Comparison of Glial Reactivity in Cortex Below Electrode Arrays with and without ECM Coatings.

(A) Cortical sections labeled for microglia/macrophages (Iba1, top rows) or astrocytes (GFAP, middle rows) at 7 or 30 days post-implantation. Bottom rows are the overlay of the sections. (B) Mean cortical reactivity from ECM coated arrays (normalized to the contralateral region). Dashed lines represent the reactivity generated from uncoated array implantation. Data is presented as the mean ± standard error of the mean, n = 4 for each electrode type at each time point. * denotes p<0.05, ** denotes p<0.01, and *** denotes p<0.001. Scale bar = 500 μm. (C) Mean Iba1+ cell counts were obtained by quantifying positive cells from cortical sections labeled for microglia/macrophages at 7 or 30 days post-implantation. (D) Fewer Iba1 positive cells were found in cortex below electrodes coated in collagen or collagen-fibronectin than the uncoated control electrodes. Data is presented as mean ± standard error of the mean, n = 4 for each electrode type at each time point. Data was compared with one-way ANOVA. * denotes p<0.05. Scale bar = 100 μm.