From Embryology

Lab Attendance

Lab 1 --Z3414515 (talk) 12:46, 6 August 2014 (EST)

Lab 2 --Z3414515 (talk) 11:14, 13 August 2014 (EST)

Lab 3 --Z3414515 (talk) 11:07, 20 August 2014 (EST)

Lab 4 --Z3414515 (talk) 11:14, 27 August 2014 (EST)

Lab 5 --Z3414515 (talk) 11:13, 3 September 2014 (EST)

Lab 6 --Z3414515 (talk) 11:17, 10 September 2014 (EST)

Lab 7 --Z3414515 (talk) 11:23, 17 September 2014 (EST)

Lab 8 --Z3414515 (talk) 11:09, 24 September 2014 (EST)

Lab 9 --Z3414515 (talk) 11:34, 8 October 2014 (EST)

Lab 10 --Z3414515 (talk) 12:09, 15 October 2014 (EST)

Lab 11 --Z3414515 (talk) 12:43, 22 October 2014 (EST)

Lab 12 --Z3414515 (talk) 11:09, 29 October 2014 (EST)




B N La Du Pharmacogenetics: defective enzymes in relation to reactions to drugs. Annu. Rev. Med.: 1972, 23;453-68 PubMed 4118885

My Type in a Group


A Teamworker is the oil between the cogs that keeps the machine that is the team running smoothly. They are good listeners and diplomats, talented at smoothing over conflicts and helping parties understand one other without becoming confrontational. Since the role can be a low-profile one, the beneficial effect of a Teamworker can go unnoticed and unappreciated until they are absent, when the team begins to argue, and small but important things cease to happen. Because of an unwillingness to take sides, a Teamworker may not be able to take decisive action when it is needed.

Lecture Reviews

Lecture 1

Course introduction for embryology as well as the history of embryologists and how the diagrams of embryo changed through time as more advance technology was available. Guidelines to the course was mentioned as well as the assessments and type of work expected for this course.

Lecture 2

In the fertilization lecture the most interesting concept for me was the polar bodies and the sry gene. Every other concepts such as gametes, mitosis, meiosis and fertilization was familiar. Polar bodies and the sry gene was a completely new idea for me. Meiosis 1 releases first polar body and meiosis 2 releases the second polar body. Sometimes meiosis 1 releases first and third polar bodies.

Individual Assessments

Lab 1

Reference: Pmid25089626

Elo Madissoon, Virpi Töhönen, Liselotte Vesterlund, Shintaro Katayama, Per Unneberg, Jose Inzunza, Outi Hovatta, Juha Kere Differences in gene expression between mouse and human for dynamically regulated genes in early embryo. PLoS ONE: 2014, 9(8);e102949 PubMed 25089626

Method summary

Microarray Analysis

Raw data on Affymetrix GeneChip HGU133 were obtained from the ArrayExpress for human preimplantation embryos. The invariant set normalisation method was used and via using the Li-Wong method, the expression values were extracted from PM-values. The arrays were normalised independently and Li-Wong method was applied to all normalised arrays to get a summary of the expression measurements. Using Bayesian approach, differential expression between the consecutive development stages was analysed.

Embryo Collection

FVB/N mice were kept for 12 hours under light/dark cycle and were fed regularly. A Pregnant Mare’s Serum (5 IU) was injected into a 4-7 weeks old female. After 44 hours a human chorionic gonadotropin (5 IU) injection was given. The females then mated with the FVB/N strain studs (males). 19-21 hours later the females were sacrificed and the oviducts were collected. Oocytes were collected. The embryos were then cultured in KSOM medium.

Gene expression analysis

Extraction of RNA from mouse unfertilised oocytes using Arcturus PicoPure RNA isolation kit was done. Agilent Bioanalyser was used to measure the RNA quality and concentration. One embryo yielded 128 pg of total RNA on average. For each final protocol, three biological replicas of all the stages were collected.

