Development of an anatomically conformal parylene neural probe array for multi-region hippocampal recordings

Abstract

We report the first Parylene C neural probe array that is anatomically matched to multiple regions of the hippocampus and successfully demonstrate recordings from targeted regions. No prior polymer probe array has achieved recordings at the depth of the hippocampus (5.5 mm probe length) and at such a high electrode density (64 electrodes). In addition, bare probes were implanted without the use of any insertion shuttles thereby enabling, for the first time, acquisition of dense neural information from deep brain targets of interest while restricting acute tissue disruption to the as-fabricated probe cross-section. Here, we present design and fabrication of the Parylene neural array, its electrical packaging scheme, and acute, in vivo recordings from pyramidal cells of both the cornu ammonis (CA) 1 and CA3 regions, essential players in the one-way hippocampal circuit that encodes memory.