A Compact Wireless Headstage based Optogenetic Neuromodulation and 32-channel Electrophysiological Recording System

This paper demonstrates a commercial off-the-shelf components (COTS)-based miniaturized wireless optogenetic headstage with simultaneous optical stimulation and electro-physiological recording capability for freely moving rodents. The proposed headstage contains 32 recording channels. The optical stimulation system is a battery-powered neural stimulator, comprised of a low dropout regulator (LDO), an oscillator, and a µLED. The electrophysiological signal recording system includes an intracortical neural probe made of a GaN-on-silicon substrate, an array of neural amplifiers with an integrated analog-to-digital converter (ADC), a transceiver integrated circuit, and a ceramic antenna. The integrated MUX with the ADC allows sampling of the amplified voltage at a sampling rate of 4000 kSamples/s. By placing the headstage on the head of a rodent and recording the neural signals from the Ventral Tegmental area of the brain, the system is experimentally validated in in-vivo. Experimental result shows that the proposed headstage can trigger neuron activity while collecting and detecting single-cell microvolt amplitude activity from multiple channels.