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Floating microelectrode arrays chronically implanted into the feline peripheral nerve elicit a characteristic tissue response
Author(s) -
Kolarcik Christi L,
Puglisi Kelly,
Lesniak Andrew,
Demetris Anthony J,
Fisher Lee E,
Gaunt Robert A
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.659.1
Subject(s) - luxol fast blue stain , neuroscience , dorsal root ganglion , microelectrode , nissl body , medicine , spinal nerve , astrocyte , peripheral nerve injury , pathology , sensory system , biology , chemistry , anatomy , spinal cord , staining , central nervous system , peripheral nerve , myelin , electrode
Neural interfacing technologies have the potential to significantly improve the quality of life of patients that are severely disabled or suffering from a variety of neurodegenerative conditions. To recapitulate proper physiological function, motor commands and sensory feedback must be considered. The spinal nerve is a unique location at which these complementary systems can be accessed. In this study, the dorsal root ganglion‐ventral root (DRG‐VR) complex was targeted with floating microelectrode arrays (FMAs) designed either to record from the VR or test stimulation paradigms in the DRG. Extensive characterization of the tissue response to these chronically implanted microelectrode arrays was performed to determine the reliability of these peripheral locations for interfacing applications. To accomplish these analyses, hematoxylin and eosin and Nissl/Luxol fast blue staining along with antibody‐based stains [NF200 (axons), S100 (Schwann cells), vimentin (fibroblasts, endothelial cells, astrocytes), MAC387(monocytes/macrophages), GLUT1 (glucose transport proteins)] were employed, regions of interest representing the entire area of the implanted array defined, and pixel‐based image analyses specific for each stain utilized. Implanted roots were compared to the non‐implanted (i.e., contralateral) roots from the same cohort of animals. The results indicate that the inflammatory reaction elicited with array insertion is not significantly greater than what is observed in a control (i.e., non‐implanted) spinal nerve. The absence of a significant immune response to these arrays suggests some level of immune privilege in the spinal nerve and bodes well for long‐term applications. In addition, no significant decreases in neuronal density or myelination were observed in the area associated with the array indicating that both neuronal cell bodies and axonal projections are maintained. Observations related to the status of the blood‐nerve barrier suggest it is preserved and/or reestablished at the chronic time points examined. Our data indicates that targeting the DRG‐VR complex is a viable option and that the associated tissue response in this location is an opportunity to achieve the overall goal of a long‐term, reliable interface with prosthetic limbs. Support or Funding Information This work was sponsored by the Defense Advanced Research Projects Agency (DARPA) Microsystems Technology Office under the auspices of Dr. Jack Judy through the Space and Naval Warfare Systems Center, Pacific Grant No. N66001‐11‐C‐4171.