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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 one million visitors each month.

Today, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than 1 million visitors each month. The field of early embryology has grown to include the identification of the stem cell as not only critical to organogenesis in the embryo, but equally critical to organ function and repair in the adult human. The identification and understanding of genetic malfunction, inflammatory responses, and the progression in chronic disease, begins with a grounding in primary cellular and systemic functions manifested in the study of the early embryo.

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Pregnancy Timeline by SemestersLungs begin to produce surfactantImmune system beginningHead may position into pelvisFull TermPeriod of rapid brain growthWhite fat begins to be madeHead may position into pelvisWhite fat begins to be madeImmune system beginningBrain convolutions beginBrain convolutions beginFetal liver is producing blood cellsSensory 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 ON weeks 0 - 40 and follow along every 2 weeks of fetal development
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Home | Pregnancy Timeline | News Alerts |News Archive Apr 17, 2015

This study is the first showing that a woman's cocaine use during pregnancy was more
damaging in altering her infant's brain's function than other drugs she may have taken.





Newborn brain is altered by mom's use of cocaine

rsfMRI brain scans of 152 infants found disruptions in babys' brain connections in the amygdala-prefrontal network. This is the first study to measure brain signals in infants exposed to cocaine in-utero.

"To our knowledge, this study is the first to show that a woman's drug use during pregnancy alters the brain's functional organization in her newborn," said Wei Gao, PhD, assistant professor of radiology in the University of North Carolina School of Medicine.

The study was published April 8, 2015 issue of the Journal of Neuroscience.

"This study may inform new strategies aimed at early risk identification and intervention," said Karen M. Grewen PhD, Associate Professor of Psychiatry, Neurobiology and Psychology.

In the study, 152 infants were given rfunctional magnetic resonance imaging (rsfMRI) scans. Of these children, 45 had prenatal exposure to cocaine and 43 had prenatal exposure to drugs other than cocaine, while 64 had no known prenatal drug exposure. In both groups with prenatal drug exposure, alterations in their brain functional organization was found. However, the group with prenatal cocaine exposure had more brain alteration than babies exposed to other drugs.

Specifically, the amygdala's response to the prefrontal cortex was found altered in babies exposed prenatally to cocaine.

This amygdala to prefrontal cortex connection may explain why immediately after birth, some cocaine-exposed infants appear to be in great distress. They are jittery and suffer tremors, are irritable and sensitive to the mildest environmental stimulation. Their muscles are unusually stiff. Often, they cry a great deal and do not fall asleep easily, and once asleep are easily awakened. They are unable to calm themselves. At the other extreme, some infants sleep much of the time and appear to shut down as if to avoid environmental stimulation.

This indicates a potential failure or risk for failure, of the prefrontal cortex continuing to suppress amygdala responses. Disrupting this circuit may be what underlies the easily aroused and frequently irritable infant born addicted to cocaine.

Overall, using rsfMRI in infants may be pivotal in the search for biomarkers identifying risks and early intervention to help improve these babies' outcomes.

Prenatal drug exposure, particularly prenatal cocaine exposure (PCE), incurs great public and scientific interest because of its associated neurodevelopmental consequences. However, the neural underpinnings of PCE remain essentially uncharted, and existing studies in school-aged children and adolescents are confounded greatly by postnatal environmental factors. In this study, leveraging a large neonate sample (N = 152) and non-invasive resting-state functional magnetic resonance imaging, we compared human infants with PCE comorbid with other drugs (such as nicotine, alcohol, marijuana, and antidepressant) with infants with similar non-cocaine poly drug exposure and drug-free controls. We aimed to characterize the neural correlates of PCE based on functional connectivity measurements of the amygdala and insula at the earliest stage of development. Our results revealed common drug exposure-related connectivity disruptions within the amygdala–frontal, insula–frontal, and insula–sensorimotor circuits. Moreover, a cocaine-specific effect was detected within a subregion of the amygdala–frontal network. This pathway is thought to play an important role in arousal regulation, which has been shown to be irregular in PCE infants and adolescents. These novel results provide the earliest human-based functional delineations of the neural-developmental consequences of prenatal drug exposure and thus open a new window for the advancement of effective strategies aimed at early risk identification and intervention.

In addition to Gao and Grewen, authors of the study are Andrew Salzwedel, PhD and Weili Lin, PhD, from UNC, and Clement Vachet and Guido Gerig, PhD, both from the University of Utah.

The study was funded in part by National Institutes of Health grants R03 DA036645-01A1 to Wei Gao and Karen Grewen and P01DA022446 to Karen Grewen, both from the National Institute on Drug Abuse (NIDA).

Other useful links:

What are the effects of maternal cocaine use?
www.drugabuse.gov › Cocaine
National Institute on Drug Abuse

Effects of Cocaine Use on Prenatal Development
National Center for Biotechnology Information, U.S. National Library of Medicine

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