Simultaneous microelectrode recording of layered structure of cortex and tonotopic structure of thalamus in the auditory pathway

Hirokazu Takahashi, Tomoyo I. Shiramatsu, Kazusa Takahashi, Takahiro Noda, Ryohei Kanzaki, Haruka Nakahara

Abstract: Simultaneous characterization of layer-specific activation in the cortex and topographically organized activation in the thalamus brings substantial benefits to advance the understanding of the sensory/motor functions. We designed a silicon-probe microelectrode array to simultaneously characterize the primary auditory cortex (A1) and thalamus (medial geniculate body; MGB), which are aligned in the dosro-lateral to ventro-medial axis perpendicular to the cortical surface of A1. The array had 3 shanks with 6-mm length. On each shank, 15 recording sites were made at the tip for MGB and 17 sites were made at the bottom for A1. A laser displacement meter was proved useful to make appropriate insertion of the array probe at a right angle with respect to the cortical surface. Our experiments in vivo demonstrated the capability of the designed array to investigate the thalamo-cortical interaction between tonotopically organized activities in the thalamus and layer-specific activities in the cortex.