They listen in when nerve cells communicate with one another: neural probes planted permanently in the brain. Photo: IMTEK/Müller What is going on in this rat’s head, anyway? It shows symptoms of epilepsy, of that the researchers at the Epilepsy Center of the Freiburg University Medical Center are certain. But where in the rat’s brain is the transmitter that’s interfering with the signals and causing some of its nerve cells to interrupt the highly specialized, independent signal processing, and why is this happening at all? Instead – this much is known about the disease – the cells are send- ing their electronic pulses at the same time and in the same rhythm. As a consequence, the rat loses control over the regions of its body connected to the nerve cells and experiences epileptic seizures. 700,000 people suffer from epilepsy in Germany alone and are familiar with Small Size, Big Effect Scientists Use Neural Probes to Record Communication between Nerve Cells by Anita Rüffer this “storm in the brain.” Epilepsy is the most common brain disease. The scientists are con- ducting experiments on animal models to find out how to prevent a seizure by sending the right electric signals in the right place in order to in- duce the nerve cells to return to their normal rhythm. Many exciting questions of the neurosciences, medicine, and biology would still be awaiting an answer if it weren’t for microsystems engineer- ing. “We deliver the scientific tools necessary to find out what is happening in the brain,” explains Dr. Patrick Ruther, research assistant under Prof. Dr. Oliver Paul at the Laboratory for Microsystem Materials. Ruther, one of 20 assistants at the De- 4