Featured Research

from universities, journals, and other organizations

Progesterone Regulates Male Behavior Toward Infants

Date:
February 26, 2003
Source:
Northwestern University
Summary:
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.

EVANSTON, Ill. -- 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.

Related Articles


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.


Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.


Cite This Page:

Northwestern University. "Progesterone Regulates Male Behavior Toward Infants." ScienceDaily. ScienceDaily, 26 February 2003. <www.sciencedaily.com/releases/2003/02/030226073325.htm>.
Northwestern University. (2003, February 26). Progesterone Regulates Male Behavior Toward Infants. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2003/02/030226073325.htm
Northwestern University. "Progesterone Regulates Male Behavior Toward Infants." ScienceDaily. www.sciencedaily.com/releases/2003/02/030226073325.htm (accessed October 26, 2014).

Share This



More Mind & Brain News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Academic Scandal Shocks UNC

Academic Scandal Shocks UNC

AP (Oct. 23, 2014) A scandal involving bogus classes and inflated grades at the University of North Carolina was bigger than previously reported, a new investigation found. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Working Mother Getaway: Beaches Turks & Caicos

Working Mother Getaway: Beaches Turks & Caicos

Working Mother (Oct. 22, 2014) Feast your eyes on this gorgeous family-friendly resort. Video provided by Working Mother
Powered by NewsLook.com
What Your Favorite Color Says About You

What Your Favorite Color Says About You

Buzz60 (Oct. 22, 2014) We all have one color we love to wear, and believe it or not, your color preference may reveal some of your character traits. In celebration of National Color Day, Krystin Goodwin (@kyrstingoodwin) highlights what your favorite colors may say about you. Video provided by Buzz60
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins