A polymer probe-based system for high density, long-lasting electrophysiological recordings across distributed neuronal circuits

The brain is a massively interconnected neuronal network, organized into specialized circuits consisting of large ensembles of neurons distributed across anatomically connected regions. While circuit computations depend upon millisecond timescale interactions, the structure of the underlying networks are remodeled on timescales ranging from seconds to months. Current approaches lack the combination of resolution, spatial coverage, longevity, and stability to measure the detailed dynamics of these networks. Here we describe a large-scale, multisite recording platform that integrates polymer electrodes with a modular stacking headstage design supporting up to 1024 channels of recording in freely-behaving rats. We show that the integrated system can yield months-long recordings from hundreds of well-isolated units across multiple regions. Moreover, the recordings are stable enough to track a substantial fraction of single units for over a week. This platform enables large-scale electrophysiological interrogation of the function and evolution of distributed circuits throughout an animal9s adult life.