Welcome to The Visible Embryo
Home-- -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- -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 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.

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!




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.


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
Google Search artcles published since 2007

Home | Pregnancy Timeline | News Alerts |News Archive Apr 24, 2015

Oxytocin was traced back to its unique receptor cells. There researchers found oxytocin
controls the volume of "social information" being processed by individual neurons.
Curbing so-called excitatory (inhibitory) signals
Image Credit: Adapted from image by Logan Parsons, Nature Magazine





How oxytocin makes a mom

The oxytocin hormone teaches mom's brain to respond to her baby's needs. Future research could lead to using oxytocin as treatment for social anxiety, post-traumatic stress disorder and perhaps other brain behavioral issues as well.

Neuroscientists at New York University, Langone Medical Center have discovered how the powerful brain hormone oxytocin acts on individual brain cells to prompt specific social behaviors. The findings are published in the journal Nature April 15, 2015.

Until now, oxytocin — sometimes called the "pleasure hormone" — has been known for its role in inducing sexual attraction and orgasm, and regulating breast feeding and promoting maternal-infant bonding. But precisely how was not known.

"Our findings redefine oxytocin as something completely different from a 'love drug,' but more as an amplifier and suppressor of neural signals in the brain.

"We found that oxytocin turns up the volume of social information processed in the brain. This suggests that it could one day be used to treat social anxiety, post-traumatic stress disorder, speech and language disorder, and even psychological issues from child abuse."

Robert Froemke PhD, Assistant Professor at New York University Langone, Skirball Institute of Biomolecular Medicine, and study senior investigator.

In mice, Dr. Froemke and his team mapped oxytocin back to unique receptor cells on the left side of the cortex. There they found that oxytocin controls the volume of "social information" being processed by individual neurons and curbing so-called excitatory (inhibitory) signals — the neurons immediately determinine how female mice with pups should respond to their cries for help and attention.

In separate experiments in female mice with no pups — and no experience with elevated oxytocin levels — adding extra oxytocin into their "virgin" brains led these mice to quickly recognize the barely audible distress calls of another mother's pups recently removed from their nest. These females quickly learned to fetch the pups, picking them up by the scruffs of their necks and returning them to the nest - all as if they were the pups' real mother.

This learned behavior became permanent, researchers say; the mice with no offspring continued to retrieve pups even when their oxytocin receptors were later blocked.

Key to the researchers' efforts to track oxytocin as it worked in individual brain cells, was the use of an antibody. Developed at NYU Langone, the antibody specifically binds to oxytocin-receptor proteins located on each neuron. The antibody allowed the cells to be seen under a microscope.

"It was remarkable to watch how adding oxytocin shifted animal behavior, as mice that didn't know how to perform a social task could suddenly do it perfectly."

Bianca Marlin PhD, lead study investigator and postdoctoral research fellow at New York University Langone

Oxytocin is important for social interactions and maternal behaviour. However, little is known about when, where and how oxytocin modulates neural circuits to improve social cognition. Here we show how oxytocin enables pup retrieval behaviour in female mice by enhancing auditory cortical pup call responses. Retrieval behaviour required the left but not right auditory cortex, was accelerated by oxytocin in the left auditory cortex, and oxytocin receptors were preferentially expressed in the left auditory cortex. Neural responses to pup calls were lateralized, with co-tuned and temporally precise excitatory and inhibitory responses in the left cortex of maternal but not pup-naive adults. Finally, pairing calls with oxytocin enhanced responses by balancing the magnitude and timing of inhibition with excitation. Our results describe fundamental synaptic mechanisms by which oxytocin increases the salience of acoustic social stimuli. Furthermore, oxytocin-induced plasticity provides a biological basis for lateralization of auditory cortical processing.

Other researchers involved in the study, conducted entirely at NYU Langone, were Mariela Mitre, BE; James D'amour, BSc; and Moses Chao, PhD, whose laboratory developed the oxytocin receptor antibody used to track hormone activity.

Funding support for the study was provided by the National Institute on Deafness and Other Communication Disorders and the National Institute of Mental Health, both members of the National Institutes of Health. Corresponding grant numbers are DC009635, DC12557, and T32 MH019524. Additional funding was provided by McKnight and Pew scholarships; Sloan and NYU-Whitehead research fellowships; and a Skirball Institute collaborative research award.

For more information, go to:

Return to top of page