TaqMan Array Cards analysis

RQ Manager version 1.2.2 (Applied Biosystems) were used to analyse Ct values. Hprt1 and Psmb6 were the endogenous controls which were used for normalisation.

Expression analysis from public sequencing dataset

Gene Expression Omnibus database was used to obtain the normalised RPKM values for human and mouse pre-implantation stages. The p-values were calculated for the pairs i.e. oocytes and 4-cell blastomeres and etc. The p-values below 0.05 were significant. In human and mouse, the average values for each stage between embryos in the same biological stages were calculated.

Result summary

Analysis of two independent human pre-implantation microarray datasets were done in order to define the genes with consistent gene expression profiles between embryo stages. The probes which had significant changes in both datasets were considered for further analysis. Probes in the “Up-down” cluster were up regulated whereas the probes in “Down” cluster were down regulated. Genes were selected from each cluster “Up”, Up-down” and “Down” for analysis of expression profile of mouse pre-implantation embryo by qPCR. A gene was included if its ortholog was found in any of the following samples in MGI: oocyte, unfertilized oocyte, fertilized oocyte, 2-cell embryo, 4-cell embryo, 8-cell embryo, 16-cell embryo, blastocyst. In the mouse, 55 genes with orthologs were selected for gene expression profiling. Also expression patterns of the selected genes in the mouse were studied. The maternal gene expression profile was seen to be shared in more than half of the mouse orthologs for genes “Up” and “Up-down” clusters. All the PRAME and most SSX, MAGEA and GAGE family members in human microarray were of “up-down” cluster. However, in the pre-implantation human embryo, the selected families’ genes had dynamic expression profiles.

Reference: Pmid25071849

Chunjuan Shen, Defeng Shu, Xiaojie Zhao, Ying Gao Comparison of clinical outcomes between fresh embryo transfers and frozen-thawed embryo transfers. Iran J Reprod Med: 2014, 12(6);409-14 PubMed 25071849

Method summary

This study was performed in Assisted Reproduction of Wuhan Union Hospital from January 2012 to December 2012. A total of 1891 cycles were used which contained 1150 fresh embryo transfers and 741 frozen-thawed embryo transfers. Cleavage-stage or blastocyst-stage was composed in 1150 women. Also 741 women were divided into cleavage-stage or cleavage-stage extended blastocyst culture or blastocyst-stage transfer. A GnRH agonist protocol was used in all the cycles. An injection of 10000 units of HCG was given to two or more follicles when they reached 18mm in diameter and then 34-36 hours later an ovum pick up was performed. After OPU, 4-6 hours later in vitro fertilisation was performed. The assessment for the embryo was based on the rate of development and morphology. All the good embryos were cryopreserved through vitrification. The number of implantations was observed as the number of sacs. Using the SPSS software, all the statistical calculations were performed.

Result summary

Clinical pregnancy rates for patients less than 35 years of age:

  • Fresh cleavage-stage embryo transfers: 52.7%
  • Fresh blastocyst transfers: 35.88%
  • Frozen-thawed cleavage-stage embryo transfers: 35.29%
  • Post thaw cleavage-stage extended blastocyst culture transfers: 47.75%
  • Frozen-thawed blastocyst transfers: 59.8%

Clinical pregnancy rates for patients more than 35 years of age:

  • Fresh cleavage-stage embryo transfers: 41.24%
  • Fresh blastocyst transfers: 26.92%
  • Frozen-thawed cleavage-stage embryo transfers: 11.32%
  • Post thaw cleavage-stage extended blastocyst culture transfers: 46.15%
  • Frozen-thawed blastocyst transfers: 55.8%

--Mark Hill These are very good paper summaries. (5/5)

Lab 2

E18.5 developing kidney expressing Pygo1 and Pygo2.jpg

E18.5 developing kidney expressing Pygo1 and Pygo2

Expression patterns of Pygo1 and Pygo2 proteins in the cortex of E18.5 kidney was determined using immunofluorescence. The location of both Pygo1 and Pygo2 were in the nucleus with the colour red. Both genes are expressed widely where in all the components of the developing kidney, a signal is detected. However their were high levels of stromal cell compartment(arrows). Original magnification x200

