Brain in a Dish

Researchers created "minibrains" in a petridish by growing rat neurons on top of an electorode. The neurons can control the device the electorde is connected to. It can recieve information, process it, and then send out a response, such as moving toward a light. The researchers had some difficulty when the neurons would randomly fire. They realized that this was caused by sensory deprivation, because in a brain, neurons are constantly recieving information. To compensate for this, they provided a background stimulation, that would allow the neurons to function normally.
http://www.discover.com/issues/nov-06/rd/minibrains-dishes/