A chronic micropositioning system for neurophysiology

Microelectrode arrays fabricated for monitoring single and multi-neuronal action potentials often fail to record from the same population of neurons over a period of time. The number of recorded neurons tends to decrease due to micromotion of neurons away from the microelectrode, gliosis around the recording site and also brain movement due to behavior. We report here for the first time, a novel electrostatic microactuator based positioning system that will enable chronic tracking of single neurons. The electrostatic microactuators are fabricated using the SUMMiT/spl trade/ (Sandia's Ultraplanar Multilevel MEMS Technology) process, a 5-layer polysilicon micromachining technology of the Sandia National Labs, NM. The microfabricated microactuators enable precise positioning of microelectrodes in the brain and subsequently upon implantation track specific neurons with minimal behavioral hindrance. The micropositioning system has been designed for chronic precision electrophysiology in rodents. We believe however, that this system will greatly enable precision monitoring and intervention during brain function and dysfunction.