--Mark Hill (talk) 16:14, 21 August 2014 (EST) You have not explained in the file information or on this current page what Pygo1 and Pygo2 actually are? The correct information was associated with the image summary box, you do not need to repeat copyright and student template here. Images when used in your project will though include a reference link. (4/5)


Kristopher R Schwab, Larry T Patterson, Heather A Hartman, Ni Song, Richard A Lang, Xinhua Lin, S Steven Potter Pygo1 and Pygo2 roles in Wnt signaling in mammalian kidney development. BMC Biol.: 2007, 5;15 PubMed 17425782

© 2007 Schwab et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Note - This image was originally uploaded as part of an undergraduate science student project and may contain inaccuracies in either description or acknowledgements. Students have been advised in writing concerning the reuse of content and may accidentally have misunderstood the original terms of use. If image reuse on this non-commercial educational site infringes your existing copyright, please contact the site editor for immediate removal.

Lab 3

These are only the tip of the ice burg journal articles but further details will be mentioned later throughout this course as my path comes closer to its destination.

Yiwei Zong, Ben Z Stanger Molecular mechanisms of liver and bile duct development. Wiley Interdiscip Rev Dev Biol: 2012, 1(5);643-55 PubMed 23799566

Ian J Jacobs, Wei-Yao Ku, Jianwen Que Genetic and cellular mechanisms regulating anterior foregut and esophageal development. Dev. Biol.: 2012, 369(1);54-64 PubMed 22750256

Donghun Shin, Satdarshan Pal Singh Monga Cellular and molecular basis of liver development. Compr Physiol: 2013, 3(2);799-815 PubMed 23720330

--Mark Hill These are relevant articles, but you have not identified your project sub-section or explained in a sentence why you have selected these references (4/5).

Lab 4

1. Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings.

Therapeutic effect of human umbilical cord-derived mesenchymal stem cells in rat severe acute pancreatitis.

A technique used called flow cytometry illustrated that expressions of CD45, CD34, CD11b, CD19 and HLA-DR were lacking in MSCs derived from umbilical cord. However high expressions of CD44, CD73, CD90 and CD105 were observed. MSCs have the capability of osteogenesis, adipogenesis and chondrogenesis which was observed from the experiment of induction differentiation.

In control group, there were no edema, bleeding, inflammatory cells and necrosis in the pancreatic lobules at different times. Pancreatic edema was immediately observed after surgery in SAP group. Expansion of alveolar system, infiltration of inflammatory cells and parenchymal bleeding was noticed one day after surgery. Pancreatic parenchymal necrosis weakened three days after the surgery. The merging of necrotic area was seen five days after the surgery followed by the observation of tubular complexes. In SAP+MSCs group, over time the pathological changes improved and small amount of fibrous tissue were observed. Pathological scores for SAP were higher than those of the control group with regards to pancreatic parenchymal bleeding and nercrosis, pancreatic edema and infiltration of inflammatory cells.

After MSCs transplantation, apoptosis of pancreatic acinar cells reduced. In SAP group, large numbers of apoptosis cells in pancreas were noted. After MSCs transplantation, the apoptosis cells reduced in numbers since day 3. In SAP+MSCs group the number of apoptosis cells were lower than those in the SAP group on days 3 and 5.


Hong-Bo Meng, Jian Gong, Bo Zhou, Jie Hua, Le Yao, Zhen-Shun Song Therapeutic effect of human umbilical cord-derived mesenchymal stem cells in rat severe acute pancreatitis. Int J Clin Exp Pathol: 2013, 6(12);2703-12 PubMed 24294357

2. There are a number of developmental vascular "shunts" present in the embryo, that are closed postnatally. Identify these shunts and their anatomical location.

