Rat chat

Every night, after the sun sets on Acme labs and the white-coated scientists leave, two white-coated rats start plotting.

Pinky and The Brain Intro by RoseEveleth

Thankfully for cartoon humanity, Brain’s plans always failed, often thanks to his bumbling friend Pinky (narf). Of course, in real labs, rats can’t actually talk to each other. Or can they?

I recently visited Alfredo Fontanini’s lab at SUNY Stony Brook to hear all about the work they’re doing on their rats. (You can listen to the full podcast of his menagerie of sounds here.) To do his work, Fontanini records all kinds of sounds. One of those sounds is rats talking.

We can’t normally hear what the rats are saying – they vocalize at frequencies way higher than our ears can pick up. The sounds you’ll hear in this blog are slowed down to eight percent of their original frequency, so we can hear them. But it turns out that when you listen, rats are actually pretty chatty.

Researchers can tell a lot about a rat’s emotional state from these super high-pitched calls. Distressed rats sound like this:

22kHz reduced to 8% by RoseEveleth

While happy rats sound like this:

50kHz reduced to 8% by RoseEveleth

A growing number of studies are trying to use these vocalizations as indications of pain or pleasure. So when a researcher gives the rat something good, like a treat, she expects to hear the happy sound. When there’s a loud noise or the scent of a predator researchers expect to hear the distressed rat.

Researchers can use these known responses to look for things that are more difficult to measure. The effectiveness of anti-depression drugs, for example, could be measured by a change in the kinds of calls the rats make. Since you can’t ask a rat how it’s feeling, these calls could be useful for gathering information about emotional states.

Fontanini thought they’d hear a lot more of that first sound – the distress call. Lab environments can be stressful, and their rats have electrodes implanted in their brains to measure brain activity, which can be uncomfortable, especially for animals just after the surgery. But they actually had a really hard time recording that one – which is a good thing for their rats. It does not, however, guarantee that they’re not secretly plotting to take over the world.

Bonus: Pinky and the Brain sing you a lesson on the parts of the brain.

Special thanks to Alfredo Fontanini and Agnes Bao for the recordings.