Implantable Neural Microelectrodes: How to Reduce Immune Response

Abstract

Implantable neural microelectrodes exhibit the great ability to accurately capture the electrophysiological signals from individual neurons with exceptional submillisecond precision, holding tremendous potential for advancing brain science research, as well as offering promising avenues for neurological disease therapy. Although significant advancements have been made in the channel and density of implantable neural microelectrodes, challenges persist in extending the stable recording duration of these microelectrodes. The enduring stability of implanted electrode signals is primarily influenced by the chronic immune response triggered by the slight movement of the electrode within the neural tissue. The intensity of this immune response increases with a higher bending stiffness of the electrode. This Review thoroughly analyzes the sequential reactions evoked by implanted electrodes in the brain and highlights strategies aimed at mitigating chronic immune responses. Minimizing immune response mainly includes designing the microelectrode structure, selecting flexible materials, surface modification, and controlling drug release. The purpose of this paper is to provide valuable references and ideas for reducing the immune response of implantable neural microelectrodes and stimulate their further exploration in the field of brain science.

Large scale, simultaneous, chronic neural recordings from multiple brain areas

“…We then set out to compare single unit yield. A major concern with chronic recordings is tissue health: unhealthy craniotomies or inflammation may reduce single unit yield due to gliosis or other immune factors (Hermann and Capadona, 2018; Xiang et al, 2024). The single unit yield on our recordings was comparable if not higher than that of IBL recordings (Fig.…”