There are three vascular “shunts” present in the embryo. These are:

•Foramen Ovale: an opening that allows blood to flow from right atrium to the left atrium. This opening is located in the interatrial septum. There is a valve that is associated with this opening during the fetal period to prevent back flow of blood. This shunt closes when the blood pressure in the atria increases due to the newborn beginning to breathe.

•Ductus Arteriosus: is a short, muscular vessel which connects the pulmonary trunk and the aorta. Majority of the blood pumping into the pulmonary trunk from the right ventricle is therefore diverted into the aorta. Thus only enough blood reaches the fetal lungs to maintain the developing lung tissue. The pressure within the lungs drops dramatically as the newborn takes the first breath thus expanding both the lungs and pulmonary vessels. The smooth muscles in the wall of the ductus arteriosus constrict as the amount of oxygen increases hence sealing off the passage.

•Ductus Venosus: a temporary blood vessel that originates from the umbilical vein this bypasses the fetal liver and goes directly to the fetal heart.

--Mark Hill Stem cell paper is good review. The shunts are correct. (5/5)

Lab 5

Oesophagus Stenosis

Oesophageal stenosis is the narrowing of the oesophagus which usually occurs in the distal third. The oesophagus needs recanlization at the end of the embryonic phase to be complete. Oesophagus stenosis is when this recanalization is incomplete hence creating a significantly narrow lumen. This occurs during the eight week of human embryologic development. Oesophageal stenosis may also occur due to lack of blood supply to the affected area or the lack of development of the blood supply to the affected area. Usually the oesophagus lengthens but when the mishap of recanalization happens, it results in shortened oesophagus which then leads to the stomach being displaced superiorly through the oesophageal hiatus.


Eva Serrao, Alexandra Santos, Ana Gaivao, Ana Tavares, Sergio Ferreira Congenital esophageal stenosis: a rare case of dysphagia. J Radiol Case Rep: 2010, 4(6);8-14 PubMed 22470735



--Mark Hill Good summary of oesophageal stenosis and your sources are suitable for this topic. (5/5)

Lab 7

1. Identify and write a brief description of the findings of a recent research paper on development of one of the endocrine organs covered in today's practical.

One of the findings was on cell cycle regulation. Genetic material is copied is S phase and then divides into two daughter cell which is M phase. Cell cycle is regulated by checkpoint mechanisms which are very crucial in order to maintain a normal regulation. Length of cell cycle varies significantly. During the development of the pituitary gland, proliferation progenitors exit from the cell cycle are marked by the Cdkn1c and Ccne. The intermediate lob is frequently affected which contains rudimentary in humans. Most pituitary adenomas are benign and sporadic though familiar types do exist.

Shannon W Davis, Buffy S Ellsworth, María Inés Peréz Millan, Peter Gergics, Vanessa Schade, Nastaran Foyouzi, Michelle L Brinkmeier, Amanda H Mortensen, Sally A Camper Pituitary gland development and disease: from stem cell to hormone production. Curr. Top. Dev. Biol.: 2013, 106;1-47 PubMed 24290346

2. Identify the embryonic layers and tissues that contribute to the developing teeth.

The layers are vestibular lamina, distal lamina and these connect the developing tooth bud to the mouth’s epithelial layer. Also the enamel is separated into four layers which are outermost consisting of dentin, outer enamel epithelium, inner enamel epithelium and stratum intermedium. The tissues of teeth are hard tissues which include enamel and dentin, mineralised tissue, fused tissue, gingiva, pulpal tissue and soft tissues.

Weibo Zhang, Ivy P Ahluwalia, Pamela C Yelick Three dimensional dental epithelial-mesenchymal constructs of predetermined size and shape for tooth regeneration. Biomaterials: 2010, 31(31);7995-8003 PubMed 20682455

Xiao-Feng Huang, Yang Chai Molecular regulatory mechanism of tooth root development. Int J Oral Sci: 2012, 4(4);177-81 PubMed 23222990

--Mark Hill Your article summary does not make very much sense and you have not identified the embryonic origins of the tooth. (2/5)

Lab 8

1. Provide a brief time course and overview of embryonic development of either the human testis or ovary. (2-3 paragraphs)

Migration of mesonephric cells into the developing gonad and their proliferation appears to follow a well defined pattern.

