A 13μm CMOS SoC for simultaneous multichannel optogenetics and electrophysiological brain recording

Optogenetics and multi-unit electrophysiological recording are state-of-the-art approaches in neuroscience to observe neural microcircuits in vivo [1]. Thereby, brain-implantable devices incorporating optical stimulation and low-noise data acquisition means have been designed based on custom integrated circuits (IC) to study the brain of small freely behaving laboratory animals. However, no existing IC provides multichannel optogenetic photo-stimulation along with multi-unit electrophysiological recording capability within the same die [2-5]. They also lack critical features: they are not multichannel and/or do not include an ADC [6], or they address only one signal modality [5-6], i.e., either local field potentials (LFP) or action potentials (AP). In this paper, we report an IC for simultaneous multichannel optogenetics and electrophysiological recording addressing both LFP and AP signals all at once. This 0.13μm CMOS chip, which includes 4/10 stimulation/recording channels, is enclosed inside a small wireless optogenetic platform, and is demonstrated with simultaneous in vivo optical stimulation and electrophysiological recordings with a virally mediated Channelrhodopsin-2 (ChR2) rat.