Welcome to The Visible Embryo

Home- - -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- News Alerts -Contact

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!



Home

History

Bibliography

Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Alerts Archive

Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.
Content protected under a Creative Commons License.

No dirivative works may be made or used for commercial purposes.

Return To Top Of Page
Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal 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 HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
Google Search artcles published since 2007
 
Home--History--Bibliography- -Pregnancy Timeline- Prescription Drugs/Pregnancy- Pregnancy Calculator - Reproductive System- -News Alerts

February 1, 2012--------News Archive Return to: News Alerts

Deletion of the PTEN gene increases the length and
density of dendritic spines (shown in right panels).

WHO Child Growth Charts

What Is Your BMI?

       

PTEN Gene and Hearing Problems in Autism

Loss of the auditory stimulation function of the PTEN gene can be reverseded through treatment with an immunosuppressant drug currently on the market.

New research from Cold Spring Harbor Laboratory (CSHL) might help explain how a gene mutation found in some autistic individuals leads to difficulties in processing auditory cues.

The study has found that when a suspected autism gene called PTEN is deleted from auditory cortical neurons—the main workhorses of the brain’s sound-processing center—signals from local as well as long-distance sources are not strengthened beyond normal levels as they need to be. However, the study shows this effect can be blocked by a drug currently in use as an immunosuppressant.

“It’s long been hypothesized that autism spectrum disorders (ASDs) arise from a partial disruption of long-range connections in the brain during development,” explains Professor Tony Zador, who led the study. “Our finding that PTEN-deficient neurons receive stronger inputs suggests that one way this disruption can be caused is by signal enhancement.”

His team’s work appears in the Journal of Neuroscience on February 1, 2012.

Although ASDs could arise from mutations in any of dozens of candidate genes, a core triad of symptoms defines all cases: impaired language, impaired social interaction, and restricted and repetitive behaviors.

“The challenge therefore has been to understand how this diverse set of candidate genes and the pathways they control converge to cause the common signature of ASDs,” Zador says.

The auditory cortex, which plays a critical role in auditory attention and perception, forms functional connections with other critical brain areas. The neural network within the auditory cortex has therefore been a target of studies aimed at understanding how alterations in neural circuits contribute to dysfunction in ASDs.

Zador’s team focused for several reasons on the role of one suspected autism candidate gene, PTEN, on circuit alterations within the auditory cortex.

Well known for its role as an anti-cancer gene that powers down cell growth, proliferation and survival, this gene has also been linked to ASDs by a slew of studies in humans and mice. PTEN mutations have been found in autistic individuals with extreme macroencephaly – an increase in brain volume. PTEN loss in mice has been found to boost cell size and the number of neuronal connections in the brain.

To decipher the role of PTEN on the auditory cortex, Zador’s group selectively disrupted the function of the PTEN gene in a subset of neurons of the auditory cortex, while leaving the gene intact in neighboring neurons. The scientists then assessed the effect of the loss of PTEN on connectivity within the auditory cortex.

The rapid and robust increase in the strength of both long-range and local inputs observed following PTEN loss might be attributed to an increase scientists observed in the length and density of dendritic spines – the tiny, knob-like structures jutting out of a neuron that act like signal-receiving antennae.

However, these effects could be blocked by chemically negating the effect of PTEN loss. Zador’s group found that treating the PTEN-deficient mice for 10 days with the mTORC1-inhibitor rapamycin prevented an increase in dendritic spine number and signal strength.

While Zador is excited about this finding that suggests that "mTORC1 could be a good therapeutic target for some cases of PTEN-mediated brain disorders,” he is also keen to further pursue his team’s new evidence that cortical hyperconnectivity could be the “final pathway” by which diverse ASD genetic pathways lead to a single ASD phenotype.

“Using cortical connectivity as a paradigm for assessing ASD candidate genes could provide insights into the mechanisms of the disorders, and perhaps even give us clues to create new therapeutic strategies,” he states.

This work was supported by grants from the National Institutes of Health and Autism Speaks.

“"PTEN regulation of local and long-range connections in mouse auditory cortex" appears in the Journal of Neuroscience on February 1. The full citation: Qiaojie Xiong, Hysell V. Oviedo, Lloyd C. Trotman, and Anthony M. Zador. The paper can be downloaded at http://www.jneurosci.org/ using the doi: 10.1523/JNEUROSCI.4480-11.2012

Founded in 1890, Cold Spring Harbor Laboratory (CSHL) has shaped contemporary biomedical research and education with programs in cancer, neuroscience, plant biology and quantitative biology. CSHL is ranked number one in the world by Thomson Reuters for impact of its research in molecular biology and genetics. The Laboratory has been home to eight Nobel Prize winners. Today, CSHL's multidisciplinary scientific community is more than 350 scientists strong and its Meetings & Courses program hosts more than 11,000 scientists from around the world each year. Tens of thousands more benefit from the research, reviews, and ideas published in journals and books distributed internationally by CSHL Press. The Laboratory's education arm also includes a graduate school and programs for undergraduates as well as middle and high school students and teachers. CSHL is a private, not-for-profit institution on the north shore of Long Island. For more information, visit www.cshl.edu.

Original article: http://www.eurekalert.org/pub_releases/2012-01/cumc-rop013112.php