A transparent electrode array for simultaneous cortical potential recording and intrinsic signal optical imaging

Intrinsic signal optical imaging (ISOI) is a technique that enables researchers to relate changes in cortical activity in response to stimuli by measuring changes in hemoglobin oxygenation and local blood volume. As the time course of these changes - local blood volume in particular - is of the order of seconds, the neural activity that initiates these changes is only indirectly acquired in ISOI. To better correlate these events, it is beneficial to simultaneously record both the evoked cortical potentials and ISOI. In this study we present a novel, transparent, recording array that allows the combination of optical imaging with electrical recordings without the use of metal electrodes in the observation field. Pilot data were recorded after visual and electrical stimuli of the eye to prove the concept.