In this TedTalk, we see how electrical stimulation of neurons can trigger activity in a severed cockroach leg. And lemme tell ya, this cockroach can dance.
A little background may be in order. Tim Marzullo and Greg Gage wanted to show high school students what neural signals look like, without an enormous amount of expensive equipment. After finishing grad school, they founded an educational equipment company, Backyard Brains. Now that company manufactures open-source equipment and produces accompanying lesson plans to explain and demonstrate how our brain works.
So where does the cockroach come in? Since our brains work by transmitting electrical stimuli between neurons, the stimulation of cockroach neurons demonstrates the principles without the unpleasant mess of brain surgery. However, a bit of roach surgery is required.
In the TedTalk, Greg leads the audience through the first experiment available at their website. The initial steps include anaesthesizing a cockroach, removal of a leg, connection of the leg to the company's SpikerBox. All in a day's work.
Once the box is turned on, we can hear the neurons communicating with each other. As Greg points out, this rain-like noise is the sound our brains make.
Once the SpikerBox is to connected to a mobile device with their free app, we can see the spikes:
The device also allows for the leg to receive electrical stimulation from an external source. Essentially, the leg is "hearing" what we receive through earbuds connected to our phones or mp3 devices. (Musically inclined geeks can also beatbox to the leg.) Apparently the leg likes the beat.
Recently, Tim explained Backyard Brain's latest product, RoboRoach, to Slashdot TV. If you haven't seen a cockroach wearing a backpack -- or being remote controlled -- this is a must-see video.
RoboRoach works by replacing the nerve in the cockroach's antenna with a silver electrode. Once the backpack is attached, you can control the insect's movements for a few minutes. Turns out, cockroaches adapt fairly quickly.
When you return the cockroach to it's cage for ~20 minutes, he "forgets" and the stimulation works again. ... After about 2-7 days, the stimulation stops working altogether, so you can clip the wires and retire the cockroach to your breeder colony to spend the rest of its days making more cockroaches for you and eating your lettuce.
Don't have any cockroaches on hand? No worries. For the Spikerbox experiment you can substitute crickets, although they may not work with RoboRoach. For that, you need an insect capable of carrying the 4.4 gram device. Luckily, Backyard Brains will send you a box of roaches for $24.