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.