Simultaneous occurrence of three specific events characterize the formation of ovigerous cord. First is the basal lamina material patches increasing which become apparent at the outer margins of oogonia and pre-granulosa cell complexes. Second is the isolation of oogonia from each other by pre-granulosa cells developing cytoplasmic extensions. Third and final is the increase infiltration of medullary stroma/rete cells between cortical complexes. The end results consist of clusters of oogonia and pre-granulosa cells which form the cords and these are isolated from the ovarian stroma by a basal lamina. The development of ovigerous cords differ in species with delayed meiosis. In humans, the ovigerous cords are not clearly defined. The presence of membrane enclosed clusters of somatic and germ cells in all mammalian fetal ovaries, are supported by evidence however the timing and the development may vary due to interspecies. As the basal lamina seperates the ovigerous cords which contain the pre-granulosa cells and oocytes from ovarian stroma, the ovigerous cords are opened to the surface of the ovary. The presence of isolated or small clusters of large cells in the ovarian medulla has been reported to consist throughout the period of cord and follicle development.

Development of cells within the ovigerous cords are based on three events which are initiation of germ cell meiosis, germ cell apoptosis and follicle formation. In humans, production of retinoic acid by ovarian is required for the meiosis to initiate. Retinoic acid is the key player in the initiation of meiosis. In humans, the development of meiosis and follicle progresses from inner and outer regions of the cortex. Germ cell proliferation rate decreases as the rate of germ cell death increases.

Peter Smith, Dagmar Wilhelm, Raymond J Rodgers Development of mammalian ovary. J. Endocrinol.: 2014, 221(3);R145-61 PubMed 24741072

Jing Xu, Min Xu, Marcelo P Bernuci, Thomas E Fisher, Lonnie D Shea, Teresa K Woodruff, Mary B Zelinski, Richard L Stouffer Primate follicular development and oocyte maturation in vitro. Adv. Exp. Med. Biol.: 2013, 761;43-67 PubMed 24097381

2. Include an image from the historic genital embryology section of the online notes in your description.

Transverse section of the ovary of a fox embryo

--Mark Hill The historic image is fine. The summary though does not clearly explain embryonic development of the ovary. (3/5)

Lab 9

Group 1

  • The structure of this page looks good regarding the text and image ratio.
  • Stages of lung development table was very effective for me to grasp the contents and understand it effectively. However providing an image would aid in grasping the contents effectfully.
  • Under the recent findings section, most of the information is relevant though you should consider the biochemical aspect of it too.
  • Current models need more researching. Try including more journal articles for current models maybe.
  • Under historic findings, more detail is needed for the fetal lung development. Try to obtain more relevant articles on fetal lung development and integrate the information with your current information.
  • Abnormalities are described well and are detailed so WELL DONE!
  • Good use of images which makes it engaging and interesting. Although some images lack captions and few images are missing copyright.
  • Try to include in text citations and put together all the references in the end of the page.
  • Just fix up the references and in text citations also mention your sections of the page in the introduction and that’s it.
  • LOOKS REALLY GOOD SO FAR just needs to fix few minor things.

Group 2

  • Very nice introduction. Keeps the reader engaged and outlines what the page is about specifically.
  • Historic findings have been untouched but do not worry I think you still have 1-2 weeks to complete this project. Try using pubmed and also it will be helpful to looks at Mark’s (course coordinator/convenor) historical textbooks/journal articles on his page.
  • Try having in text citations for the timeline. Also try making a table instead of dot points as well as use images if possible. Also try including a little more information in the timeline as this can give the reader a greater idea of what to expect.
  • Try including the years of when the current findings were discovered. Also try to have some information on the molecular signals which drive the development of renal in fetus.
  • The abnormalities section is well researched and well organised though I suggest putting the references in the end of the page as a bulk.
  • Well use of images throughout the page. All the images were related to the topic and were very well put together in the text.
  • I insist for you to put all the references in one place.
  • Finally just fix few minor things and add information to the historic section then you will be done. Overall well done as the page is well organised and is not missing much in terms of contents.

