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Welcome to The Visible Embryo, a comprehensive educational resource on human development from conception to birth.

The Visible Embryo provides visual references for changes in fetal development throughout pregnancy and can be navigated via fetal development or maternal changes.

The National Institutes of Child Health and Human Development awarded Phase I and Phase II Small Business Innovative Research Grants to develop The Visible Embryo. Initally designed to evaluate the internet as a teaching tool for first year medical students, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than ' million visitors each month.


WHO International Clinical Trials Registry Platform
The World Health Organization (WHO) has created a new Web site to help researchers, doctors and patients obtain reliable information on high-quality clinical trials. Now you can go to one website and search all registers to identify clinical trial research underway around the world!



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Pregnancy Timeline by SemestersFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresFemale Reproductive SystemEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterSecond TrimesterFirst TrimesterFertilizationDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
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June 10, 2011--------News Archive

Hormone Test Helps Predict Success In IVF
Women with high levels of the hormone AMH produced more eggs for in vitro fertilization (IVF) procedures, and were more likely to have pregnancies.

Fragile X Protein Acts as Toggle Switch in Brain Cells
Research shows how the protein missing in fragile X syndrome – the most common inherited form of intellectual disability – acts as a molecular toggle switch in brain cells.


June 9, 2011--------News Archive

Early Light Refines the Brain’s Vision Circuitry
Light and sight are connected from the beginning.

Molecule Shared by Nervous and Vascular Systems
IRCM researchers show that a key molecule of the vascular system is essential for the formation of neural circuits.


June 8, 2011--------News Archive

Fetal Exposure to BPA Changes Uterus in Primates
Oral intake of BPA altered expression of HOX and WNT genes which are critical for uterine development.

Pregnancy Weight Gain Risks Fat Baby, Child, Adult
Women who gain too much weight during pregnancy tend to have newborns with a high amount of body fat, regardless of the mother's weight before pregnancy.


June 7, 2011--------News Archive

Exposure to BPA Has Been Underestimated
New research results indicate BPA accumulates more rapidly within the body than previously thought.

Pregnant Women Can Prevent Excess Weight Gain with Simple Steps
Women who did not self-weigh gained an average of 15.2 pounds.


June 6, 2011--------News Archive

Programming Disease by Gender
Excess maternal stress can program adverse health effects through multiple generations, especially in boys.

Birth Control Pill for Men On the Horizon?
But to make the pill a reality, research needs to show that the compound is safe, effective – and reversible.

Finding How Pre-gut Cells Become Focused
Research has outlined exactly how specific cells in sea-urchin embryos become the endoderm, the domain that eventually forms the gut.

Found, Genetic Mutation Causing Excess Hair Growth
Scientists in Beijing, China, have discovered a chromosome mutation responsible for a very rare condition in which people grow excess hair all over their bodies.

WHO Child Growth Charts

After one of FMRP's microRNA partners was disrupted, the neuron on the right had a greater density of dendritic spines than the control on the left.
The fragile X protein, called FMRP, hooks up with a group of molecules called microRNAs to switch the production of other proteins on and off in response to chemical signals, scientists at Emory University School of Medicine have discovered.

The results appear in the June 10 issue of Molecular Cell.

“For learning and memory to take place, neurons need to be able to make new proteins on demand, at particular synapses in a localized way,” says senior author Gary Bassell PhD, professor of cell biology and neurology at Emory University School of Medicine. “It appears that FMRP has evolved to use microRNAs to control the synthesis of proteins at synapses.”

In fragile X syndrome, FMRP’s absence leads to overactive signaling and unregulated protein production at synapses, the junctions between brain cells where chemical communication occurs. This leads to structural changes at synapses and an impairment of cells’ ability to respond to chemical signals, which in turn interferes with learning and memory.

Muddashetty and Bassell focused on a particular protein called PSD-95, whose production they had previously discovered was regulated by FMRP – although they didn’t know how FMRP exerted its control. PSD-95 appears to have an important role in anchoring together signaling molecules at synapses, the parts of neurons directly involved in learning and memory. Mice lacking the gene for PSD-95 develop normally but have more difficulty learning the location of a hidden platform in a water maze, compared with normal mice.

“The changes at synapses seen in fragile X syndrome are probably not caused by the overproduction of a single protein,” Bassell says. “But we think that losing the ability to make PSD-95 on demand is an important component.”

In cultured neurons, Muddashetty studied part of the RNA molecule encoding PSD-95, which responds to excitement by the neurotransmitter glutamate. This way he could dissect which proteins and RNA molecules were needed. Interfering with a particular microRNA, called miR-125, could stop the PSD-95 RNA from responding to glutamate signaling and could even drive neurons to produce more protrusions at their synapses.

MicroRNAs are involved in a process called RNA interference, whose discovery earned the 2006 Nobel Prize in Medicine. RNA interference is a way that short RNA molecules (microRNAs) can silence a stretch of genetic code.

These tiny RNA molecules have become a widely used laboratory tool for shutting off a specific gene. When the RNA molecules are introduced into the cell, they are actually hijacking a machine inside the cell called RISC (RNA-induced silencing complex). MicroRNAs normally govern the activity of RISC, which can prevent a given gene from being translated from RNA into protein.

In a sense, FMRP is acting as a “RISC manager.” Together with microRNA, it clamps down on an RNA, preventing the synthesis of protein, until glutamate signals force them to loosen up. Thus, FMRP determines when the protein should be made at the synapses.

“Future work may uncover whether this is a general mechanism to guide specific miRNAs onto target mRNAs at synapses,” the authors write.

The finding illustrates how microRNAs are emerging as key players in neurological development and disease, Bassell says. Since a given microRNA can regulate hundreds of targets, one potential drug strategy for fragile X syndrome would be to aim at restoring microRNA function.

The research team included the first author, Ravi Muddashetty PhD, and contributing co-authors, Vijayalaxmi Nalavadi PhD, Christina Gross PhD, Xiaodi Yao, Oscar Laur PhD and Lei Xing PhD. This research was done in collaboration with Stephen Warren PhD, professor and chair of the Department of Human Genetics. The research was supported by the National Institutes of Health, the Fraxa Research Foundation and National Fragile X Foundation.

R.S. Muddashetty, V.C. Nalavadi, C. Gross, Xiaodi Yao, L. Xing, O. Laur, S.T. Warren; and G. Bassell. Reversible inhibition of PSD-95 mRNA translation by miR-125a, FMRP phosphorylation and mGluR signaling. Mol. Cell (2011).

The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service.

Original article: http://shared.web.emory.edu/whsc/news/releases/2011/06/fragile-x-protein-acts-as-toggle-switch-in-brain-cells.html