29 March 2011 - Bullied Mouse Braaaaiiiins

I reserve the right to skip blogging for the next few weeks if:

• I wind up getting that wrist surgery I desperately need
• There is not time for at least four hours of sleep
• I'm rushing through several weeks of material to pass the last couple of weeks of class I have left
• I'm out of town (a-freakin-gain)

Hilariously, that means I might not be blogging much.  But every morning that I can, I will!  Yaaaayscience.

No really, ya can't make this up.  I currently have enough obligations in my life to keep a small village busy and I'm searching for change in the couch to fill my gas tank (how do I manage to be in a different town one-two times a week when I work every single night?  Hey, overtime will cover it, right?  Right?  RIGHT??)

Enough of that.  Y'all have your busies, too, and that's why I do this thing!




Today's post is on mouse brains.


It seems like basic logic that a mouse who is bullied learns to be more cautious around new mice, but there's more to it than that.  Mice were placed in with bigger, meaner mice for ten minutes (I breed mice, and this makes me cringe to think about - they don't need that ten minutes to kill each other if they're serious!), then separated but left close enough to still induce stress.  They then tried placing the mice with larger, but nonthreatening (how do they figure...) mice and noted behavioral changes consistent with fear, anxiety, and cautiousness.  They then checked out the brain and noted that they had a markedly higher sensitivity to vasporessin, an important hormone associated with the behavior (and other behaviors, including in people).

Mice that were given vasopressin blockers showed less of the wary behavior when placed in with the nonthreatening mice.

You know, I am absolutely FOR using animals in labs.  I believe we have excellent standards in place by IACUC and have seen firsthand how strict the inspections are.  But man, the mouse breeder in me just really knows how serious male aggression in mice is.  They don't need ten minutes, man.  In an enclosure with little or no cover, they can rip each other right apart.  It's like cichlids.  Just, yipes.

What I'm REALLY curious about is how they tested with "non-threatening" mice.  One assumes, based on the territorial statement in the article, that the mice being tested are male.  Females can be aggressive but this is pretty rare and short-lived as they sort out a pecking order in the colony.  So if you're putting in nonthreatening mice to examine followup behaviors, how do you get a nonthreatening mouse?  It has to be male, or you have to take into account sexual hormones.  It has to be a nonfamiliar mouse or you have to take into account imprinting and familiarity, which can also incorporate hormones and scent.  So you have to have a completely new, male mouse.

Just how do you plan on getting new mouse not to attack?  Eh, I know there is a lot more going on than the summary shows, but I would LOVE to read the actual paper.  Alas, I have only access to the abstract.  :)






See you guys soon!
-Miss Mouse






References and Links:
Mouse Bullies (Physorg):
http://www.physorg.com/news/2011-03-bullying-brain-chemistry-anxiety.html

Mouse Bullies with Bigger Words (ScienceDirect):

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T0P-52C3K4S-2&_user=10&_coverDate=03%2F11%2F2011&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b963eecbd72b883ea4fa2181c97afa12&searchtype=a