Question: why do you use mice?

Martha Havenith answered on 15 Jun 2015:

Hey Paddy and Kelsey,
that’s a very important question, and before starting a project you usually spend quite a bit of time thinking through that decision. Generally, you always try to work with the ‘simplest’ animal you can in order to achieve the experiment you want to do. In my case, I want to know what changes when you pay attention to something in your visual field. Why do you suddenly see things faster and better? What does the brain do to make that happen? So I can’t work with flies or frogs because I wouldn’t know how to teach them to pay attention, but I wouldn’t want to work e.g. with monkeys, because that would be complete overkill, and they would probably be bored out of their mind doing the visual tasks I use in my experiments. Of course working with (volunteering! 🙂 ) humans would be best, but then putting electrodes in their brain is kind of a problem…
From the technical side, one main reason to use mice is that their genetic code is the one we have the best map of. Part of my work is to use a (harmless) virus to insert some new genes into neurons. Those genes make the neurons sensitive to light (so that we can activate the neurons by shining light on them). Getting that virus to do its job in the brain only really works with a few species whose genetic code we know well – mainly rats, mice and flies (though some people have tried doing this in other species too).