Insane in the Chromatophores from Backyard Brains on Vimeo. The folks at Backyard Brains, a DIY-neurobiology project, made these pigment-producing cells in a dead squid pulse to the base beats of Cypress Hill's "Insane in the Brain." Go watch that thing right now. Done? Wowed? Prepare to be more wowed: They did it by exploiting the fact that electrical current is key to both the actions of cells and the playing of mp3s. These pigmented cells, called chromatophores, are surrounded by muscle cells, and it's by flexing these muscles that the squid reveals its colorful spots. By hooked up the nerve that sends the flexing orders to the wire of a set of earbuds, they got these amazing results. Here's their description of how music made the muscles pulse:
An iPod plays music by converting digital music to a small current that it sends to tiny magnets in the earbuds. The magnets are connected to cones that vibrate and produce sound. Since this is the same electrical current that neurons use to communicate, we cut off the ear buds and instead placed the wire into the fin nerve. When the iPod sends bass frequencies (<100Hz) the axons in the nerves have enough charge to fire an action potential. This will in turn cause the muscles in the chromatophores to contract.
We feel compelled to point out that the music making the squid cells jump would not have been audible during the experiment. That's because all the current that would normally have been converted into sound was being channeled into the cells. But even with the track layered over the video after the fact, the experiment is a pretty compelling demonstration of the common ground between biology and technology.