokinin B

Second Article Assessment,Fimbria of hippocampus

Well-Written

• Again this is a stub article and is in need of much expansion to be ready to post. The general introduction does not give nearly enough information as an introduction. Structure and relations sections are sparse with no citations. Additional sections are needed.

Verifiable

• There are no citations for information currently. When more information is added it will need to be verified by secondary sources. Information on structure, function, relations and interactions with other parts of the brain.

Broad in Coverage

• As it is now the article is not broad, it has very few sections. The level of writing is somewhat accessible but could be made easier to read. Additional sections mentioned above need to be added.

Neutral

• Article does seem neutral, not really a topic once can be biased on so I foresee it being easy to stay neutral in this article if It is the one that I Edit.

Stable

• Seems stable enough there have been no major edits in some time.

Illustrated

• The page currently does have good images of brain structure. I think these images will be useful in providing a clear and concise article.

Overview

• This is my second choice for article edit after Neurokinin B. I think this article also needs a lot of work to make it acceptable. However, it may be harder to find relevant information in journal articles and secondary sources to make it acceptable to be published to wikipedia

Reference Article on Frimbria Experiment

Article Contributions/Talk Page Additions

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Practice Week 2

Week 2 Assignment Practice Edit

The Very First Sentence!

Micheal Jordan was one of the greatest basketball players of our generation, winning 6 NBA championships.

Image Addition