The foreign body response to the Utah Slant Electrode Array in the cat sciatic nerve

Area of Science:

• Biomaterials science
• Neuroscience
• Histology

Background:

• Assessing biocompatibility of chronic indwelling electrodes is crucial for neuroprosthetic research.
• Studies on foreign body reactions to penetrating microelectrodes in peripheral nerves are limited.

Purpose of the Study:

• To investigate the foreign body response to the Utah Slant Electrode Array in the cat sciatic nerve.
• To evaluate long-term biocompatibility of indwelling microelectrode arrays.

Main Methods:

• Histological analysis of cat sciatic nerves with implanted Utah Slant Electrode Arrays.
• Examination of tissue response at various time points up to 350 days post-implantation.

Main Results:

• Increased activated macrophages observed at and distal to the implant site.
• Compensatory nerve regeneration with shifts towards smaller diameter nerve fibers.
• Axonal growth around microelectrode shafts noted, with normal nerve fibers distant from the implant.

Conclusions:

• The cat sciatic nerve exhibits a foreign body response and regenerative adaptations to chronic microelectrode implantation.
• Long-term implantation reveals nerve fiber composition changes and axonal remodeling near the device.
• Understanding these responses is vital for developing effective neuroprosthetic interfaces.