I found an article on this topic in Discovery magazine (Dec 06). The online version isn't very helpful, so here's an excerpt form wired.com
http://www.wired.com/news/technology/medtech/0,71457-0.html
Basically, they cultured rat neurons on an electrical sensor. Then, they connected it to a digital interface. The robotic rats display primitive functions controlled by the neurons on the petri dish.
Is this new technology? Sounds interesting to me.