A Reconfigurable Multisite ECoG Electrode Array for Recording from Multiple Cortical Regions

초록

The simultaneous measurement of neural signals from multiple cortical regions in freely moving mice is fundamental for a comprehensive understanding of intricately connected neural circuits. However, in mice, which are commonly utilized in neuroscience research, the restricted dimensions of the brain and skull present significant challenges for the implantation of electrodes across multiple cortical areas. Furthermore, the acquisition of neural activity from multiple brain regions frequently necessitates extensive craniotomy, a procedure that inherently carries a substantial risk of neural damage. A micro-sized electrocorticography (ECoG) electrode arrays, fabricated utilizing micro-electromechanical system (MEMS) technology, have been developed for accurately accessing multiple cortical areas individually and for preventing damage to neural tissues. The micro-sized electrode. Nevertheless, such MEMS-fabricated arrays possess an immutable configuration post-manufacturing. Consequently, the interrogation of new cortical regions mandates complete device re-fabrication, thereby incurring substantial temporal and financial expenditure. To overcome these limitations, we have developed a reconfigurable multisite ECoG electrode array that allows access to multiple desired cortical regions within a single platform through simple adjustments. The design features a reconfigurable arrangement for packaging the ECoG electrodes and the printed circuit board (PCB), enabling flexible access to diverse cortical regions. While the ECoG electrodes are mass-produced using MEMS technology with a parylene substrate, their circular design for PCB packaging allows for flexible repositioning. This design enables the creation of an ECoG electrode array capable of simultaneous neural signal recording from various murine brain regions within a single platform, eliminating the need for re- fabrication. Furthermore, the electrodes are fabricated to a thickness of 6 µm for excellent conformance to the curved cortical surface, and coated with PEDO T:PSS via electrophoresis to enhance recording performance. Using this reconfigurable multisite ECoG electrode array, we successfully performed simultaneous and precise measurements of neural activity from two distinct cortical regions in freely moving mice. From these results, we believe that the flexible design and packaging method presented in the developed ECoG electrode can be widely used in various neuroscience studies.