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

14 March 2011 - Mousey Smells

Hey you know that stuff that was keeping me busy this weekend?  Well, it went from a guy who scared the crap out of it to a very loving, quiet, happy home, and is being dropped off there in the morning.  :)

Lately, that's pretty much what I do.

Oh yeah, and twittering might be lax between now and Wednesday evening thanks to a fresh bout of tests being launched on me during the period of time most students are using to drink their livers rotten catch up in their studies.  So I'm sorry...priorities, ya know.  Posting shall continue, though.



Today's story is aboot mouse noses.  Baby mouse noses.  Because nothing could be more adorable (unless you hate mice).

You might already know that much of how young mice recognize each other (well really, recognize any other mice) is by smell, but it turns out this isn't already set up before they are born.  It takes a little while for the neurons in their noses to mature enough to identify mom as mom, and siblings as siblings.  It's probably the olfactory marker protein (OMP) that causes this essential development to occur.

In normal mouse pups, the choice to nurse/snuggle with mom won out 78% over that of another lactating female, but in mouse pups with no OMP, they failed to make the distinction at all.  Cool, right?  I know not everyone is thinking "man, that is really useful information for when I have a litter of orphaned mouse pups and need to find an appropriate foster mother that won't eat them that they'll actively nurse from," but it is an important point of development for more than just mice.  I wasn't under the impression that human infants identified mom by smell, though, but I do know that smell is an extremely important influence on people of any age and, thanks to conditioning, is an excellent way to trigger memories.

...Maybe this is why mom's cooking is always best?

Or maybe it's just interesting.



See you guys tomorrow,
-Miss Mouse



References and Links:
Wiggly baby mouse nosies
http://www.physorg.com/news/2011-03-mouse-nose-nerve-cells-mature.html