Microminiature Interconnect technologies (MITI) proposes to develop one and two dimensional microminiature electrode arrays for recording electrical activity simultaneously from equally spaced locations throughout extended volumes of brain tissue with minimal tissue damage. Since many investigators employ in vitro slices of living brain tissue to study self-contained neural systems amenable to intracellular and optical recording and drug application, they are proposing probe designs applicable to both brain slice recording and whole animal studies. In Phase I, a proof-of-concept demonstration of a linear 16 contact array for recording from brain slices will be developed with assistance from the Albert Einstein College of Medicine. In Phase II, they will modify this design into a two- dimensional array of contacts capable of sampling neuronal activity over a relatively large area of a neural system such as a thick cortical slice of tissue. MITI has extensive experience in the development of microminiature devices with a wide range of applications, including watches and semiconductors.