Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Progesterone regulates male behavior toward infants


In an unexpected discovery, a team led by Northwestern University scientists has become the first to show that progesterone, a hormone usually associated with female reproduction and maternal behavior, plays a key role in regulating male aggression toward infants in mice. Testosterone, not progesterone, had been thought to be responsible.

The researchers found that the absence of progesterone’s actions reduced aggression while promoting positive paternal behavior. The findings, to be published online by the Proceedings of the National Academy of Sciences during the week of Feb. 24, suggest a new approach to studying an area of biology that has been poorly understood.

"We discovered that the hormone progesterone and its receptor are important in males, not just females," said Jon E. Levine, professor of neurobiology and physiology, who led the provocative study. "Paternal behavior may be based in the same biology as maternal behavior."

Like adult males of many other species, male mice rarely contribute to parental care and often attack or kill infants soon after birth. Although this hostile behavior had previously been attributed to testosterone, a correlation between testosterone and male behaviors directed at young has never been established. Seeking another explanation for the male behavior, Levine’s research team tested paternal behavior in progesterone receptor knockout mice. (These mice lack the gene that encodes progesterone receptors and thus the animals are not affected by the presence of progesterone.)

"In male knockout mice we noticed something quite startling," said Levine. "They behaved differently, and the most obvious changes were a complete lack of aggression toward infants and the emergence of active paternal care. These animals are terrific dads."

After breeding males of both the knockout and a control strain, the researchers found a complete absence of infanticide in the resulting litters born to knockout mice. Comparatively, 74 percent of the control mice committed infanticide. Additionally, knockout mice contributed significantly more paternal care than the controls by frequently contacting pups and retrieving them to nests.

In a separate experiment, the researchers used a drug to block the progesterone receptors in normal mice and found that these mice behaved like the knockout mice -- they were highly paternal.

Because, like the controls, the knockouts exhibited similar levels of aggression toward other adult males, the researchers surmised that the knockouts’ general level of aggression, a testosterone-dependent behavior, is not affected in these animals. These results suggest that progesterone, and not testosterone, may be key in specifically controlling infant-directed aggression in male mice.

"The same neuroendocrine mechanism may be important in other mammals, including humans, but further research is required," said Levine. "At least in the case of mice, this appears to be an important neurochemical switch that can increase paternal behavior and decrease aggressive behavior toward infants."

Other authors on the paper are Johanna S. Schneider (lead author), Marielle K. Stone and Teresa H. Horton, from Northwestern University; Katherine E. Wynne-Edwards, from Queens University, Kingston, Ontario; and John Lydon and Bert O’Malley, from Baylor College of Medicine, Houston.

The research was supported by the National Institute of Child Health and Human Development.

Megan Fellman | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute

nachricht 'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>