Bioamplifiers are devices that can be used to actually visualize neuron action potential; the ability to use impulses to stimulate muscle movement. Greg Gage and Tim Marzullo have created Backyard Brains, which sells bioamplifiers called SpikerBoxes that allow at-home scientists and students to explore neuroscience. Simply connect electrodes to invertebrate legs, like from a cockroach, and listen to the neurons. When connected to an mp3 player, you can even get the leg to dance along with the beat.
Gage decided to apply the same principles of dancing cockroach legs to squid chromatophores, which are similar to melanocytes in that they contain pigments, though they also reflect light. Squid chromatophores can be highly reactive, as animals may need to change color quickly in order to avoid detection by predators. Gage isolated a squids fin nerve and surrounding chromatophore-containing muscle, and subjected it those impulses.
As it turns out, the chromatophore responds best to a heavy bass line. Bass frequencies have longer waves, which charge neural membranes longer and get a better action potential. The cells are also able to ‘dance’ along with the beat due to the fact that mp3 players output AC signals, of which the current can be reversed through the neural membrane. DC signals cannot, and would likely only produce a single twitch of the cells, which isn’t nearly as fun.
Gage magnified the squid cells 8x and played “Insane in the Brain” by Cypress Hill because of the bass (and also doubles as a neuroscience pun). They have dubbed the video “Insane in the Chromatophores,” and it is totally awesome.
In honor of Cephalopod Week, check it out:
[Hat tip: Andreas von Bubnoff, Science Friday]