An MRI-compatible electrode implantation system for linking behavioral neurophysiology and stimulation-evoked fMRI in non-human primates.

Local electrophysiology and microstimulation reveal site-specific neural activity and physiological effects but do not directly link these local effects to whole-brain responses from the same target site. We developed an MRI-compatible electrode implantation system for macaques that enables CT/MRI-based localization, postoperative depth adjustment, neural recording, microstimulation during behavioral testing, and subsequent electrical microstimulation combined with functional MRI (EM-fMRI) using the same implanted electrode. The system supported local field potential recording, a stimulation-induced reduction in pupil size, and distributed stimulation-evoked blood oxygenation level-dependent (BOLD) responses. This approach provides a practical framework for linking local neural activity and stimulation-induced physiological responses with whole-brain responses at the same target site.