Fig. 3: Monolithic in-vivo integration of neural interface system.

a Schematic illustration of neural interface system. b Optical stereomicrograph of neural interface system applied to a mouse. Scale bar, 1 mm. c Schematic illustrations showing the position of neural probes and the cranial interconnections. d Impedance map of implanted electrode arrays. e Single-unit traces of 12-channel neural probe arrays in mouse brain after 16 weeks post-implantation. MO motor cortex, HIP hippocampus, VIS visual cortex, LH and RH left and right hemisphere, respectively. Scale bars, 200 µV (vertical) and 500 ms (horizontal). f PCA-clustered single-unit spikes for each channel. Scale bars, 100 µV (vertical) and 2 ms (horizontal). g LFPs recorded from hippocampus in RH by channel 9 (red) and 10 (blue). Scale bars, 500 µV (vertical) and 200 ms (horizontal). h Superimposed theta waves and corresponding theta angles extracted from LFPs of (g). i Mean signal amplitudes of single-unit spikes recorded at 12 soft neural probes for 33 weeks of chronic recording. Each data point indicates the average of ten measurements, and error bars represent the standard deviation. j Time evolution of PCA-clustered single-unit spikes from channel 10 over 33 weeks after injection. k Single-unit spikes recorded at a channel 10 for 33 weeks of chronic recording. Scale bars, 100 µV (vertical) and 0.5 ms (horizontal). 3D-reconstructed confocal micrograph (l) and fluorescence micrograph (m) showing implanted neural probes in hippocampal region. Yellow lines indicate the boundary of the implanted neural probe. Scale bars, 100 µm. Normalized fluorescence intensity of neurons (n), astrocyte and microglia (o) as a function of the distance from the boundaries of the implanted neural probe (n = 6). Each data point indicates the average of five measurements from each probe-implanted tissue taken from six mice, and error bars represent the standard deviation.