Semiconductor chips and neuronal systems can be electrically coupled on a microscopic level. This research provides the fundament for an application of such hybrid processors in brain research, neuroprosthetics and information technology. On the neuronal side, ion channels, nerve cells and brain tissue are employed. On the electronic side, simple silicon chips with transistors and capacitors are used for the elucidation of the coupling mechanism. On that basis, complex chips are developed with more that 30000 contact sites to supervise neuronal activity with highest spatial resolution.