A Flexible‐Substrate 5‐µm‐Diameter Needle Electrode: Minimizing Neuronal Death and Enabling Year‐Long Neural Recording

Abstract

Long‐term quantitative observations of the physiological state of the brain are essential technologies in various fields. In vivo electrophysiology with microelectrodes enables high spatiotemporal recordings of neuronal activities; however, tissue damage occurs due to electrode penetration, which limits the recording period. A neural recording technology is introduced that uses a 5‐µm‐diameter microneedle electrode device. The electrode implanted in the mouse cortex shows in vivo recording capabilities 1 day after implantation, which exceeds the year‐long duration. The electrode does not significantly increase neuronal death compare with tissue without electrode implantation. A noise‐reduced recording configuration is also demonstrated for the microneedle electrode, which enhances the recording performance for freely moving animals.