Featured Research

from universities, journals, and other organizations

Oxytocin Raises Aggression, Cuts Anxiety During Lactation; Similar Effects On Virgin Rats

Date:
July 18, 2005
Source:
American Physiological Society
Summary:
Maternal aggressive/protective behavior is recognized throughout mammalian species, especially during lactation. The same neurohypophyseal hormone, oxytocin, is responsible for both the physiological and behavioral changes, but the site of action is different. OT within the brain has marked behavioral impact, including reducing anxiety levels during lactation. Regensburg/Edinburgh University researchers directly inserted OT into the brain of virgin rats causing lower anxiety and increased social dominance. Also: A model to determine OT regulation at birth.

STEAMBOAT SPRINGS, Colorado (July 18, 2005) -- Maternal aggressive/protective behavior is recognized throughout mammalian species, especially during lactation. When hiking, we warn our kids not to approach bear cubs, or to get between a cub and the mother. While driving and you see a fawn, you know a doe can't be too far away and will run headlong to protect it.

The same neurohypophyseal (NH) hormone, oxytocin (OT), is responsible for both the physiological and behavioral changes, but the site of action is quite different. OT is released during parturition and in lactation not only from NH terminals into the bloodstream in order to support reproductive systems, but also within the brain, into the supraoptic nucleus (SON) and paraventricular nucleus (PVN), where it has marked behavioral impact.

OT release in the brain is involved with such reproductive events as "morphological plasticity, autoregulation of OT neuronal activity and promotion of maternal behavior, including maternal aggressive behavior to protect offspring," Inga D. Neumann of the University of Regensburg, Germany, notes. "Thus in lactating rats from a line bred for high-anxiety behavior, or HAB, OT release within both the central amygdala and the PVN was positively correlated with the level of maternal offensive behavior against an intruder." In addition, the lactating HAB dams display higher aggression and central OT release compared with a low-anxiety line.

Very importantly, along with the rise of maternal behavior during lactation, OT also reduces anxiety levels by regulating the responsiveness of the hypothalamic-pituitary-adrenal axis. "Getting aggressive is one thing, Neumann observes, "but if you need to attack a bigger animal, you also must lower your level of anxiety."

Next, Neumann and her research team tested what effect direct OT insertion into the brain of virgin female rats would have. They found that "driving up-regulation of OT receptor binding in the central amygdala, using adeno-associated viral vectors, reduced the level of anxiety and promoted social dominance behavior in virgin females."

* * *

A model to determine OT regulation at birth

Alison Douglas, from the University of Edinburgh, who collaborated with Neumann on the previous study, is presenting a paper at the same meeting. Douglas sought to understand "the physiological mechanisms of birth to explain perinatal clinical problems that mothers may have, such as preterm labor, which put mother and baby at risk." Specifically she and her team investigated the role of certain chemicals in the brain that control OT secretion and the birth process. They administered drugs "to target their action in the brain of rats while they were giving birth."

"Using this model, we can investigate the functions of various brain chemicals and the regulation of OT secretion which are involved in the physiological processes of reproduction," Douglas said. "Parallels with the central mechanisms controlling oxytocin neurons in lactation may also help explain problems of 'milk let-down', where the mother is unable to breast feed," Douglas added.

###

Neumann and Douglas are presenting at the American Physiological Society's 2005 Conference, "Neurohypophyseal Hormones: From Genomics and Physiology to Disease," and the latest developments toward clinical applications, July 16-20 in Steamboat Springs.

They also are participating in the symposium, "Central control of lactation," chaired by Bill Armstrong of the University of Tennessee School of Medicine, and Glenn Hatton, University of California, Riverside.

"Oxytocin release within the brain: physiological and behavioral consequences in lactation." Inga D. Neumann, Martin Waldherr, Daniela Beiderbeck and Oliver Bosch, Institute of Zoology, University of Regensburg, Germany; Alison J. Douglas, University of Edinburgh; Larry Young, Emory University. Funded by Volkswagen Foundation and DAAD (German academic exchange) (Neumann); NSF (Young), British Council (Douglas).

"Evaluation of the role of central noradrenaline in activating oxytocin neurons at parturition." Alison J. Douglas, Alex Gillies, Vicky Briam, Simone Meddle, Neuroendocrinology, Centre for Integrative Physiology, University of Edinburgh, Scotland. Funded by Wellcome Trust.


Story Source:

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


Cite This Page:

American Physiological Society. "Oxytocin Raises Aggression, Cuts Anxiety During Lactation; Similar Effects On Virgin Rats." ScienceDaily. ScienceDaily, 18 July 2005. <www.sciencedaily.com/releases/2005/07/050718062645.htm>.
American Physiological Society. (2005, July 18). Oxytocin Raises Aggression, Cuts Anxiety During Lactation; Similar Effects On Virgin Rats. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2005/07/050718062645.htm
American Physiological Society. "Oxytocin Raises Aggression, Cuts Anxiety During Lactation; Similar Effects On Virgin Rats." ScienceDaily. www.sciencedaily.com/releases/2005/07/050718062645.htm (accessed October 2, 2014).

Share This



More Plants & Animals News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
'Harvest Break' Endures in Maine Potato Fields

'Harvest Break' Endures in Maine Potato Fields

AP (Oct. 2, 2014) — Educators and farmers are clinging to a tradition aimed at giving farmers much-needed help in getting potatoes out of the fields and into storage before the ground freezes in the nation's northeast corner. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. 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

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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