Featured Research

from universities, journals, and other organizations

Discovery of mechanism by which sex hormone regulates aggressive behavior in male birds

Date:
January 29, 2014
Source:
Waseda University
Summary:
Researchers have discovered a hormonal mechanism for controlling aggressiveness in male birds. The team hope this may lead to a method of reducing aggressive behavior in humans.

The current research, in order to understand the mechanism of GnIH inhibiting aggressiveness, involved a series of experiments using quail, an aggressive species of bird, as a model.
Credit: Waseda University

A group led by Professor Kazuyoshi Tsutsui and Research Associate Takayoshi Ubuka, of the Waseda University Center for Advanced Biomedical Sciences, has discovered a hormonal mechanism for controlling aggressiveness in male birds.

Male aggressiveness has long been thought to depend on androgen, a male sex hormone produced in the testes. However, previous research suggested that a synthetic enzyme (aromatase) can convert androgen into female sex hormone (estrogen) in the brain and regulate male aggressiveness.

In 2000, Professor Tsutsui et al. discovered a new hypothalamic hormone (gonadotropin-inhibitory hormone, GnIH; a type of neuropeptide) in the brain which inhibits reproduction. Later, Ubuka et al. demonstrated that GnIH can inhibit aggressive behavior.

The current research, in order to understand the mechanism of GnIH inhibiting aggressiveness, involved a series of experiments using quail, an aggressive species of bird, as a model. When GnIH was injected into a male's brain, activity of aromatase was increased, and the quantity of estrogen in the brain was greatly increased.

Next, when highly concentrated estrogen was injected, aggressiveness of the male quail was greatly decreased. Further, it became clear that neurons which synthesize estrogen have the receptor for GnIH.

This research shows that GnIH acts on the neurons which synthesize estrogen, to greatly increase production of estrogen and greatly decrease aggressiveness in male quail. Hence it is thought that when GnIH causes an extreme increase in estrogen synthesis, this creates an excess of estrogen in the brain and curbs male aggressiveness.

This research has explained a mechanism of regulating aggressiveness. Abnormally high aggressiveness is a major cause of instability in human society. This research provides a model for explaining behavior of quail, an aggressive bird species, but future work, by looking for a similar mechanism in humans, may lead to a method for regulating spikes in aggressiveness in humans, and thereby contribute to peace and order in society.


Story Source:

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


Journal Reference:

  1. Takayoshi Ubuka, Shogo Haraguchi, Yasuko Tobari, Misato Narihiro, Kei Ishikawa, Takanori Hayashi, Nobuhiro Harada, Kazuyoshi Tsutsui. Hypothalamic inhibition of socio-sexual behaviour by increasing neuroestrogen synthesis. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4061

Cite This Page:

Waseda University. "Discovery of mechanism by which sex hormone regulates aggressive behavior in male birds." ScienceDaily. ScienceDaily, 29 January 2014. <www.sciencedaily.com/releases/2014/01/140129075417.htm>.
Waseda University. (2014, January 29). Discovery of mechanism by which sex hormone regulates aggressive behavior in male birds. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/01/140129075417.htm
Waseda University. "Discovery of mechanism by which sex hormone regulates aggressive behavior in male birds." ScienceDaily. www.sciencedaily.com/releases/2014/01/140129075417.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. 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:
from the past week

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