Tag Archives: stress

Mice are stressed by men: why this discovery is good news for research

Little mouseRecent research has found that the presence of male scents can stress out male mice. And this is pretty significant, as it’s important that research studies are able to be replicated.  This will likely have an impact on behavioral studies going forward- and that’s a good thing!

It’s extremely important to minimize variables in research.  Animals in research settings are often the best tools at a researcher’s disposal, due to this very reason. Unlike human subjects, research animals are able to be monitored extremely carefully in order to understand exactly which variables are significant. By understanding the effects of male scents on male mice, researchers have more information at their disposal as they attempt to minimize variables in their research studies.

By recognizing the fact that the gender of the researcher can have an impact on research outcomes, hopefully fewer animals will be needed to give statistically significant results. It’s also likely that researchers may now be able to understand why certain studies can be difficult to replicate. It’s commendable that researchers at McGill University in Montreal were able to provide this information to the research community. Read more about it here:



Can fear be inherited?

Plenty of traits are passed down from one generation to the next. Eye color, hair color, height, body type- but did you know that offspring can also inherit a parent’s trauma?

Studies in the past have shown that women who have experienced trauma tend to have lower levels of the stress hormone cortisol. Children of these women also had lower cortisol levels. And it might be expected that if a mother has experienced trauma and is stressed, her kids would be stressed due to her own behavior.

But a new study shows that nature AND nurture both play a role in this- that traumatic experiences can be transferred to the offspring through sex cells! Male mice were trained to fear a particular odor. During the process, this learning changed neuronal organization in the mouse’s nose. Then, IVF was performed with sperm from these males. Both the first and second generation offspring had similar neuronal organization in their noses, and they feared the same odor that their fathers did!

This shows that information stored in the brain is somehow transferred to sperm cells. Researchers don’t know how yet… but they’re working on it!


Stress during pregnancy is bad for your baby, too!

iStock_000013924965XSmallThink that stress during pregnancy doesn’t affect your baby? Think again.

When a baby is born, the first bacteria that it receives is from the birth canal- and this bacteria is responsible for beginning the bacterial colonization in the baby’s digestive system.

Stress has been proven to cause changes in the bacteria in the mother’s birth canal. In mouse studies, it was found that stressed, pregnant mice not only produced more types of bacteria, but Lactobacillus, a common and helpful bacteria for babies’ gut colonization, was greatly reduced. After birth, it was also found that gene expression in the brain was negatively affected by a reduced amount of Lactobacillus- specifically, genes related to neuron grown and connections in the brain.

Understanding this could lead to helpful therapies for human patients. By discovering the most useful bacteria to begin gut colonization, doctors can give newborns a dose of this beneficial bacteria after birth- this would be particularly helpful for babies born via C-section (who do not travel through the birth canal) and babies born to mothers who were on antibiotics (further altering the types of bacteria present).

So for pregnant moms out there- take it easy! Less stress for you ultimately means a healthier, happier baby.

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