In one embodiment, a system for electrically stimulating neural tissue of a patient and for determining neurotransmitter release in response to stimulation, the system comprises: pulse generating circuitry for generating electrical pulses; at least one electrical lead for conducting electrical pulses generated by the pulse generating circuitry to neural tissue, the at least one electrical lead comprising a plurality of electrodes; at least one electrochemical sensor for sensing an extracellular level of one or several neurotransmitters; circuitry for sampling a signal from the at least one electrochemical sensor; a controller for automatically applying stimulation to neural tissue using a plurality of electrode combinations, the controller generating data related to neurotransmitter release for each of the plurality of electrode combinations; and a display for displaying neurotransmitter release for electrode combinations to a clinician.