Group 4

  • Great progression on the table in text citation for it is missing. Also in the table for week 5 you have bullet points and for weeks 1-7 you have a different type of bullet point. Try keeping it consistent.
  • The diagram used to illustrate the genital development of different genders is very good and effective.
  • Current research and models section needs more pictures to help aid with the information. Under current models section, the hand drawn image is very good and effective in portraying the overview. Also in the current research and model section, try using more than one reference.
  • Current findings section is currently empty but that’s ok as you still might have 1-2 weeks to finish the project.
  • Historic findings needs more images as it seems like a big bulk of text. However it is very well researched.
  • Abnormalities needs more pictures as it seems like a bulk of text. I suggest obtaining a picture for each abnormality you talk about if possible. This aids the readers’ understanding of that specific abnormality. Also ‘pictures say a thousand words’ so it would be great if you can include pictures.
  • All hand drawn images are great and clear to read and understand.
  • Your references from other sections need to be in the end of the page in a bulk.

Group 5

  • Much more information on introduction is needed maybe. Also in text citations is needed.
  • EXCELLENT job on the overview development section. The table and the images are great especially. Great use to information and the corresponding images. One suggestion though, put in text citations.
  • Try to avoid repetitions as in the overview “this page” is repeated and in the table “a study” is repeated. Try being specific to which study you are referring to.
  • Well balance of text and images in the development overview section. In text citations are needed and all the references would look better in the end of the page in a bulk.
  • For your first research findings maybe obtain an image/s to aid the information.
  • Historic findings section is just a bulk of text. No images can be seen so if possible I suggest you add images to this section. Although it is VERY WELL researched.
  • VERY WELL DONE with the abnormalities section as each abnormality is well explained and has an image to accompany it.
  • Try not to use a lot of pictures and references from the Embryology website.
  • Over all this page is good but a lot of in text citation needs to be done and the references need to be in the end of the page in a bulk.

Group 6

  • The introduction section is blank so I suggest you start on it as soon as possible.
  • I like how you have organised the sections in terms of each gland.
  • Pineal gland section requires in text citations and more information with the aid of an image. Spelling error for abnormalities.
  • Hypothalamus section needs more information and images. Good idea to use a table but it is incomplete. In text citations are needed throughout.
  • Pituitary gland section only has the timeline and references. It needs much more information and images with in text citations.
  • Thyroid section is a bit better but still is missing little information.
  • Parathyroid gland has a very good image and the information is well presented. Once again in text citations are needed.
  • Thymus section only has little information so work more on this.
  • Pancreas by far is a much better section compared to others as it consists of an image, table and a timeline. In text citation are missing.
  • Adrenal gland section is missing a little information and an image that’s all. Also in text citation is missing.
  • Gonad development section is well presented just add images to it.
  • Placenta section just has references. You need to start researching information on this.
  • Associated abnormalities section just has an incomplete table.
  • The page could use a bit more uniformity. Throughout the page, two different spellings are used for fetal (fetal and foetal). Try keeping the context consistent.
  • Overall I suggest you start researching more for your project as A LOT of work may be needed to be done. In text citation is crucial as you have noticed by my constant repetition for it. Recent findings and historic sections are missing. I suggest researching on pubmed under “(gland name) historic/research findings”. All the references will look better and more professional if it was in the end of the page in a bulk. There are some really good information and images on your page. If possible try adding hand drawn images too. You may only have 1-2 weeks to complete this project but I believe you can do it so good luck!

