A microelectrode array incorporating an optical waveguide device for stimulation and spatiotemporal electrical recording of neural activity.

Targeted neural excitation coupled with simultaneous multineuron recording is desirable both for studying the real-time dynamics of neural circuits and for prospective clinical treatment of neurological diseases. Optical stimulation of genetically targeted neurons expressing the light sensitive channel protein Channelrhodopsin (ChR2) has recently been reported as a means for millisecond temporal control of neuronal spiking activity with cell-type selectivity. This offers the prospect of enabling local (cellular level) stimulation and the concomitant monitoring of neural activity by extracellular electrophysiological methods, both in the vicinity of and distant to the stimulation site. We report here a novel dual-modality hybrid device which consists of a tapered coaxial optical waveguide ("optrode") directly integrated into a 100 element intra-cortical multi-electrode recording array. The dual-modality array device was used in ChR2 transfected mouse brain slices. Specifically, epileptiform events were reliably optically triggered by the optrode and their spatiotemporal patterns were simultaneously recorded by the multi-electrode array.