Fig. 4.

Chronic changes in LFP spectral components. (a) Average changes in power at different frequency bands from 1 dpi, calculated by dividing the power at postimplantation dates by that of 1 dpi. Numbers on the top row show the number of animals at that specific time point. Some dates had $<6$ animals due to the lack of enough artifact-free signals (see Sec. 2 for criteria). Note the increase in high-gamma signal throughout recording duration and the increase in delta oscillations at chronic time points. (b), (c) The trend of change in high-gamma power normalized to 1 dpi with SEM indicated by shadowed area in (b) and error bars in (c). (d) Average PSD at 1 dpi, 2 to 6 months, and 6 to 12 months postimplantation. (e) PSD normalized to 1 dpi averaged at 2- to 6-month and 6- to 12-month windows. Note the increase at low-and high-frequency bands, but the change in other frequency bands are less prominent. Shaded area for all figures indicates $\pm \mathrm{SEM}$.