Group 7

  • Introduction is well informed and written. Maybe write a bit more about what the page is about rather than just a background on the central nervous system. I suggest maybe putting up an image to aid the text. In text citations are missing.
  • Development during fetal period has great images to aid the information written so well done. Although I suggest not using bullet points a lot.
  • Brain development section has a very good table and an image.
  • Spinal cord development section needs more information.
  • Meninges development section is empty so research needs to be done as soon as possible.
  • Current models and findings section just has references so do start to write on what those research articles say.
  • Current research is well informed but images will help aid the information. Future research is blank which needs to be filled up with information.
  • Abnormalities section is quite good as the image and information relate to each other and the images help aid the information. A bit incomplete towards the end which you should write up on.
  • Overall, some of the images are a bit too complex so maybe try hand drawing some images in a simplified manner. All the references would look more professional and neat if it was at the end of the page in a bulk. Also historic findings section is missing so suggest you add that if possible. Good so far just missing bits and pieces of information which I am sure you can write up on within a week. Good luck!

Group 8

  • “Making Gains” is pretty funny but offcourse irrelevant to this project.
  • Your timeline needs a lot of work done as it is missing copious amounts of information.
  • Background embryonic development section is well detailed though it lacks images to aid the information. Also molecular and cellular regulation of fetal myogenesis section is the same; it is well informed but lacks images.
  • Much more is needed on tendon development, second and third trimester muscular development, neonatal, mechanisms/structure of muscle fibres and abnormalities.
  • Over all very good in text citations for the development (top) section. References from the background section should be at the bottom of the page with other references. The page mostly looks like a bulk of writing so include images where possible. A LOT more work is needed but I understand your situation as your group only has 2 members now so do as much as you can and GOOD LUCK!

--Mark Hill Some of your reviews are accurate while others need some more critical analysis of the project work. (8/10)

Lab 10

Identify a recent research paper on sensory development (not hearing) and write a brief summary (several paragraphs) of the research methods and findings. Include at the end a link to the relevant wiki sensory notes page.

All procedures were approved by the Ethics Commission of the Faculty of Medicine of the University of Coimbra in this study. Written consent was obtained from participants older than 18 years old. Only one eye was evaluated under monocular conditions in a dark room.

A total of 123 participants were considered for the intermediate spatial/null temporal frequency channel. For low spatial/null temporal frequency channel, a total of 135 participants were used. All participants were volunteers. All participants were examined via a complete neuro-ophthalmological examination. This exam included best corrected visual acuity (VA) which was obtained by Snellen chart, ocular tension, slit lamp biomicroscopy and fundus examination. All participants were right handed, had normal or corrected to normal visual acuity and were naive to the true purpose of the examinations being performed.

For intermediate spatial/null temporal frequency channel, achromatic contrast sensitivity was measured. The stimuli were static vertical gratings with spatial frequency of 3.5 cpd and were displayed on a 21-in. The stimulus, size and locations were all tested within the visual field. Psychophysical thresholds were obtained using an adaptive logarithmic staircase strategy. The staircases were run for a total of four reversals which was measured in decibels. In another task, detection targets in multiple locations of visual fields were used as stimuli. The subjects’ responses were recorded with millisecond resolution.

For low spatial/null temporal frequency channel the stimuli were sinusoidal vertical gratings with low spatial frequency. Testing with or without ramp does not change the spatial pattern of CS asymmetry results.

For both intermediate and low spatial/null temporal frequency channel, the results were via the examination of the anisotropy of contrast sensitivity between hemifields in development cohorts. Analysis of global patterns of left/right visual hemifield asymmetry were done using intermediate spatial frequency/static stimuli.

The overall results illustrated that interhemispheric (left/right visual hemifield) asymmetries were present in the early life during childhood and adulthood, but only for the intermediate spatial frequency channel. The right hemisphere dominance which is recognised for high level visual processing, can also hold true concerning low level spatial vision. The left visual hemifield advantage was found to be from childhood to adulthood.


Maria Fatima Silva, Otília C d'Almeida, Bárbara Oliveiros, Catarina Mateus, Miguel Castelo-Branco Development and aging of visual hemifield asymmetries in contrast sensitivity. J Vis: 2014, 14(12); PubMed 25326605

--Mark Hill This is not a suitable article. (2/5)