Detection of electrophysiological activities in the F7 area of the rhesus macaque cortex during recovery from prolonged anesthesia using implantable microelectrode array

Anesthesia plays a crucial role in regulating physiological states during medical procedures, but its effects on neural activity remain incompletely understood, particularly at the prefrontal cortical level. The prefrontal cortex is essential for various cognitive and motor functions, yet high-spatiotemporal-resolution electrodes at the cellular level remain challenging to develop, which has hindered the acquisition of detailed electrophysiological data from anesthetized subjects. Here, we design a 16-channel silicon-based microelectrode array (MEA), which, after modification with platinum black nanoparticles, exhibits significantly reduced impedance (22.5 kΩ) and increased phase (−33.5°), enhancing its electrical performance and electrophysiological signal detection capabilities. Using this modified MEA, we have recorded cellular-level neural activity during the recovery process of a rhesus macaque following prolonged anesthesia. Over a 660 s period, we observed a gradual increase in the neuronal firing rate in the F7 area, along with distinctive patterns in local field potentials across different frequency bands. Notably, power in the δ and θ bands increased continuously during recovery, highlighting their potential role in the transition from anesthesia to wakefulness. Our findings provide new insights into the dynamic recovery process of cortical neurons and offer a powerful tool for high-spatiotemporal-resolution neural monitoring in nonhuman primates.