Printer Friendly

Discovery of mechanism by which sex hormone regulates aggressive behavior.

Hopes for a method of reducing aggressive behavior in humans

Tokyo, Jan 29, 2014 - (ACN Newswire) - 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 (see PLoS ONE 2012).

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.

This research is presented in the paper "Hypothalamic inhibition of socio-sexual behaviour by increasing neuroestrogen synthesis", published 16 Jan 2014 by Nature Communications.

Nature Communications online:

http://www.nature.com/ncomms/2014/140116/ncomms4061/full/ncomms4061.html

For more information:

Mr. Kazuyoshi Tsutsui, Ph.D., Professor

Laboratory of Integrative Brain Sciences, Department of Biology

Waseda University

Center for Advanced Biomedical Sciences (TWIns)

2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan

Phone: +81-3-5369-7311

Fax: +81-3-3355-0316

E-mail: k-tsutsui@waseda.jp

Press release by ResearchSEA on behalf of Waseda University, JAPAN.

Source: Waseda University

Copyright 2014 ACN Newswire. All rights reserved.
COPYRIGHT 2014 Japan Corporate News Network K.K.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2014 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:ACN Newswire
Geographic Code:9JAPA
Date:Jan 29, 2014
Words:425
Previous Article:SGX China Futures Traded a Record 22 million Contracts in 2013.
Next Article:Festival of Media Asia Pacific Reveals Awards Shortlist for 2014.
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters