Question: how would your test benfit to our understanding of neuroscience of mammals?

Martha Havenith answered on 14 Jun 2015:

That’s a very interesting question… Let’s get the obvious (and pretty much useless) answer out of the way: Mice are mammals, therefore understanding their brain benefits our understanding of mammal neuroscience. I told you that bit would be useless. 🙂 Let’s get to the more interesting (and more lengthy) part:
The answer to your question depends on how similar you believe all mammal brains to be. If mouse brains functioned in a very different way from ours – or from any other mammals – obviously we’d have a hard time gaining any general knowledge from our studies. So, how similar are mammal brains? The truth is that we don’t know for sure, because we don’t really understand yet how the brain works in general. Here are some best guesses:
The basic way neurons communicate is most likely the same across a vast range of species (even beyond mammals – to fish, insects and so on). It’s a bit the same as with human languages: They may sound different, and you can’t speak them all, but the grammar of different languages follows some basic common rules.
For neurons, ‘messages’ are generally transmitted by action potentials, i.e. small electric currents that flow through a neuron and make it ‘spew out’ neurotransmitters (i.e. little messenger molecules), which are then taken up by the next neuron. You could say that these action potentials are the letters of the neuron language. But the way the action potentials work together to flow through a group of neurons and build up a coherent message is the real riddle, and the answer is likely to be the same across species. We know the overall number of action potentials changes the message, and the exact moment they arrive at receiving neurons matters as well. But that’s about as rough as saying ‘When humans talk to each other, it’s important how loud their voices are.’ The statement is not wrong, but it’s a pretty simple picture of the human language. If our studies help us understand the general rules of neuron communication better, we can almost certainly generalize that knowledge across mammals or even beyond.

Another important bit of insight actually comes from the differences between mice and other mammals. For example, our group just found out that, unlike humans, mice can do lots of pretty difficult visual tasks without using their cortex (so the ‘more evolved’ bit of brain that is usually associated with ‘thinking’). This makes sense when you remember that mice mostly go out at night, so they care about vision a lot less than us. They use vision to scan for owls that are flying overhead, but most of their understanding of the world comes from smell and touch (especially with their super-sensitive whiskers). Vision for them is probably the same as the sense of smell for us – we start paying attention to it when something interesting happens (e.g. you notice the smell of burning food), but most of the time we are mainly aware of other senses (vision in our case).
Comparing these differences gives us a first clue how mammal brains may deal with different sensory information: We use one or two senses to generate a constant ‘input stream’ of the world, and we are pretty good at passing information that’s less crucial to us down to subcortical (i.e. earlier evolved, more ‘hard-wired’) bits of brain.