Anxious mice make lousy dads: study

Jun 13, 2012

Normally, male California mice are surprisingly doting fathers, but new research published in the journal Physiological and Biochemical Zoology suggests that high anxiety can turn these good dads bad.

Unlike most rodents, male and female California pair up for life with males providing extensive parental care, helping deliver the pups, lick them clean, and keep them warm during their first few weeks of life. Experienced fathers are so paternal that they'll even take care of pups that aren't theirs. "If we place a male California mouse in a test cage and present it with an unknown pup, experienced fathers will quickly start to lick and huddle with it," said Trynke de Jong, a post-doctoral researcher at University of California, Riverside.

Inexperienced males, on the other hand, aren't always so loving. "Virgin males show more variability," de Jong explained. "They may behave paternally, or they may ignore the pup, or even attack it. We want to understand what triggers these three in virgin males."

De Jong and her colleagues thought this variability might have something to do with social status. In other species—including another , Mongolian gerbils—dominant virgin males are more likely than subordinate ones to kill pups. Perhaps social status influences parenting in California mice as well.

To test this, de Jong and her colleagues paired up 12 virgin males in six enclosures, and performed several tests to see which was dominant. First was a food competition. "If a cornflake is dropped in the cage, the more dominant male will manage to eat most of it," de Jong said. The researchers also observed each mouse's urine marking. "Dominant males will make more, smaller, and more widespread marks than subordinate males," said de Jong

After determining the mightier mouse in each pair, the team tested parental behavior by introducing a pup. Contrary to the hypothesis, scores on the dominance tests did not predict whether a male licked or huddled up to the pup. However, the research did turn up signs that anxiety, not status, plays a role in paternal behavior.

Males who shied away from urinating the middle of a new enclosure—a behavioral signal that a mouse is anxious—were slower to approach a pup. Further tests showed that less paternal males had higher levels of the vasopressin in their brains. Vasopressin is a hormone that is strongly associated with stress and anxiety.

"Our findings support the theory that vasopressin may alter the expression of paternal behavior depending on the emotional state of the animal," de Jong said. She believes these results could shed light on the role of stress in paternal care in other mammals—including humans.

Explore further: Cats put sight over smell in finding food

More information: Trynke R. de Jong, Aniko Korosi, Breanna N. Harris, Juan Pablo Perea-Rodriguez, and Wendy Saltzman, "Individual Variation in Paternal Responses of Virgin Male California Mice (Peromyscus californicus): Behavioral and Physiological Correlates." Physiological and Biochemical Zoology 85:6 (November/December 2012, published online now www.jstor.org/stable/10.1086/665831).

Related Stories

Females decide whether ambitious males float or flounder

Jan 30, 2008

Aggression, testosterone and nepotism don’t necessarily help one climb the social ladder, but the support of a good female can, according to new research on the social habits of an unusual African species of fish.

Penis size does matter if you are a bank vole

Oct 05, 2011

(PhysOrg.com) -- While size may not matter when it comes to humans, a new study published in Behavioural Ecology and Sociobiology found that the width of the male bank vole’s penis plays a role in soc ...

Bullying alters brain chemistry, leads to anxiety

Mar 28, 2011

(PhysOrg.com) -- Being low mouse on the totem pole is tough on murine self-esteem. It turns out it has measurable effects on brain chemistry, too, according to recent experiments at Rockefeller University. ...

Striped mice -- the neighbors from hell

Jun 22, 2010

Fighting, paternity tests and infidelity. No, not a daytime talk show, but the results of new research examining why the fur will fly if a four-striped grass mouse (Rhabdomys pumilio) wanders into his neighbour's territory. Resear ...

Anti-social mice may reveal more about depression

Mar 01, 2011

(PhysOrg.com) -- For the first time, UC Davis psychology researchers have been able to produce a "social withdrawal" syndrome in female rodents. The development could yield new insights into the physical basis ...

Importance of sex-specific testing shown in anxiety study

Oct 15, 2008

An Australian study has flagged an important truth for the medical research community. Like their human counterparts, male and female mice are not only different, their respective genetic responses can often be the reverse ...

Recommended for you

Cats put sight over smell in finding food

3 hours ago

Cats may prefer to use their eyes rather than follow their nose when it comes to finding the location of food, according to new research by leading animal behaviourists.

Feds spot third baby orca born recently to imperiled pods

4 hours ago

(AP)—U.S. scientists following endangered killer whales from a research vessel have spotted a baby orca off the coast of Washington state, the third birth documented this winter but still leaving the population ...

Bumblebees make false memories too

6 hours ago

It's well known that our human memory can fail us. People can be forgetful, and they can sometimes also "remember" things incorrectly, with devastating consequences in the classroom, courtroom, and other ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

baudrunner
not rated yet Jun 13, 2012
..confirming why we use mice in lab experiments, because they are almost like humans in behaviour and response. Obviously, there is some need for research labs to continue to homogenize mouse brains lest the labs become overrun with the little critters. Knowing what they already know about lab mouse behaviour and response, was this experiment really necessary for research purposes? I think not.
Jeddy_Mctedder
1 / 5 (1) Jun 13, 2012
i love to anthropomophize mouse behavioral studies.

so from the gerbils and the mice, we see that hyper-dominant or hyper anxious fathers are bad fathers. .....surprising. :)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.