Figure 2.

Amperometric biosensors are sensitive to in vitro and in vivo changes in lactate concentration ([lac]). A) In vitro calibration of a lactate sensitive biosensor. Arrows depict the addition of lactate (0.25mM). Lactate biosensors rapidly (~1s) produce an increase in current in response to changes in [Lac] that is linear across the expected range of [Lac] in vivo (see inset). B) Baseline electrical stimulations of the perforant path in an individual produce reliable changes in extracellular [lac]. Triangles depict each stimulation wherein 15, 200uS pulses were delivered at 50Hz. C) Average change in [Lac] observed during baseline stimulation in an individual rat. Following stimulation, extracellular [Lac] initially decreases followed by an overshoot of pre-stimulation levels.