Figure 3.

Schematic representation of the cellular response to a neuroprosthetic implant. (A) Location of implant featuring a Utah Array, ribbon cable and percutaneous pedestal secured to the skull. Dashed box represents the location of the close-up views in (B–D). (B) Cellular organization prior to device implantation. (C) Acute injury response featuring microglia and astrocyte adhesion to the implant surface, as well as a variety of cellular responses local to the implant, including acute inflammation, extravasated red and white blood cells, myelin debris, edema and damaged neurons. (D) Chronic injury response to a neuroprosthetic implant featuring isomorphic glial scar and neuronal death local to the implant and surrounded by anisomorphic glial scar at a distance from the implant. The acute inflammation has subsided and edema and cellular debris is cleared. Meningeal fibroblasts are not shown, but may contribute a fibrotic component to the scar depending on characteristics of the device and implantation procedure. Features are not drawn to scale.