SWCNTs/PEDOT:PSS-modified microelectrode arrays reveal striatal–hippocampal neural encoding of movement initiation and place fields during goal-directed navigation

Abstract

Goal-directed navigation necessitates coordinated interactions among multiple brain regions, with the hippocampus and striatum playing critical roles in spatial representation, movement-related information, and reward-related evaluation. The hippocampus, particularly the cornu ammonis 1 (CA1) region, is renowned for its role in spatial encoding via place cells. The striatum, a basal ganglia nucleus, can integrate cortical, thalamic, and limbic inputs to regulate motor planning, reward valuation, and behavioral flexibility. Despite extensive research, a key challenge remains: the lack of high-spatiotemporal-resolution, high-precision, and multi-channel electrodes that are structurally matched for reliable implantation across multiple brain regions. To address this, we developed two silicon-based microelectrode arrays (MEAs) anatomically tailored for dual-region neuronal electrophysiological recording of the striatum and CA1. By modifying the electrode sites with single-walled carbon nanotubes (SWCNTs)/poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) nanocomposites, we significantly enhanced the electrical performance, reducing impedance and phase delay. Leveraging this platform, we demonstrated that neurons in the rat ventral striatum (vStr) contribute to movement initiation, transmitting information to CA1, while CA1 place cells dynamically encode new goal locations and relay spatial information to neurons in the dorsal striatum (dStr). This research provides a reliable platform for exploring the neural interactions between the striatum and hippocampus, establishing a foundation for future studies on neural circuits in complex behaviors.