An Integrated System for Simultaneous, Multichannel Neuronal Stimulation and Recording

Precision electronics that provide multi-electrode stimulation and recording capabilities are an important tool for the experimental study of neuronal development and plasticity. Towards this end, we present a custom analog integrated circuit (IC), fabricated in a 0.35-mum process, incorporating stimulation buffers and recording preamplifiers for multiple electrodes onto a single die. The architecture of the IC allows for arbitrary, independent configuration of electrodes for stimulation or recording, and the IC includes artifact-elimination circuitry that returns the stimulation electrode to its previous voltage following stimulation, minimizing the interference with recording. We analyze the thermal noise levels in the recording preamplifiers and experimentally measure input-referred noise as low as 4.77 muV_rms in the frequency range of 30 Hz-3 kHz at a power consumption of 100 muW from a total power supply of 3.8 V. We also consider the temporal response and stability of the artifact elimination circuitry. We demonstrate that the use of the artifact-elimination circuitry with a 30-mum diameter stimulation electrode permits a return to recording mode in les 2 ms after stimulation, facilitating near-simultaneous stimulation and recording of neuronal signals. (Patent applied for, U.S. No. 2007/0178579.)