Monday, January 27, 2014

Proteomics of fear!?!?

This one is super interesting, albeit a little creepy.  This new paper currently in press at MCP takes a look at the changes in proteome profiles in the mouse brain during a model called "context fear conditioning".

Before I go any further, this is what WikiPedia and Google images told me about this model:

This was the simplest illustration I could find in the time I allotted myself to write this during lunch.  Essentially, it's like the Pavlovian conditioning thing except when you play a sound, you zap a mouse with electricity.  You then find that the you scare the beejeesus out of the mouse every time you play the sound thereafter.  We had an electric fence around our little farm when I was a kid.  My brother and I often did experiments like this on our youngest brother.  He's still real jumpy, which is also a little scary since he carries a handgun for his job....but I digress!

I have to admit, I'm a little confused by the experimental design here from the animal standpoint.  In an nutshell, one group of mice were allowed to wander around in a new environment for 3 minutes and then zapped.  A second group were zapped as soon as they entered their new environment, then allowed to wander for 3 minutes.  I guess the first group now thinks that wandering is bad?  While the second sees the zap as a random act of violence and doesn't associate it with wandering?  They summarize the method, but reference 3 papers, none of which appear to be open access, so I'm going to need to be a little foggy on this one.

60 minutes after this little zap experiment, the heads of the mice are separated from their bodies (my least favorite thing I've EVER done for science!  Kudos to you guys with the fortitude to do that a lot), the brains are removed and subsectioned.

The hippocampus (memory) and cortex were subject to protein arrays, probing for 84 different proteins.  And you know what?  They found statistically significant shifts! It appears that the majority of these shifts are in phosphoproteins in the brain.  I'm unclear (never done protein arrays) if the phosphorylation alone is enough to change the results of the array, but nevertheless, this is nuts.

Again, I know I didn't fully get this paper.  I don't understand the psychological context in which the model is framed, nor do I understand why the specific mouse strain (a mouse model of down syndrome?) was employed and how this affects the layout here. I also totally skipped over the fact that a drug I've never heard of was injected into some mice, which I'm sure adds more to the paper.


The title of the paper is:  Protein profiles associated with context fear conditioning and their modulation by memantine

1 comment:

  1. When you do many experiments on the animals models to do the biological analysis, you will find many interesting things.