Navigation Links
Pregnant mice block out unwelcome admirers to protect their pups
Date:7/20/2008

Mouse mothers-to-be have a remarkable way to protect their unborn pups. Because the smell of a strange male's urine can cause miscarriage and reactivate the ovulatory cycle, pregnant mice prevent the action of such olfactory stimuli by blocking their smell. Researchers from the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, have now revealed the nature of this ability. A surge of the chemical signal dopamine in the main olfactory bulb - one of the key brain areas for olfactory perception creates a barrier for male odours, they report in the current issue of Nature Neuroscience.

Social odours, such as pheromones, influence many aspects of human and animal behaviour perhaps most widely known reproductive behaviour. For example, exposing a newly pregnant mouse to the smell of an alien male's urine prevents the implantation of her embryos into the uterus and brings her back into the ovulatory cycle. The scent affects pregnancy by inhibiting the release of the pregnancy hormone prolactin. This phenomenon is often called the Bruce effect and creates a mating opportunity for the alien male. It is also beneficial for the female because it avoids infanticide by the strange male after birth. After day 3 of pregnancy, however, the smell of an alien male's urine no longer affects pregnancy. At this stage the embryos have already been implanted into the uterus and loosing them would bear a high cost for the female.

Liliana Minichiello and her team at the EMBL Mouse Biology Unit now discovered the molecular mechanism that underpins this change in sensitivity to male odours.

"At day 3 of the pregnancy a chemical change occurs in the brain of the expectant mother that makes her unable to perceive male odours. This seems to mark a point of no return for the pregnancy," explains Minichiello.

Following coitus, a progressive surge of the chemical signal dopamine takes place in the main olfactory bulb, the most anterior part of the mouse brain that is dedicated to the processing of odours. The dopamine flood is triggered by the physical stimulation during mating and progressively impairs the perception and discrimination of social odours contained in male urine. Treating pregnant mice with chemicals that block the dopamine receptor D2 abolished the barrier effect, restored odour sensing and favoured pregnancy disruption.

The findings unexpectedly reveal the main olfactory bulb as a key control centre of social and reproductive behaviour. Previous research in this area had focussed almost exclusively on other brain circuits. The main olfactory bulb likely achieves its control through projections to the amygdala and the hypothalamus, those regions of the brain that regulate emotional and reproductive behaviour through the release of hormones.

Dopamine is also found in humans, where it is mostly known for its role as the brain's 'reward chemical' that plays crucial roles in addiction and neurological disorders like Parkinson's disease, but it is also found in the human olfactory bulb. It is unknown if a process similar to the phenomenon observed in mice takes place in pregnant women.

"As far as we know, human pregnancy is not affected by strange male odours, but it could help explain why many women report changes in olfaction during pregnancy," says Che Serguera, who carried out the research in Minichiello's lab.


'/>"/>

Contact: Anna-Lynn Wegener
wegener@embl.de
49-622-138-7452
European Molecular Biology Laboratory
Source:Eurekalert

Related biology news :

1. Too much or too little weight gain poses risks to pregnant mothers, babies
2. Extreme nausea and vomiting varies among pregnant women from different countries
3. Pregnant patients lose out in breast cancer treatment; a new approach is needed
4. Pregnant women at risk for unnecessary operations due to misdiagnosis of appendicitis
5. Humans unknowing midwives for pregnant moose
6. Researchers discover a gene that regulates and blocks ovulation
7. Anti-inflammatory drug blocks brain plaques
8. Scientists make chemical cousin of DNA for use as new nanotechnology building block
9. U-M ballast-free ship could cut costs while blocking aquatic invaders
10. Human hormone blocker found to help prevent obesity and diabetes: study
11. Drug aimed at 2 bioterror agents blocks live viral infection, Weill Cornell team reports
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/15/2016)... , June 15, 2016 ... report titled "Gesture Recognition Market by Application Market - Global Industry ... - 2024". According to the report, the  global gesture ... in 2015 and is estimated to grow at ... billion by 2024.  Increasing application of ...
(Date:6/2/2016)... The Department of Transport Management (DOTM) of ... project, for the , Supply and Delivery of ... Infrastructure , to Decatur , ... Management Solutions. Numerous renowned international vendors participated in the tendering ... selected for the most compliant and innovative solution. The contract ...
(Date:5/20/2016)... , May 20, 2016  VoiceIt is ... partnership with VoicePass. By working together, ... experience.  Because VoiceIt and VoicePass take slightly different ... engines increases both security and usability. ... excitement about this new partnership. "This ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and ... and the 6000i models are higher end machines that use the more unconventional z-dimension ... light beam from the bottom of the cuvette holder. , FireflySci has developed ...
(Date:6/23/2016)... 23, 2016 /PRNewswire/ - FACIT has announced the ... biotechnology company, Propellon Therapeutics Inc. ("Propellon" or ... of a portfolio of first-in-class WDR5 inhibitors for ... as WDR5 represent an exciting class of therapies, ... medicine for cancer patients. Substantial advances have been ...
(Date:6/23/2016)... , June, 23, 2016  The Biodesign Challenge (BDC), ... new ways to harness living systems and biotechnology, announced ... (MoMA) in New York City . ... participating students, showcased projects at MoMA,s Celeste Bartos Theater ... Antonelli , MoMA,s senior curator of architecture and design, ...
(Date:6/23/2016)... LOUISVILLE, Ky. , June 23, 2016 /PRNewswire/ ... from two Phase 1 clinical trials of its ... double-blind, placebo-controlled, single and multiple ascending dose studies ... and pharmacodynamics (PD) of subcutaneous injection in healthy ... APL-2 subcutaneously (SC) either as a single dose ...
Breaking Biology Technology: