Crocodile
© Pixabay
"Scientists put a crocodile into an MRI machine with classical music" may sound like somebody playing a game of science Mad Libs, but it's now officially a real experiment that real scientists have run.

And it's for a fairly interesting reason, too. Scientists always want to better understand our brains, which have evolved continuously over the ages as we branched out of past species and developed on our own. But to understand how our brains evolve, we'd need to look at an ancient brain, which isn't possible.

But in the rare case where this is a good thing, crocodiles are old apex predators who haven't needed to evolve much over millions of years, and their brains have seen minimal changes compared to other animals like birds and mammals. They share enough minor similarities with modern mammal and bird brains that researchers led by Felix Ströckens at Ruhr University Bochum, Germany, decided a functional look at crocodile brains is worth the effort.

So that's how Ströckens and his team ended up sticking a Nile crocodile into an fMRI machine (short for "functional magnetic resonance imaging"), the first time the device has been used on cold-blooded animals. This was not easy, for obvious reasons that involve manhandling a croc and less obvious reasons that involve keeping their body temperatures stable inside the machine.

Croc in MRI Scanner
© Felix Ströckens
A crocodile prepares to enter the MRI scanner.
Both problems were solved by sedating them/taping their snout shut and managing the heat emitted by the machine, and then the real fun started. Five young crocodiles were put in the machine and exposed to auditory and visual stimuli while their brains were scanned for BOLD (blood oxygenation level-dependent) signal changes.

These stimuli included flashing red and green lights and, more interestingly, the soothing sounds of Johann Sebastian Bach's "Brandenburg Concerto No.4" after playing simple chords at various intervals, to see whether the croc brains reacted differently when hearing simple and complex sounds.

Surprisingly, the crocodiles' brains did react differently when hearing classical music, as their brains lit up in a similar way to modern humans and birds, suggesting that animals have had the ability to respond to more complicated sounds for a very long time. According to CNET, Ströckens said the following:
Given that birds produce quite sophisticated 'music' on their own, one can assume that they have specialized brain areas to process complex sounds. But we did not expect that crocodiles have areas which look and seem to work so similar.
This doesn't mean that the crocodile could appreciate Bach like the modern human can (although even we don't always do that), but it can recognize that this is more than just a simple noise. And since crocs are so old, they've likely inherited this trait over countless generations of previous crocs.

And as another victory, Ströckens also proved that a cold-blooded animal can successfully handle an MRI scan. And he got out without a single crocodile bite. So that's something.