Integrated Optical Neural Probe

In certain embodiments, a neural probe comprises a substrate comprising elongated shanks for penetrating neural tissue, each comprising a proximal end and a distal end; at least one optical source integral to the neural probe for illuminating the neural tissue; and microelectrodes located proximate the distal end of the elongated shanks for monitoring neuronal activity. In certain embodiments, a method of monitoring neuronal activity comprises implanting the neural probe into a test subject such that the elongated shanks protrude into neural tissue of the test subject; illuminating the neural tissue with the at least one optical source; and measuring neuronal activity in response to illuminating the neural tissue. In certain embodiments, a device comprises a semiconductor chip; at least one optical source integral to the semiconductor chip; and sensor elements integral to the semiconductor chip for collecting data responsive to light emitted from the at least one optical source.