Figure 6.

Hyperphosphorylated tau surrounding chronically implanted microelectrodes 16 weeks post-implant. (A–C) Representative images of pT231 immunostained pretangles. (B) Boxed region in (A) at higher magnification. Note the increased presence of pT231 staining near non-specifically stained hemosiderin-laden macrophages. (C) Additional example from another implant showing the pT231 positive signal surrounding the electrode. Arrows indicate labeled diffuse granular pretangles and arrow heads indicate rodlike dystrophic neurites. (D) Positive control—human Alzheimer's case sections contained stained processes similar to those seen around electrodes. The scale bar is 50 μm (A) and 10 μm (B–D). Figure and caption reprinted with permission from McConnell et al. (2009b). © IOP Publishing. All rights reserved. Tau protein misfolding and neuronal degeneration cause irreversible signal disruption that may be compensable with algorithmic strategies.